Initial import from SVN

1 files changed, 3464 insertions, 0 deletions

diff --git a/projects/net.wotonomy.web/src/main/java/net/wotonomy/web/URI.java b/projects/net.wotonomy.web/src/main/java/net/wotonomy/web/URI.java
new file mode 100644
index 0000000..41f77f5
--- /dev/null
+++ b/projects/net.wotonomy.web/src/main/java/net/wotonomy/web/URI.java
@@ -0,0 +1,3464 @@
+/*
+ * $Header$
+ * $Revision: 905 $
+ * $Date: 2006-02-18 20:44:03 -0500 (Sat, 18 Feb 2006) $
+ *
+ * ====================================================================
+ *
+ * The Apache Software License, Version 1.1
+ *
+ * Copyright (c) 2002 the Apache Software Foundation.  All rights 
+ * reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer. 
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * 3. The end-user documentation included with the redistribution, if
+ *    any, must include the following acknowlegement:  
+ *       "This product includes software developed by the 
+ *        Apache Software Foundation (http://www.apache.org/)."
+ *    Alternately, this acknowlegement may appear in the software itself,
+ *    if and wherever such third-party acknowlegements normally appear.
+ *
+ * 4. The names "The Jakarta Project", "HttpClient", and "Apache Software
+ *    Foundation" must not be used to endorse or promote products derived
+ *    from this software without prior written permission. For written 
+ *    permission, please contact apache@apache.org.
+ *
+ * 5. Products derived from this software may not be called "Apache"
+ *    nor may "Apache" appear in their names without prior written
+ *    permission of the Apache Group.
+ *
+ * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
+ * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
+ * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ * ====================================================================
+ *
+ * This software consists of voluntary contributions made by many
+ * individuals on behalf of the Apache Software Foundation.  For more
+ * information on the Apache Software Foundation, please see
+ * <http://www.apache.org/>.
+ *
+ * [Additional notices, if required by prior licensing conditions]
+ *
+ */ 
+
+// excellent class borrowed from Apache Commons project:
+//package org.apache.commons.httpclient;
+
+package net.wotonomy.web;
+
+import java.io.IOException;
+import java.io.Serializable;
+import java.io.UnsupportedEncodingException;
+import java.net.URL;
+import java.security.AccessController;
+import java.util.BitSet;
+import java.util.Hashtable;
+import java.util.Locale;
+
+import sun.security.action.GetPropertyAction;
+
+/**
+ * The interface for the URI(Uniform Resource Identifiers) version of RFC 2396.
+ * This class has the purpose of supportting of parsing a URI reference to
+ * extend any specific protocols, the character encoding of the protocol to 
+ * be transported and the charset of the document.
+ * <p>
+ * A URI is always in an "escaped" form, since escaping or unescaping a
+ * completed URI might change its semantics.  
+ * <p>
+ * Implementers should be careful not to escape or unescape the same string
+ * more than once, since unescaping an already unescaped string might lead to
+ * misinterpreting a percent data character as another escaped character,
+ * or vice versa in the case of escaping an already escaped string.
+ * <p>
+ * In order to avoid these problems, data types used as follows:
+ * <p><blockquote><pre>
+ *   URI character sequence: char
+ *   octet sequence: byte
+ *   original character sequence: String
+ * </pre></blockquote><p>
+ *
+ * So, a URI is a sequence of characters as an array of a char type, which
+ * is not always represented as a sequence of octets as an array of byte.
+ * <p>
+ * 
+ * URI Syntactic Components
+ * <p><blockquote><pre>
+ * - In general, written as follows:
+ *   Absolute URI = &lt;scheme&gt:&lt;scheme-specific-part&gt;
+ *   Generic URI = &lt;scheme&gt;://&lt;authority&gt;&lt;path&gt;?&lt;query&gt;
+ *
+ * - Syntax
+ *   absoluteURI   = scheme ":" ( hier_part | opaque_part )
+ *   hier_part     = ( net_path | abs_path ) [ "?" query ]
+ *   net_path      = "//" authority [ abs_path ]
+ *   abs_path      = "/"  path_segments
+ * </pre></blockquote><p>
+ *
+ * The following examples illustrate URI that are in common use.
+ * <pre>
+ * ftp://ftp.is.co.za/rfc/rfc1808.txt
+ *    -- ftp scheme for File Transfer Protocol services
+ * gopher://spinaltap.micro.umn.edu/00/Weather/California/Los%20Angeles
+ *    -- gopher scheme for Gopher and Gopher+ Protocol services
+ * http://www.math.uio.no/faq/compression-faq/part1.html
+ *    -- http scheme for Hypertext Transfer Protocol services
+ * mailto:mduerst@ifi.unizh.ch
+ *    -- mailto scheme for electronic mail addresses
+ * news:comp.infosystems.www.servers.unix
+ *    -- news scheme for USENET news groups and articles
+ * telnet://melvyl.ucop.edu/
+ *    -- telnet scheme for interactive services via the TELNET Protocol
+ * </pre>
+ * Please, notice that there are many modifications from URL(RFC 1738) and
+ * relative URL(RFC 1808).
+ * <p>
+ * <b>The expressions for a URI</b>
+ * <p><pre>
+ * For escaped URI forms
+ *  - URI(char[]) // constructor
+ *  - char[] getRawXxx() // method
+ *  - String getEscapedXxx() // method
+ *  - String toString() // method
+ * <p>
+ * For unescaped URI forms
+ *  - URI(String) // constructor
+ *  - String getXXX() // method
+ * </pre><p>
+ *
+ * @author <a href="mailto:jericho@apache.org">Sung-Gu</a>
+ * @version $Revision: 905 $ $Date: 2002/03/14 15:14:01 
+ */
+class URI implements Cloneable, Comparable, Serializable {
+
+
+    // ----------------------------------------------------------- Constructors
+
+    protected URI() {
+    }
+
+    /**
+     * Construct a URI as an escaped form of a character array.
+     * An URI can be placed within double-quotes or angle brackets like 
+     * "http://test.com/" and &lt;http://test.com/&gt;
+     * 
+     * @param escaped the URI character sequence
+     * @exception IOException
+     * @throws NullPointerException if <code>escaped</code> is <code>null</code>
+     */
+    public URI(char[] escaped) throws IOException {
+        parseUriReference(new String(escaped), true);
+    }
+
+
+    /**
+     * Construct a URI from the given string.
+     * <p><blockquote><pre>
+     *   URI-reference = [ absoluteURI | relativeURI ] [ "#" fragment ]
+     * </pre></blockquote><p>
+     * An URI can be placed within double-quotes or angle brackets like 
+     * "http://test.com/" and &lt;http://test.com/&gt;
+     *
+     * @param original the string to be represented to URI character sequence
+     * It is one of absoluteURI and relativeURI.
+     * @exception IOException
+     */
+    public URI(String original) throws IOException {
+        parseUriReference(original, false);
+    }
+
+    /**
+     * Construct a URI from a URL.
+     *
+     * @param url a valid URL.
+     * @throws IOException
+     * @since 2.0 
+     */
+    public URI(URL url) throws IOException {
+        this(url.toString());
+    }
+
+
+    /**
+     * Construct a general URI from the given components.
+     * <p><blockquote><pre>
+     *   URI-reference = [ absoluteURI | relativeURI ] [ "#" fragment ]
+     *   absoluteURI   = scheme ":" ( hier_part | opaque_part )
+     *   opaque_part   = uric_no_slash *uric
+     * </pre></blockquote><p>
+     * It's for absolute URI = &lt;scheme&gt;:&lt;scheme-specific-part&gt;#
+     * &lt;fragment&gt;.
+     *
+     * @param scheme the scheme string
+     * @param scheme_specific_part scheme_specific_part
+     * @param fragment the fragment string
+     * @exception IOException
+     */
+    public URI(String scheme, String scheme_specific_part, String fragment)
+        throws IOException {
+
+        // validate and contruct the URI character sequence
+        if (scheme == null) {
+           throw new IOException(/*IOException.PARSING,*/ "URI: scheme required");
+        }
+        char[] s = scheme.toLowerCase().toCharArray();
+        if (validate(s, URI.scheme)) {
+            _scheme = s; // is_absoluteURI
+        } else {
+            throw new IOException(/*IOException.PARSING,*/ "URI: incorrect scheme");
+        }
+        _opaque = encode(scheme_specific_part, allowed_opaque_part);
+        // Set flag
+        _is_opaque_part = true;
+        setUriReference();
+    }
+
+
+    /**
+     * Construct a general URI from the given components.
+     * <p><blockquote><pre>
+     *   URI-reference = [ absoluteURI | relativeURI ] [ "#" fragment ]
+     *   absoluteURI   = scheme ":" ( hier_part | opaque_part )
+     *   relativeURI   = ( net_path | abs_path | rel_path ) [ "?" query ]
+     *   hier_part     = ( net_path | abs_path ) [ "?" query ]
+     * </pre></blockquote><p>
+     * It's for absolute URI = &lt;scheme&gt;:&lt;path&gt;?&lt;query&gt;#&lt;
+     * fragment&gt; and relative URI = &lt;path&gt;?&lt;query&gt;#&lt;fragment
+     * &gt;.
+     *
+     * @param scheme the scheme string
+     * @param authority the authority string
+     * @param path the path string
+     * @param query the query string
+     * @param fragment the fragment string
+     * @exception IOException
+     */
+    public URI(String scheme, String authority, String path, String query,
+               String fragment) throws IOException {
+
+        // validate and contruct the URI character sequence
+        StringBuffer buff = new StringBuffer();
+        if (scheme != null) {
+            buff.append(scheme);
+            buff.append(':');
+        }
+        if (authority != null) {
+            buff.append("//");
+            buff.append(authority);
+        }
+        if (path != null) {  // accept empty path
+            if ((scheme != null || authority != null)
+                    && !path.startsWith("/")) {
+                throw new IOException(/*IOException.PARSING*,*/
+                        "URI: abs_path requested");
+            }
+            buff.append(path);
+        }
+        if (query != null) {
+            buff.append('?');
+            buff.append(query);
+        }
+        if (fragment != null) {
+            buff.append('#');
+            buff.append(fragment);
+        }
+        parseUriReference(buff.toString(), false);
+    }
+
+
+    /**
+     * Construct a general URI from the given components.
+     *
+     * @param scheme the scheme string
+     * @param userinfo the userinfo string
+     * @param host the host string
+     * @param port the port number
+     * @exception IOException
+     */
+    public URI(String scheme, String userinfo, String host, int port)
+        throws IOException {
+
+        this(scheme, userinfo, host, port, null, null, null);
+    }
+
+
+    /**
+     * Construct a general URI from the given components.
+     *
+     * @param scheme the scheme string
+     * @param userinfo the userinfo string
+     * @param host the host string
+     * @param port the port number
+     * @param path the path string
+     * @exception IOException
+     */
+    public URI(String scheme, String userinfo, String host, int port,
+            String path) throws IOException {
+
+        this(scheme, userinfo, host, port, path, null, null);
+    }
+
+
+    /**
+     * Construct a general URI from the given components.
+     *
+     * @param scheme the scheme string
+     * @param userinfo the userinfo string
+     * @param host the host string
+     * @param port the port number
+     * @param path the path string
+     * @param query the query string
+     * @exception IOException
+     */
+    public URI(String scheme, String userinfo, String host, int port,
+            String path, String query) throws IOException {
+
+        this(scheme, userinfo, host, port, path, query, null);
+    }
+
+
+    /**
+     * Construct a general URI from the given components.
+     *
+     * @param scheme the scheme string
+     * @param userinfo the userinfo string
+     * @param host the host string
+     * @param port the port number
+     * @param path the path string
+     * @param query the query string
+     * @param fragment the fragment string
+     * @exception IOException
+     */
+    public URI(String scheme, String userinfo, String host, int port,
+            String path, String query, String fragment) throws IOException {
+
+        this(scheme, (host == null) ? null :
+                ((userinfo != null) ? userinfo + '@' : "") + host +
+                ((port != -1) ? ":" + port : ""), path, query, fragment);
+    }
+
+
+    /**
+     * Construct a general URI from the given components.
+     *
+     * @param scheme the scheme string
+     * @param host the host string
+     * @param path the path string
+     * @param fragment the fragment string
+     * @exception IOException
+     */
+    public URI(String scheme, String host, String path, String fragment)
+        throws IOException {
+
+        this(scheme, host, path, null, fragment);
+    }
+
+
+    /**
+     * Construct a general URI with the given relative URI string.
+     *
+     * @param base the base URI
+     * @param relative the relative URI string
+     * @exception IOException
+     */
+    public URI(URI base, String relative) throws IOException {
+        this(base, new URI(relative));
+    }
+
+
+    /**
+     * Construct a general URI with the given relative URI.
+     * <p><blockquote><pre>
+     *   URI-reference = [ absoluteURI | relativeURI ] [ "#" fragment ]
+     *   relativeURI   = ( net_path | abs_path | rel_path ) [ "?" query ]
+     * </pre></blockquote><p>
+     * Resolving Relative References to Absolute Form.
+     *
+     * <strong>Examples of Resolving Relative URI References</strong>
+     *
+     * Within an object with a well-defined base URI of
+     * <p><blockquote><pre>
+     *   http://a/b/c/d;p?q
+     * </pre></blockquote><p>
+     * the relative URI would be resolved as follows:
+     *
+     * Normal Examples
+     *
+     * <p><blockquote><pre>
+     *   g:h           =  g:h
+     *   g             =  http://a/b/c/g
+     *   ./g           =  http://a/b/c/g
+     *   g/            =  http://a/b/c/g/
+     *   /g            =  http://a/g
+     *   //g           =  http://g
+     *   ?y            =  http://a/b/c/?y
+     *   g?y           =  http://a/b/c/g?y
+     *   #s            =  (current document)#s
+     *   g#s           =  http://a/b/c/g#s
+     *   g?y#s         =  http://a/b/c/g?y#s
+     *   ;x            =  http://a/b/c/;x
+     *   g;x           =  http://a/b/c/g;x
+     *   g;x?y#s       =  http://a/b/c/g;x?y#s
+     *   .             =  http://a/b/c/
+     *   ./            =  http://a/b/c/
+     *   ..            =  http://a/b/
+     *   ../           =  http://a/b/
+     *   ../g          =  http://a/b/g
+     *   ../..         =  http://a/
+     *   ../../        =  http://a/ 
+     *   ../../g       =  http://a/g
+     * </pre></blockquote><p>
+     *
+     * Some URI schemes do not allow a hierarchical syntax matching the
+     * <hier_part> syntax, and thus cannot use relative references.
+     *
+     * @param base the base URI
+     * @param relative the relative URI
+     * @exception IOException
+     */
+    public URI(URI base, URI relative) throws IOException {
+
+        if (base._scheme == null) {
+            throw new IOException(/* IOException.PARSING,*/ "URI: base URI required");
+        }
+        if (base._scheme != null) {
+            this._scheme = base._scheme;
+            this._authority = base._authority;
+        }
+        if (base._is_opaque_part || relative._is_opaque_part) {
+            this._scheme = base._scheme;
+            this._is_opaque_part = relative._is_opaque_part;
+            this._opaque = relative._opaque;
+            this._fragment = relative._fragment;
+            this.setUriReference();
+            return;
+        }
+        if (relative._scheme != null) {
+            this._scheme = relative._scheme;
+            this._is_net_path = relative._is_net_path;
+            this._authority = relative._authority;
+            if (relative._is_server) {
+                this._userinfo = relative._userinfo;
+                this._host = relative._host;
+                this._port = relative._port;
+            } else if (relative._is_reg_name) {
+                this._is_reg_name = relative._is_reg_name;
+            }
+            this._is_abs_path = relative._is_abs_path;
+            this._is_rel_path = relative._is_rel_path;
+            this._path = relative._path;
+        } else if (base._authority != null && relative._scheme == null) {
+            this._is_net_path = base._is_net_path;
+            this._authority = base._authority;
+            if (base._is_server) {
+                this._userinfo = base._userinfo;
+                this._host = base._host;
+                this._port = base._port;
+            } else if (base._is_reg_name) {
+                this._is_reg_name = base._is_reg_name;
+            }
+        }
+        if (relative._authority != null) {
+            this._is_net_path = relative._is_net_path;
+            this._authority = relative._authority;
+            if (relative._is_server) {
+                this._is_server = relative._is_server;
+                this._userinfo = relative._userinfo;
+                this._host = relative._host;
+                this._port = relative._port;
+            } else if (relative._is_reg_name) {
+                this._is_reg_name = relative._is_reg_name;
+            }
+            this._is_abs_path = relative._is_abs_path;
+            this._is_rel_path = relative._is_rel_path;
+            this._path = relative._path;
+        }
+        // resolve the path
+        if (relative._scheme == null && relative._authority == null || 
+                equals(base._scheme, relative._scheme)) {
+            this._path = resolvePath(base._path, relative._path);
+        }
+        // base._query removed
+        if (relative._query != null) {
+            this._query = relative._query;
+        }
+        // base._fragment removed
+        if (relative._fragment != null) {
+            this._fragment = relative._fragment;
+        }
+        this.setUriReference();
+    }
+
+    // --------------------------------------------------- Instance Variables
+
+    static final long serialVersionUID = 604752400577948726L;
+
+
+    /**
+     * This Uniform Resource Identifier (URI).
+     * The URI is always in an "escaped" form, since escaping or unescaping
+     * a completed URI might change its semantics.  
+     */
+    protected char[] _uri = null;
+
+
+    /**
+     * The default charset of the protocol.  RFC 2277, 2396
+     */
+    protected static String _protocolCharset = "UTF-8";
+
+
+    /**
+     * The default charset of the document.  RFC 2277, 2396
+     * The platform's charset is used for the document by default.
+     */
+    protected static String _documentCharset = null;
+    // Static initializer for _documentCharset
+    static {
+        Locale locale = Locale.getDefault();
+        if (locale != null) {
+            // in order to support backward compatiblity
+            _documentCharset = LocaleToCharsetMap.getCharset(locale);
+        } else {
+            _documentCharset = (String)AccessController.doPrivileged(
+                    new GetPropertyAction("file.encoding"));
+        }
+    }
+
+    /**
+     * The scheme.
+     */
+    protected char[] _scheme = null;
+
+
+    /**
+     * The opaque.
+     */
+    protected char[] _opaque = null;
+
+
+    /**
+     * The authority.
+     */
+    protected char[] _authority = null;
+
+
+    /**
+     * The userinfo.
+     */
+    protected char[] _userinfo = null;
+
+
+    /**
+     * The host.
+     */
+    protected char[] _host = null;
+
+
+    /**
+     * The port.
+     */
+    protected int _port = -1;
+
+
+    /**
+     * The path.
+     */
+    protected char[] _path = null;
+
+
+    /**
+     * The query.
+     */
+    protected char[] _query = null;
+
+
+    /**
+     * The fragment.
+     */
+    protected char[] _fragment = null;
+
+
+    /**
+     * The root path.
+     */
+    protected static char[] rootPath = { '/' };
+
+    // ---------------------- Generous characters for each component validation
+
+    /**
+     * The percent "%" character always has the reserved purpose of being the
+     * escape indicator, it must be escaped as "%25" in order to be used as
+     * data within a URI.
+     */
+    protected static final BitSet percent = new BitSet(256);
+    // Static initializer for percent
+    static {
+        percent.set('%');
+    }
+
+
+    /**
+     * BitSet for digit.
+     * <p><blockquote><pre>
+     * digit    = "0" | "1" | "2" | "3" | "4" | "5" | "6" | "7" |
+     *            "8" | "9"
+     * </pre></blockquote><p>
+     */
+    protected static final BitSet digit = new BitSet(256);
+    // Static initializer for digit
+    static {
+        for(int i = '0'; i <= '9'; i++) {
+            digit.set(i);
+        }
+    }
+
+
+    /**
+     * BitSet for alpha.
+     * <p><blockquote><pre>
+     * alpha         = lowalpha | upalpha
+     * </pre></blockquote><p>
+     */
+    protected static final BitSet alpha = new BitSet(256);
+    // Static initializer for alpha
+    static {
+        for (int i = 'a'; i <= 'z'; i++) {
+            alpha.set(i);
+        }
+        for (int i = 'A'; i <= 'Z'; i++) {
+            alpha.set(i);
+        }
+    }
+
+
+    /**
+     * BitSet for alphanum (join of alpha &amp; digit).
+     * <p><blockquote><pre>
+     *  alphanum      = alpha | digit
+     * </pre></blockquote><p>
+     */
+    protected static final BitSet alphanum = new BitSet(256);
+    // Static initializer for alphanum
+    static {
+        alphanum.or(alpha);
+        alphanum.or(digit);
+    }
+
+
+    /**
+     * BitSet for hex.
+     * <p><blockquote><pre>
+     * hex           = digit | "A" | "B" | "C" | "D" | "E" | "F" |
+     *                         "a" | "b" | "c" | "d" | "e" | "f"
+     * </pre></blockquote><p>
+     */
+    protected static final BitSet hex = new BitSet(256);
+    // Static initializer for hex
+    static {
+        hex.or(digit);
+        for(int i = 'a'; i <= 'f'; i++) {
+            hex.set(i);
+        }
+        for(int i = 'A'; i <= 'F'; i++) {
+            hex.set(i);
+        }
+    }
+
+
+    /**
+     * BitSet for escaped.
+     * <p><blockquote><pre>
+     * escaped       = "%" hex hex
+     * </pre></blockquote><p>
+     */
+    protected static final BitSet escaped = new BitSet(256);
+    // Static initializer for escaped
+    static {
+        escaped.or(percent);
+        escaped.or(hex);
+    }
+
+
+    /**
+     * BitSet for mark.
+     * <p><blockquote><pre>
+     * mark          = "-" | "_" | "." | "!" | "~" | "*" | "'" |
+     *                 "(" | ")"
+     * </pre></blockquote><p>
+     */
+    protected static final BitSet mark = new BitSet(256);
+    // Static initializer for mark
+    static {
+        mark.set('-');
+        mark.set('_');
+        mark.set('.');
+        mark.set('!');
+        mark.set('~');
+        mark.set('*');
+        mark.set('\'');
+        mark.set('(');
+        mark.set(')');
+    }
+
+
+    /**
+     * Data characters that are allowed in a URI but do not have a reserved
+     * purpose are called unreserved.
+     * <p><blockquote><pre>
+     * unreserved    = alphanum | mark
+     * </pre></blockquote><p>
+     */
+    protected static final BitSet unreserved = new BitSet(256);
+    // Static initializer for unreserved
+    static {
+        unreserved.or(alphanum);
+        unreserved.or(mark);
+    }
+
+
+    /**
+     * BitSet for reserved.
+     * <p><blockquote><pre>
+     * reserved      = ";" | "/" | "?" | ":" | "@" | "&amp;" | "=" | "+" |
+     *                 "$" | ","
+     * </pre></blockquote><p>
+     */
+    protected static final BitSet reserved = new BitSet(256);
+    // Static initializer for reserved
+    static {
+        reserved.set(';');
+        reserved.set('/');
+        reserved.set('?');
+        reserved.set(':');
+        reserved.set('@');
+        reserved.set('&');
+        reserved.set('=');
+        reserved.set('+');
+        reserved.set('$');
+        reserved.set(',');
+    }
+
+
+    /**
+     * BitSet for uric.
+     * <p><blockquote><pre>
+     * uric          = reserved | unreserved | escaped
+     * </pre></blockquote><p>
+     */
+    protected static final BitSet uric = new BitSet(256);
+    // Static initializer for uric
+    static {
+        uric.or(reserved);
+        uric.or(unreserved);
+        uric.or(escaped);
+    }
+
+
+    /**
+     * BitSet for fragment (alias for uric).
+     * <p><blockquote><pre>
+     * fragment      = *uric
+     * </pre></blockquote><p>
+     */
+    protected static final BitSet fragment = uric;
+
+
+    /**
+     * BitSet for query (alias for uric).
+     * <p><blockquote><pre>
+     * query         = *uric
+     * </pre></blockquote><p>
+     */
+    protected static final BitSet query = uric;
+
+
+    /**
+     * BitSet for pchar.
+     * <p><blockquote><pre>
+     * pchar         = unreserved | escaped |
+     *                 ":" | "@" | "&amp;" | "=" | "+" | "$" | ","
+     * </pre></blockquote><p>
+     */
+    protected static final BitSet pchar = new BitSet(256);
+    // Static initializer for pchar
+    static {
+        pchar.or(unreserved);
+        pchar.or(escaped);
+        pchar.set(':');
+        pchar.set('@');
+        pchar.set('&');
+        pchar.set('=');
+        pchar.set('+');
+        pchar.set('$');
+        pchar.set(',');
+    }
+
+
+    /**
+     * BitSet for param (alias for pchar).
+     * <p><blockquote><pre>
+     * param         = *pchar
+     * </pre></blockquote><p>
+     */
+    protected static final BitSet param = pchar;
+
+
+    /**
+     * BitSet for segment.
+     * <p><blockquote><pre>
+     * segment       = *pchar *( ";" param )
+     * </pre></blockquote><p>
+     */
+    protected static final BitSet segment = new BitSet(256);
+    // Static initializer for segment
+    static {
+        segment.or(pchar);
+        segment.set(';');
+        segment.or(param);
+    }
+
+
+    /**
+     * BitSet for path segments.
+     * <p><blockquote><pre>
+     * path_segments = segment *( "/" segment )
+     * </pre></blockquote><p>
+     */
+    protected static final BitSet path_segments = new BitSet(256);
+    // Static initializer for path_segments
+    static {
+        path_segments.set('/');
+        path_segments.or(segment);
+    }
+
+
+    /**
+     * URI absolute path.
+     * <p><blockquote><pre>
+     * abs_path      = "/"  path_segments
+     * </pre><blockquote><p>
+     */
+    protected static final BitSet abs_path = new BitSet(256);
+    // Static initializer for abs_path
+    static {
+        abs_path.set('/');
+        abs_path.or(path_segments);
+    }
+
+
+    /**
+     * URI bitset for encoding typical non-slash characters.
+     * <p><blockquote><pre>
+     * uric_no_slash = unreserved | escaped | ";" | "?" | ":" | "@" |
+     *                 "&amp;" | "=" | "+" | "$" | ","
+     * </pre></blockquote><p>
+     */
+    protected static final BitSet uric_no_slash = new BitSet(256);
+    // Static initializer for uric_no_slash
+    static {
+        uric_no_slash.or(unreserved);
+        uric_no_slash.or(escaped);
+        uric_no_slash.set(';');
+        uric_no_slash.set('?');
+        uric_no_slash.set(';');
+        uric_no_slash.set('@');
+        uric_no_slash.set('&');
+        uric_no_slash.set('=');
+        uric_no_slash.set('+');
+        uric_no_slash.set('$');
+        uric_no_slash.set(',');
+    }
+    
+
+    /**
+     * URI bitset that combines uric_no_slash and uric.
+     * <p><blockquote><pre>
+     * opaque_part   = uric_no_slash *uric
+     * </pre></blockquote><p>
+     */
+    protected static final BitSet opaque_part = new BitSet(256);
+    // Static initializer for opaque_part
+    static {
+        opaque_part.or(uric_no_slash);
+        opaque_part.or(uric);
+    }
+    
+
+    /**
+     * URI bitset that combines absolute path and opaque part.
+     * <p><blockquote><pre>
+     * path          = [ abs_path | opaque_part ]
+     * </pre></blockquote><p>
+     */
+    protected static final BitSet path = new BitSet(256);
+    // Static initializer for path
+    static {
+        path.or(abs_path);
+        path.or(opaque_part);
+    }
+
+
+    /**
+     * Port, a logical alias for digit.
+     */
+    protected static final BitSet port = digit;
+
+
+    /**
+     * Bitset that combines digit and dot fo IPv$address.
+     * <p><blockquote><pre>
+     * IPv4address   = 1*digit "." 1*digit "." 1*digit "." 1*digit
+     * </pre></blockquote><p>
+     */
+    protected static final BitSet IPv4address = new BitSet(256);
+    // Static initializer for IPv4address
+    static {
+        IPv4address.or(digit);
+        IPv4address.set('.');
+    }
+
+
+    /**
+     * RFC 2373.
+     * <p><blockquote><pre>
+     * IPv6address = hexpart [ ":" IPv4address ]
+     * </pre></blockquote><p>
+     */
+    protected static final BitSet IPv6address = new BitSet(256);
+    // Static initializer for IPv6address reference
+    static {
+        IPv6address.or(hex); // hexpart
+        IPv6address.set(':');
+        IPv6address.or(IPv4address);
+    }
+
+
+    /**
+     * RFC 2732, 2373.
+     * <p><blockquote><pre>
+     * IPv6reference   = "[" IPv6address "]"
+     * </pre></blockquote><p>
+     */
+    protected static final BitSet IPv6reference = new BitSet(256);
+    // Static initializer for IPv6reference
+    static {
+        IPv6reference.set('[');
+        IPv6reference.or(IPv6address);
+        IPv6reference.set(']');
+    }
+
+
+    /**
+     * BitSet for toplabel.
+     * <p><blockquote><pre>
+     * toplabel      = alpha | alpha *( alphanum | "-" ) alphanum
+     * </pre></blockquote><p>
+     */
+    protected static final BitSet toplabel = new BitSet(256);
+    // Static initializer for toplabel
+    static {
+        toplabel.or(alphanum);
+        toplabel.set('-');
+    }
+
+
+    /**
+     * BitSet for domainlabel.
+     * <p><blockquote><pre>
+     * domainlabel   = alphanum | alphanum *( alphanum | "-" ) alphanum
+     * </pre></blockquote><p>
+     */
+    protected static final BitSet domainlabel = toplabel;
+
+
+    /**
+     * BitSet for hostname.
+     * <p><blockquote><pre>
+     * hostname      = *( domainlabel "." ) toplabel [ "." ]
+     * </pre></blockquote><p>
+     */
+    protected static final BitSet hostname = new BitSet(256);
+    // Static initializer for hostname
+    static {
+        hostname.or(toplabel);
+        // hostname.or(domainlabel);
+        hostname.set('.');
+    }
+
+
+    /**
+     * BitSet for host.
+     * <p><blockquote><pre>
+     * host          = hostname | IPv4address | IPv6reference
+     * </pre></blockquote><p>
+     */
+    protected static final BitSet host = new BitSet(256);
+    // Static initializer for host
+    static {
+        host.or(hostname);
+        // host.or(IPv4address);
+        host.or(IPv6reference); // IPv4address
+    }
+
+
+    /**
+     * BitSet for hostport.
+     * <p><blockquote><pre>
+     * hostport      = host [ ":" port ]
+     * </pre></blockquote><p>
+     */
+    protected static final BitSet hostport = new BitSet(256);
+    // Static initializer for hostport
+    static {
+        hostport.or(host);
+        hostport.set(':');
+        hostport.or(port);
+    }
+
+
+    /**
+     * Bitset for userinfo.
+     * <p><blockquote><pre>
+     * userinfo      = *( unreserved | escaped |
+     *                    ";" | ":" | "&amp;" | "=" | "+" | "$" | "," )
+     * </pre></blockquote><p>
+     */
+    protected static final BitSet userinfo = new BitSet(256);
+    // Static initializer for userinfo
+    static {
+        userinfo.or(unreserved);
+        userinfo.or(escaped);
+        userinfo.set(';');
+        userinfo.set(':');
+        userinfo.set('&');
+        userinfo.set('=');
+        userinfo.set('+');
+        userinfo.set('$');
+        userinfo.set(',');
+    }
+
+
+    /**
+     * BitSet for within the userinfo component like user and password.
+     */
+    public static final BitSet within_userinfo = new BitSet(256);
+    // Static initializer for within_userinfo
+    static {
+        within_userinfo.or(userinfo);
+        within_userinfo.clear(';'); // reserved within authority
+        within_userinfo.clear(':');
+        within_userinfo.clear('@');
+        within_userinfo.clear('?');
+        within_userinfo.clear('/');
+    }
+
+
+    /**
+     * Bitset for server.
+     * <p><blockquote><pre>
+     * server        = [ [ userinfo "@" ] hostport ]
+     * </pre></blockquote><p>
+     */
+    protected static final BitSet server = new BitSet(256);
+    // Static initializer for server
+    static {
+        server.or(userinfo);
+        server.set('@');
+        server.or(hostport);
+    }
+
+
+    /**
+     * BitSet for reg_name.
+     * <p><blockquote><pre>
+     * reg_name      = 1*( unreserved | escaped | "$" | "," |
+     *                     ";" | ":" | "@" | "&amp;" | "=" | "+" )
+     * </pre></blockquote><p>
+     */
+    protected static final BitSet reg_name = new BitSet(256);
+    // Static initializer for reg_name
+    static {
+        reg_name.or(unreserved);
+        reg_name.or(escaped);
+        reg_name.set('$');
+        reg_name.set(',');
+        reg_name.set(';');
+        reg_name.set(':');
+        reg_name.set('@');
+        reg_name.set('&');
+        reg_name.set('=');
+        reg_name.set('+');
+    }
+
+
+    /**
+     * BitSet for authority.
+     * <p><blockquote><pre>
+     * authority     = server | reg_name
+     * </pre></blockquote><p>
+     */
+    protected static final BitSet authority = new BitSet(256);
+    // Static initializer for authority
+    static {
+        authority.or(server);
+        authority.or(reg_name);
+    }
+
+
+    /**
+     * BitSet for scheme.
+     * <p><blockquote><pre>
+     * scheme        = alpha *( alpha | digit | "+" | "-" | "." )
+     * </pre></blockquote><p>
+     */
+    protected static final BitSet scheme = new BitSet(256);
+    // Static initializer for scheme
+    static {
+        scheme.or(alpha);
+        scheme.or(digit);
+        scheme.set('+');
+        scheme.set('-');
+        scheme.set('.');
+    }
+
+
+    /**
+     * BitSet for rel_segment.
+     * <p><blockquote><pre>
+     * rel_segment   = 1*( unreserved | escaped |
+     *                     ";" | "@" | "&amp;" | "=" | "+" | "$" | "," )
+     * </pre></blockquote><p>
+     */
+    protected static final BitSet rel_segment = new BitSet(256);
+    // Static initializer for rel_segment
+    static {
+        rel_segment.or(unreserved);
+        rel_segment.or(escaped);
+        rel_segment.set(';');
+        rel_segment.set('@');
+        rel_segment.set('&');
+        rel_segment.set('=');
+        rel_segment.set('+');
+        rel_segment.set('$');
+        rel_segment.set(',');
+    }
+
+
+    /**
+     * BitSet for rel_path.
+     * <p><blockquote><pre>
+     * rel_path      = rel_segment [ abs_path ]
+     * </pre></blockquote><p>
+     */
+    protected static final BitSet rel_path = new BitSet(256);
+    // Static initializer for rel_path
+    static {
+        rel_path.or(rel_segment);
+        rel_path.or(abs_path);
+    }
+
+
+    /**
+     * BitSet for net_path.
+     * <p><blockquote><pre>
+     * net_path      = "//" authority [ abs_path ]
+     * </pre></blockquote><p>
+     */
+    protected static final BitSet net_path = new BitSet(256);
+    // Static initializer for net_path
+    static {
+        net_path.set('/');
+        net_path.or(authority);
+        net_path.or(abs_path);
+    }
+    
+
+    /**
+     * BitSet for hier_part.
+     * <p><blockquote><pre>
+     * hier_part     = ( net_path | abs_path ) [ "?" query ]
+     * </pre></blockquote><p>
+     */
+    protected static final BitSet hier_part = new BitSet(256);
+    // Static initializer for hier_part
+    static {
+        hier_part.or(net_path);
+        hier_part.or(abs_path);
+        // hier_part.set('?'); aleady included
+        hier_part.or(query);
+    }
+
+
+    /**
+     * BitSet for relativeURI.
+     * <p><blockquote><pre>
+     * relativeURI   = ( net_path | abs_path | rel_path ) [ "?" query ]
+     * </pre></blockquote><p>
+     */
+    protected static final BitSet relativeURI = new BitSet(256);
+    // Static initializer for relativeURI
+    static {
+        relativeURI.or(net_path);
+        relativeURI.or(abs_path);
+        relativeURI.or(rel_path);
+        // relativeURI.set('?'); aleady included
+        relativeURI.or(query);
+    }
+
+
+    /**
+     * BitSet for absoluteURI.
+     * <p><blockquote><pre>
+     * absoluteURI   = scheme ":" ( hier_part | opaque_part )
+     * </pre></blockquote><p>
+     */
+    protected static final BitSet absoluteURI = new BitSet(256);
+    // Static initializer for absoluteURI
+    static {
+        absoluteURI.or(scheme);
+        absoluteURI.set(':');
+        absoluteURI.or(hier_part);
+        absoluteURI.or(opaque_part);
+    }
+
+
+    /**
+     * BitSet for URI-reference.
+     * <p><blockquote><pre>
+     * URI-reference = [ absoluteURI | relativeURI ] [ "#" fragment ]
+     * </pre></blockquote><p>
+     */
+    protected static final BitSet URI_reference = new BitSet(256);
+    // Static initializer for URI_reference
+    static {
+        URI_reference.or(absoluteURI);
+        URI_reference.or(relativeURI);
+        URI_reference.set('#');
+        URI_reference.or(fragment);
+    }
+
+    // ---------------------------- Characters disallowed within the URI syntax
+    // Excluded US-ASCII Characters are like control, space, delims and unwise
+
+    /**
+     * BitSet for control.
+     */
+    public static final BitSet control = new BitSet(256);
+    // Static initializer for control
+    static {
+        for (int i = 0; i <= 0x1F; i++) {
+            control.set(i);
+        }
+        control.set(0x7F);
+    }
+
+    /**
+     * BitSet for space.
+     */
+    public static final BitSet space = new BitSet(256);
+    // Static initializer for space
+    static {
+        space.set(0x20);
+    }
+
+
+    /**
+     * BitSet for delims.
+     */
+    public static final BitSet delims = new BitSet(256);
+    // Static initializer for delims
+    static {
+        delims.set('<');
+        delims.set('>');
+        delims.set('#');
+        delims.set('%');
+        delims.set('"');
+    }
+
+
+    /**
+     * BitSet for unwise.
+     */
+    public static final BitSet unwise = new BitSet(256);
+    // Static initializer for unwise
+    static {
+        unwise.set('{');
+        unwise.set('}');
+        unwise.set('|');
+        unwise.set('\\');
+        unwise.set('^');
+        unwise.set('[');
+        unwise.set(']');
+        unwise.set('`');
+    }
+
+
+    /**
+     * Disallowed rel_path before escaping.
+     */
+    public static final BitSet disallowed_rel_path = new BitSet(256);
+    // Static initializer for disallowed_rel_path
+    static {
+        disallowed_rel_path.or(uric);
+        disallowed_rel_path.andNot(rel_path);
+    }
+
+
+    /**
+     * Disallowed opaque_part before escaping.
+     */
+    public static final BitSet disallowed_opaque_part = new BitSet(256);
+    // Static initializer for disallowed_opaque_part
+    static {
+        disallowed_opaque_part.or(uric);
+        disallowed_opaque_part.andNot(opaque_part);
+    }
+
+    // ----------------------- Characters allowed within and for each component
+
+    /**
+     * Those characters that are allowed for the authority component.
+     */
+    public static final BitSet allowed_authority = new BitSet(256);
+    // Static initializer for allowed_authority
+    static {
+        allowed_authority.or(authority);
+        allowed_authority.clear('%');
+    }
+
+
+    /**
+     * Those characters that are allowed for the opaque_part.
+     */
+    public static final BitSet allowed_opaque_part = new BitSet(256);
+    // Static initializer for allowed_opaque_part 
+    static {
+        allowed_opaque_part.or(opaque_part);
+        allowed_opaque_part.clear('%');
+    }
+
+
+    /**
+     * Those characters that are allowed for the reg_name.
+     */
+    public static final BitSet allowed_reg_name = new BitSet(256);
+    // Static initializer for allowed_reg_name 
+    static {
+        allowed_reg_name.or(reg_name);
+        // allowed_reg_name.andNot(percent);
+        allowed_reg_name.clear('%');
+    }
+
+
+    /**
+     * Those characters that are allowed for the userinfo component.
+     */
+    public static final BitSet allowed_userinfo = new BitSet(256);
+    // Static initializer for allowed_userinfo
+    static {
+        allowed_userinfo.or(userinfo);
+        // allowed_userinfo.andNot(percent);
+        allowed_userinfo.clear('%');
+    }
+
+
+    /**
+     * Those characters that are allowed for within the userinfo component.
+     */
+    public static final BitSet allowed_within_userinfo = new BitSet(256);
+    // Static initializer for allowed_within_userinfo
+    static {
+        allowed_within_userinfo.or(within_userinfo);
+        allowed_within_userinfo.clear('%');
+    }
+
+
+    /**
+     * Those characters that are allowed for the IPv6reference component.
+     * The characters '[', ']' in IPv6reference should be excluded.
+     */
+    public static final BitSet allowed_IPv6reference = new BitSet(256);
+    // Static initializer for allowed_IPv6reference
+    static {
+        allowed_IPv6reference.or(IPv6reference);
+        // allowed_IPv6reference.andNot(unwise);
+        allowed_IPv6reference.clear('[');
+        allowed_IPv6reference.clear(']');
+    }
+
+
+    /**
+     * Those characters that are allowed for the host component.
+     * The characters '[', ']' in IPv6reference should be excluded.
+     */
+    public static final BitSet allowed_host = new BitSet(256);
+    // Static initializer for allowed_host
+    static {
+        allowed_host.or(hostname);
+        allowed_host.or(allowed_IPv6reference);
+    }
+
+
+    /**
+     * Those characters that are allowed for the authority component.
+     */
+    public static final BitSet allowed_within_authority = new BitSet(256);
+    // Static initializer for allowed_within_authority
+    static {
+        allowed_within_authority.or(server);
+        allowed_within_authority.or(reg_name);
+        allowed_within_authority.clear(';');
+        allowed_within_authority.clear(':');
+        allowed_within_authority.clear('@');
+        allowed_within_authority.clear('?');
+        allowed_within_authority.clear('/');
+    }
+
+
+    /**
+     * Those characters that are allowed for the abs_path.
+     */
+    public static final BitSet allowed_abs_path = new BitSet(256);
+    // Static initializer for allowed_abs_path
+    static {
+        allowed_abs_path.or(abs_path);
+        // allowed_abs_path.set('/');  // aleady included
+        allowed_abs_path.andNot(percent);
+    }
+
+
+    /**
+     * Those characters that are allowed for the rel_path.
+     */
+    public static final BitSet allowed_rel_path = new BitSet(256);
+    // Static initializer for allowed_rel_path
+    static {
+        allowed_rel_path.or(rel_path);
+        allowed_rel_path.clear('%');
+    }
+
+
+    /**
+     * Those characters that are allowed within the path.
+     */
+    public static final BitSet allowed_within_path = new BitSet(256);
+    // Static initializer for allowed_within_path
+    static {
+        allowed_within_path.or(abs_path);
+        allowed_within_path.clear('/');
+        allowed_within_path.clear(';');
+        allowed_within_path.clear('=');
+        allowed_within_path.clear('?');
+    }
+
+
+    /**
+     * Those characters that are allowed for the query component.
+     */
+    public static final BitSet allowed_query = new BitSet(256);
+    // Static initializer for allowed_query
+    static {
+        allowed_query.or(uric);
+        allowed_query.clear('%');
+    }
+
+
+    /**
+     * Those characters that are allowed within the query component.
+     */
+    public static final BitSet allowed_within_query = new BitSet(256);
+    // Static initializer for allowed_within_query
+    static {
+        allowed_within_query.or(allowed_query);
+        allowed_within_query.andNot(reserved); // excluded 'reserved'
+        allowed_within_query.clear('#'); // avoid confict with the fragment
+    }
+
+
+    /**
+     * Those characters that are allowed for the fragment component.
+     */
+    public static final BitSet allowed_fragment = new BitSet(256);
+    // Static initializer for allowed_fragment
+    static {
+        allowed_fragment.or(uric);
+        allowed_fragment.clear('%');
+    }
+
+    // ------------------------------------------- Flags for this URI-reference
+
+    // URI-reference = [ absoluteURI | relativeURI ] [ "#" fragment ]
+    // absoluteURI   = scheme ":" ( hier_part | opaque_part )
+    protected boolean _is_hier_part;
+    protected boolean _is_opaque_part;
+    // relativeURI   = ( net_path | abs_path | rel_path ) [ "?" query ] 
+    // hier_part     = ( net_path | abs_path ) [ "?" query ]
+    protected boolean _is_net_path;
+    protected boolean _is_abs_path;
+    protected boolean _is_rel_path;
+    // net_path      = "//" authority [ abs_path ] 
+    // authority     = server | reg_name
+    protected boolean _is_reg_name;
+    protected boolean _is_server;  // = _has_server
+    // server        = [ [ userinfo "@" ] hostport ]
+    // host          = hostname | IPv4address | IPv6reference
+    protected boolean _is_hostname;
+    protected boolean _is_IPv4address;
+    protected boolean _is_IPv6reference;
+
+    // ------------------------------------------ Character and escape encoding
+    
+    /**
+     * Encode with the default protocol charset.
+     *
+     * @param original the original character sequence
+     * @param allowed those characters that are allowed within a component
+     * @return URI character sequence
+     * @exception IOException null component or unsupported character encoding
+     */
+    protected static char[] encode(String original, BitSet allowed)
+        throws IOException {
+
+        return encode(original, allowed, _protocolCharset);
+    }
+
+
+    /**
+     * Encodes URI string.
+     *
+     * This is a two mapping, one from original characters to octets, and
+     * subsequently a second from octets to URI characters:
+     * <p><blockquote><pre>
+     *   original character sequence->octet sequence->URI character sequence
+     * </pre></blockquote><p>
+     *
+     * An escaped octet is encoded as a character triplet, consisting of the
+     * percent character "%" followed by the two hexadecimal digits
+     * representing the octet code. For example, "%20" is the escaped
+     * encoding for the US-ASCII space character.
+     * <p>
+     * Conversion from the local filesystem character set to UTF-8 will
+     * normally involve a two step process. First convert the local character
+     * set to the UCS; then convert the UCS to UTF-8.
+     * The first step in the process can be performed by maintaining a mapping
+     * table that includes the local character set code and the corresponding
+     * UCS code.
+     * The next step is to convert the UCS character code to the UTF-8 encoding.
+     * <p>
+     * Mapping between vendor codepages can be done in a very similar manner
+     * as described above.
+     * <p>
+     * The only time escape encodings can allowedly be made is when a URI is
+     * being created from its component parts.  The escape and validate methods
+     * are internally performed within this method.
+     *
+     * @param original the original character sequence
+     * @param allowed those characters that are allowed within a component
+     * @param charset the protocol charset
+     * @return URI character sequence
+     * @exception IOException null component or unsupported character encoding
+     */
+    protected static char[] encode(String original, BitSet allowed,
+            String charset) throws IOException {
+
+        // encode original to uri characters.
+        if (original == null) {
+            throw new IOException(/*IOException.PARSING,*/ "URI: null");
+        }
+        // escape octet to uri characters.
+        if (allowed == null) {
+            throw new IOException(/*IOException.PARSING,*/
+                    "URI: null allowed characters");
+        }
+        byte[] octets;
+        try {
+            octets = original.getBytes(charset);
+        } catch (UnsupportedEncodingException error) {
+            throw new IOException(/*IOException.UNSUPPORTED_ENCODING,*/ "Unsupported Encoding: " + charset);
+        }
+        StringBuffer buf = new StringBuffer(octets.length);
+        for (int i = 0; i < octets.length; i++) {
+            char c = (char) octets[i];
+            if (allowed.get(c)) {
+                buf.append(c);
+            } else {
+                buf.append('%');
+                byte b = octets[i]; // use the original byte value
+                char hexadecimal = Character.forDigit((b >> 4) & 0xF, 16);
+                buf.append(Character.toUpperCase(hexadecimal)); // high
+                hexadecimal = Character.forDigit(b & 0xF, 16);
+                buf.append(Character.toUpperCase(hexadecimal)); // low
+            }
+        }
+
+        return buf.toString().toCharArray();
+    }
+
+
+    /**
+     * Decode with the default protocol charset.
+     *
+     * @param component the URI character sequence
+     * @return original character sequence
+     * @exception IOException incomplete trailing escape pattern
+     * or unsupported character encoding
+     */
+    protected static String decode(char[] component) throws IOException {
+        return decode(component, _protocolCharset);
+    }
+
+
+    /**
+     * Decodes URI encoded string.
+     *
+     * This is a two mapping, one from URI characters to octets, and
+     * subsequently a second from octets to original characters:
+     * <p><blockquote><pre>
+     *   URI character sequence->octet sequence->original character sequence
+     * </pre></blockquote><p>
+     *
+     * A URI must be separated into its components before the escaped
+     * characters within those components can be allowedly decoded.
+     * <p>
+     * Notice that there is a chance that URI characters that are non UTF-8
+     * may be parsed as valid UTF-8.  A recent non-scientific analysis found
+     * that EUC encoded Japanese words had a 2.7% false reading; SJIS had a
+     * 0.0005% false reading; other encoding such as ASCII or KOI-8 have a 0%
+     * false reading.
+     * <p>
+     * The percent "%" character always has the reserved purpose of being
+     * the escape indicator, it must be escaped as "%25" in order to be used
+     * as data within a URI.
+     * <p>
+     * The unescape method is internally performed within this method.
+     *
+     * @param component the URI character sequence
+     * @param charset the protocol charset
+     * @return original character sequence
+     * @exception IOException incomplete trailing escape pattern
+     * or unsupported character encoding
+     */
+    protected static String decode(char[] component, String charset)
+        throws IOException {
+
+        // unescape uri characters to octets
+        if (component == null)  return null;
+
+        byte[] octets;
+        try {
+            octets = new String(component).getBytes(charset);
+        } catch (UnsupportedEncodingException error) {
+            throw new IOException(/* IOException.UNSUPPORTED_ENCODING, */
+                    "URI: not supported " + charset + " encoding");
+        }
+        int length = octets.length;
+        int oi = 0; // output index
+        for (int ii = 0; ii < length; oi++) {
+            byte aByte = (byte) octets[ii++];
+            if (aByte == '%' && ii+2 <= length)  {
+                byte high = (byte) Character.digit((char) octets[ii++], 16);
+                byte low = (byte) Character.digit((char) octets[ii++], 16);
+                if (high == -1 || low == -1) {
+                    throw new IOException(/* IOException.ESCAPING, */
+                            "URI: incomplete trailing escape pattern");
+                            
+                }
+                aByte = (byte) ((high << 4) + low);
+            }
+            octets[oi] = (byte) aByte;
+        }
+
+        String result;
+        try {
+            result = new String(octets, 0, oi, charset);
+        } catch (UnsupportedEncodingException error) {
+            throw new IOException(/* IOException.UNSUPPORTED_ENCODING, */
+                    "URI: not supported " + charset + " encoding");
+        }
+
+        return result;
+    }
+
+
+    /**
+     * Pre-validate the unescaped URI string within a specific component.
+     *
+     * @param component the component string within the component
+     * @param disallowed those characters disallowed within the component
+     * @return if true, it doesn't have the disallowed characters
+     * if false, the component is undefined or an incorrect one
+     */
+    protected boolean prevalidate(String component, BitSet disallowed) {
+        // prevalidate the given component by disallowed characters
+        if (component == null) {
+            return false; // undefined
+        }
+        char[] target = component.toCharArray();
+        for (int i = 0; i < target.length; i++) {
+            if (disallowed.get(target[i])) {
+                return false;
+            }
+        }
+        return true;
+    }
+
+
+    /**
+     * Validate the URI characters within a specific component.
+     * The component must be performed after escape encoding. Or it doesn't
+     * include escaped characters.
+     *
+     * @param component the characters sequence within the component
+     * @param generous those characters that are allowed within a component
+     * @return if true, it's the correct URI character sequence
+     */
+    protected boolean validate(char[] component, BitSet generous) {
+        // validate each component by generous characters
+        return validate(component, 0, -1, generous);
+    }
+
+
+    /**
+     * Validate the URI characters within a specific component.
+     * The component must be performed after escape encoding. Or it doesn't
+     * include escaped characters.
+     * <p>
+     * It's not that much strict, generous.  The strict validation might be 
+     * performed before being called this method.
+     *
+     * @param component the characters sequence within the component
+     * @param soffset the starting offset of the given component
+     * @param eoffset the ending offset of the given component
+     * if -1, it means the length of the component
+     * @param generous those characters that are allowed within a component
+     * @return if true, it's the correct URI character sequence
+     * @throws NullPointerException null component
+     */
+    protected boolean validate(char[] component, int soffset, int eoffset,
+            BitSet generous) {
+        // validate each component by generous characters
+        if (eoffset == -1) {
+            eoffset = component.length -1;
+        }
+        for (int i = soffset; i <= eoffset; i++) {
+            if (!generous.get(component[i])) return false;
+        }
+        return true;
+    }
+
+
+    /**
+     * In order to avoid any possilbity of conflict with non-ASCII characters,
+     * Parse a URI reference as a <code>String</code> with the character
+     * encoding of the local system or the document.
+     * <p>
+     * The following line is the regular expression for breaking-down a URI
+     * reference into its components.
+     * <p><blockquote><pre>
+     *   ^(([^:/?#]+):)?(//([^/?#]*))?([^?#]*)(\?([^#]*))?(#(.*))?
+     *    12            3  4          5       6  7        8 9
+     * </pre></blockquote><p>
+     * For example, matching the above expression to
+     *   http://jakarta.apache.org/ietf/uri/#Related
+     * results in the following subexpression matches:
+     * <p><blockquote><pre>
+     *               $1 = http:
+     *  scheme    =  $2 = http
+     *               $3 = //jakarta.apache.org
+     *  authority =  $4 = jakarta.apache.org
+     *  path      =  $5 = /ietf/uri/
+     *               $6 = <undefined>
+     *  query     =  $7 = <undefined>
+     *               $8 = #Related
+     *  fragment  =  $9 = Related
+     * </pre></blockquote><p>
+     *
+     * @param original the original character sequence
+     * @param escaped <code>true</code> if <code>original</code> is escaped
+     * @return the original character sequence
+     * @exception IOException
+     */
+    protected void parseUriReference(String original, boolean escaped)
+        throws IOException {
+
+        // validate and contruct the URI character sequence
+        if (original == null || original.length() == 0) {
+            throw new IOException("URI-Reference required");
+        }
+
+        /** @
+         *  ^(([^:/?#]+):)?(//([^/?#]*))?([^?#]*)(\?([^#]*))?(#(.*))?
+         */
+        String tmp = original.trim();
+        
+        /**
+         * The length of the string sequence of characters.
+         * It may not be equal to the length of the byte array.
+         */
+        int length = tmp.length();
+
+        /**
+         * Remove the delimiters like angle brackets around an URI.
+         */
+        char[] firstDelimiter = { tmp.charAt(0) };
+        if (validate(firstDelimiter, delims)) {
+            if (length >= 2) {
+                char[] lastDelimiter = { tmp.charAt(length - 1) };
+                if (validate(lastDelimiter, delims)) {
+                    tmp = tmp.substring(1, length - 1);
+                    length = length - 2;
+                }
+            }
+        }
+
+        /**
+         * The starting index
+         */
+        int from = 0;
+
+        /**
+         * The test flag whether the URI is started from the path component.
+         */
+        boolean isStartedFromPath = false;
+        int atColon = tmp.indexOf(':');
+        int atSlash = tmp.indexOf('/');
+        if (atColon < 0 || (atSlash >= 0 && atSlash < atColon)) {
+            isStartedFromPath = true;
+        }
+
+        /**
+         * <p><blockquote><pre>
+         *     @@@@@@@@
+         *  ^(([^:/?#]+):)?(//([^/?#]*))?([^?#]*)(\?([^#]*))?(#(.*))?
+         * </pre></blockquote><p>
+         */
+        int at = indexFirstOf(tmp, isStartedFromPath ? "/?#" : ":/?#", from);
+        if (at == -1) at = 0;
+
+        /**
+         * Parse the scheme.
+         * <p><blockquote><pre>
+         *  scheme    =  $2 = http
+         *              @
+         *  ^(([^:/?#]+):)?(//([^/?#]*))?([^?#]*)(\?([^#]*))?(#(.*))?
+         * </pre></blockquote><p>
+         */
+        if (at < length && tmp.charAt(at) == ':') {
+            char[] target = tmp.substring(0, at).toLowerCase().toCharArray();
+            if (validate(target, scheme)) {
+                _scheme = target;
+            } else {
+                throw new IOException("incorrect scheme");
+            }
+            from = ++at;
+        }
+
+        /**
+         * Parse the authority component.
+         * <p><blockquote><pre>
+         *  authority =  $4 = jakarta.apache.org
+         *                  @@
+         *  ^(([^:/?#]+):)?(//([^/?#]*))?([^?#]*)(\?([^#]*))?(#(.*))?
+         * </pre></blockquote><p>
+         */
+        // Reset flags
+        _is_net_path = _is_abs_path = _is_rel_path = _is_hier_part = false;
+        if (0 <= at && at < length && tmp.charAt(at) == '/') {
+            // Set flag
+            _is_hier_part = true;
+            if (at + 2 < length && tmp.charAt(at + 1) == '/') {
+                // the temporary index to start the search from
+                int next = indexFirstOf(tmp, "/?#", at + 2);
+                if (next == -1) {
+                    next = (tmp.substring(at + 2).length() == 0) ? at + 2 :
+                    tmp.length();
+                }
+                parseAuthority(tmp.substring(at + 2, next), escaped);
+                from = at = next;
+                // Set flag
+                _is_net_path = true;
+            }
+            if (from == at) {
+                // Set flag
+                _is_abs_path = true;
+            }
+        }
+
+        /**
+         * Parse the path component.
+         * <p><blockquote><pre>
+         *  path      =  $5 = /ietf/uri/
+         *                                @@@@@@
+         *  ^(([^:/?#]+):)?(//([^/?#]*))?([^?#]*)(\?([^#]*))?(#(.*))?
+         * </pre></blockquote><p>
+         */
+        if (from < length) {
+            // rel_path = rel_segment [ abs_path ]
+            int next = indexFirstOf(tmp, "?#", from);
+            if (next == -1) {
+                next = tmp.length();
+            }
+            if (!_is_abs_path) {
+                if (!escaped && prevalidate(tmp.substring(from, next),
+                            disallowed_rel_path) || escaped &&
+                        validate(tmp.substring(from, next).toCharArray(),
+                            rel_path)) {
+                    // Set flag
+                    _is_rel_path = true;
+                } else if (!escaped && prevalidate(tmp.substring(from, next),
+                            disallowed_opaque_part) || escaped &&
+                        validate(tmp.substring(from, next).toCharArray(),
+                            opaque_part)) {
+                    // Set flag
+                    _is_opaque_part = true;
+                } else {
+                    // the path component may be empty
+                    _path = null;
+                }
+            }
+            setPath(tmp.substring(from, next));
+            at = next;
+        }
+
+        /**
+         * Parse the query component.
+         * <p><blockquote><pre>
+         *  query     =  $7 = <undefined>
+         *                                        @@@@@@@@@
+         *  ^(([^:/?#]+):)?(//([^/?#]*))?([^?#]*)(\?([^#]*))?(#(.*))?
+         * </pre></blockquote><p>
+         */
+        if (0 <= at && at+1 < length && tmp.charAt(at) == '?') {
+            int next = tmp.indexOf('#', at + 1);
+            if (next == -1) {
+                next = tmp.length();
+            }
+            _query = (escaped) ? tmp.substring(at + 1, next).toCharArray() :
+            encode(tmp.substring(at + 1, next), allowed_query);
+            at = next;
+        }
+
+        /**
+         * Parse the fragment component.
+         * <p><blockquote><pre>
+         *  fragment  =  $9 = Related
+         *                                                   @@@@@@@@
+         *  ^(([^:/?#]+):)?(//([^/?#]*))?([^?#]*)(\?([^#]*))?(#(.*))?
+         * </pre></blockquote><p>
+         */
+        if (0 <= at && at+1 < length && tmp.charAt(at) == '#') {
+            _fragment = (escaped) ? tmp.substring(at + 1).toCharArray() :
+            encode(tmp.substring(at + 1), allowed_fragment);
+        }
+
+        // set this URI.
+        setUriReference();
+    }
+
+
+    /**
+     * Get the earlier index that to be searched for the first occurrance in
+     * one of any of the given string.
+     *
+     * @param s the string to be indexed
+     * @param delims the delimiters used to index
+     * @return the earlier index if there are delimiters
+     */
+    protected int indexFirstOf(String s, String delims) {
+        return indexFirstOf(s, delims, -1);
+    }
+
+
+    /**
+     * Get the earlier index that to be searched for the first occurrance in
+     * one of any of the given string.
+     *
+     * @param s the string to be indexed
+     * @param delims the delimiters used to index
+     * @param offset the from index
+     * @return the earlier index if there are delimiters
+     */
+    protected int indexFirstOf(String s, String delims, int offset) {
+        if (s == null || s.length() == 0) {
+            return -1;
+        }
+        if (delims == null || delims.length() == 0) {
+            return -1;
+        }
+        // check boundaries
+        if (offset < 0) {
+            offset = 0;
+        } else if (offset > s.length()) {
+            return -1;
+        }
+        // s is never null
+        int min = s.length();
+        char[] delim = delims.toCharArray();
+        for (int i = 0; i < delim.length; i++) {
+            int at = s.indexOf(delim[i], offset);
+            if (at >= 0 && at < min) {
+                min = at;
+            }
+        }
+        return (min == s.length()) ? -1 : min;
+    }
+
+
+    /**
+     * Get the earlier index that to be searched for the first occurrance in
+     * one of any of the given array.
+     *
+     * @param s the character array to be indexed
+     * @param delim the delimiter used to index
+     * @return the ealier index if there are a delimiter
+     */
+    protected int indexFirstOf(char[] s, char delim) {
+        return indexFirstOf(s, delim, 0);
+    }
+
+
+    /**
+     * Get the earlier index that to be searched for the first occurrance in
+     * one of any of the given array.
+     *
+     * @param s the character array to be indexed
+     * @param delim the delimiter used to index
+     * @return the ealier index if there is a delimiter
+     */
+    protected int indexFirstOf(char[] s, char delim, int offset) {
+        if (s == null || s.length == 0) {
+            return -1;
+        }
+        // check boundaries
+        if (offset < 0) {
+            offset = 0;
+        } else if (offset > s.length) {
+            return -1;
+        }
+        for (int i = offset; i < s.length; i++) {
+            if (s[i] == delim) {
+                return i;
+            }
+        }
+        return -1;
+    }
+
+
+    /**
+     * Parse the authority component.
+     *
+     * @param original the original character sequence of authority component
+     * @param escaped <code>true</code> if <code>original</code> is escaped
+     * @exception IOException
+     */
+    protected void parseAuthority(String original, boolean escaped)
+        throws IOException {
+
+        // Reset flags
+        _is_reg_name = _is_server =
+        _is_hostname = _is_IPv4address = _is_IPv6reference = false;
+
+        boolean has_port = true;
+        int from = 0;
+        int next = original.indexOf('@');
+        if (next != -1) { // neither -1 and 0
+            // each protocol extented from URI supports the specific userinfo
+            _userinfo = (escaped) ? original.substring(0, next).toCharArray() :
+            encode(original.substring(0, next), allowed_userinfo);
+            from = next + 1;
+        }
+        next = original.indexOf('[', from);
+        if (next >= from) {
+            next = original.indexOf(']', from);
+            if (next == -1) {
+                throw new IOException(/* IOException.PARSING,*/ "URI: IPv6reference");
+            } else {
+                next++;
+            }
+            // In IPv6reference, '[', ']' should be excluded
+            _host = (escaped) ? original.substring(from, next).toCharArray() :
+            encode(original.substring(from, next), allowed_IPv6reference);
+            // Set flag
+            _is_IPv6reference = true;
+        } else { // only for !_is_IPv6reference
+            next = original.indexOf(':', from);
+            if (next == -1) {
+                next = original.length();
+                has_port = false;
+            }
+            // REMINDME: it doesn't need the pre-validation
+            _host = original.substring(from, next).toCharArray();
+            if (validate(_host, IPv4address)) {
+                // Set flag
+                _is_IPv4address = true;
+            } else if (validate(_host, hostname)) {
+                // Set flag
+                _is_hostname = true;
+            } else {
+                // Set flag
+                _is_reg_name = true;
+            }
+        }
+        if (_is_reg_name) {
+            // Reset flags for a server-based naming authority
+            _is_server = _is_hostname = _is_IPv4address =
+            _is_IPv6reference = false;
+            // set a registry-based naming authority
+            _authority = (escaped) ? original.toString().toCharArray() :
+            encode(original.toString(), allowed_reg_name);
+        } else {
+            if (original.length()-1 > next && has_port &&
+                    original.charAt(next) == ':') { // not empty
+                from = next + 1;
+                try {
+                    _port = Integer.parseInt(original.substring(from));
+                } catch (NumberFormatException error) {
+                    throw new IOException(/*IOException.PARSING, */
+                            "URI: invalid port number");
+                }
+            }
+            // set a server-based naming authority
+            StringBuffer buf = new StringBuffer();
+            if (_userinfo != null) { // has_userinfo
+                buf.append(_userinfo);
+                buf.append('@');
+            }
+            if (_host != null) {
+                buf.append(_host);
+                if (_port != -1) {
+                    buf.append(':');
+                    buf.append(_port);
+                }
+            }
+            _authority = buf.toString().toCharArray();
+            // Set flag
+            _is_server = true;
+        }
+    }
+
+
+    /**
+     * Once it's parsed successfully, set this URI.
+     *
+     * @see #getRawURI
+     */
+    protected void setUriReference() {
+        // set _uri
+        StringBuffer buf = new StringBuffer();
+        // ^(([^:/?#]+):)?(//([^/?#]*))?([^?#]*)(\?([^#]*))?(#(.*))?
+        if (_scheme != null) {
+            buf.append(_scheme);
+            buf.append(':');
+        }
+        if (_is_net_path) {
+            buf.append("//");
+            if (_authority != null) { // has_authority
+                if (_userinfo != null) { // by default, remove userinfo part
+                    if (_host != null) {
+                        buf.append(_host);
+                        if (_port != -1) {
+                            buf.append(':');
+                            buf.append(_port);
+                        }
+                    }
+                } else {
+                    buf.append(_authority);
+                }
+            }
+        }
+        if (_opaque != null && _is_opaque_part) {
+            buf.append(_opaque);
+        } else if (_path != null) {
+            // _is_hier_part or _is_relativeURI
+            if (_path.length != 0) {
+                buf.append(_path);
+            }
+        }
+        if (_query != null) { // has_query
+            buf.append('?');
+            buf.append(_query);
+        }
+        if (_fragment != null) { // has_fragment
+            buf.append('#');
+            buf.append(_fragment);
+        }
+
+        _uri = buf.toString().toCharArray();
+    }
+
+    // ----------------------------------------------------------- Test methods
+  
+
+    /**
+     * Tell whether or not this URI is absolute.
+     *
+     * @return true iif this URI is absoluteURI
+     */
+    public boolean isAbsoluteURI() {
+        return (_scheme != null);
+    }
+  
+
+    /**
+     * Tell whether or not this URI is relative.
+     *
+     * @return true iif this URI is relativeURI
+     */
+    public boolean isRelativeURI() {
+        return (_scheme == null);
+    }
+
+
+    /**
+     * Tell whether or not the absoluteURI of this URI is hier_part.
+     *
+     * @return true iif the absoluteURI is hier_part
+     */
+    public boolean isHierPart() {
+        return _is_hier_part;
+    }
+
+
+    /**
+     * Tell whether or not the absoluteURI of this URI is opaque_part.
+     *
+     * @return true iif the absoluteURI is opaque_part
+     */
+    public boolean isOpaquePart() {
+        return _is_opaque_part;
+    }
+
+
+    /**
+     * Tell whether or not the relativeURI or heir_part of this URI is net_path.
+     * It's the same function as the has_authority() method.
+     *
+     * @return true iif the relativeURI or heir_part is net_path
+     * @see #hasAuthority
+     */
+    public boolean isNetPath() {
+        return _is_net_path || (_authority != null);
+    }
+
+
+    /**
+     * Tell whether or not the relativeURI or hier_part of this URI is abs_path.
+     *
+     * @return true iif the relativeURI or hier_part is abs_path
+     */
+    public boolean isAbsPath() {
+        return _is_abs_path;
+    }
+
+
+    /**
+     * Tell whether or not the relativeURI of this URI is rel_path.
+     *
+     * @return true iif the relativeURI is rel_path
+     */
+    public boolean isRelPath() {
+        return _is_rel_path;
+    }
+
+
+    /**
+     * Tell whether or not this URI has authority.
+     * It's the same function as the is_net_path() method.
+     *
+     * @return true iif this URI has authority
+     * @see #isNetPath
+     */
+    public boolean hasAuthority() {
+        return (_authority != null) || _is_net_path;
+    }
+
+    /**
+     * Tell whether or not the authority component of this URI is reg_name.
+     *
+     * @return true iif the authority component is reg_name
+     */
+    public boolean isRegName() {
+        return _is_reg_name;
+    }
+  
+
+    /**
+     * Tell whether or not the authority component of this URI is server.
+     *
+     * @return true iif the authority component is server
+     */
+    public boolean isServer() {
+        return _is_server;
+    }
+  
+
+    /**
+     * Tell whether or not this URI has userinfo.
+     *
+     * @return true iif this URI has userinfo
+     */
+    public boolean hasUserinfo() {
+        return (_userinfo != null);
+    }
+  
+
+    /**
+     * Tell whether or not the host part of this URI is hostname.
+     *
+     * @return true iif the host part is hostname
+     */
+    public boolean isHostname() {
+        return _is_hostname;
+    }
+
+
+    /**
+     * Tell whether or not the host part of this URI is IPv4address.
+     *
+     * @return true iif the host part is IPv4address
+     */
+    public boolean isIPv4address() {
+        return _is_IPv4address;
+    }
+
+
+    /**
+     * Tell whether or not the host part of this URI is IPv6reference.
+     *
+     * @return true iif the host part is IPv6reference
+     */
+    public boolean isIPv6reference() {
+        return _is_IPv6reference;
+    }
+
+
+    /**
+     * Tell whether or not this URI has query.
+     *
+     * @return true iif this URI has query
+     */
+    public boolean hasQuery() {
+        return (_query != null);
+    }
+   
+
+    /**
+     * Tell whether or not this URI has fragment.
+     *
+     * @return true iif this URI has fragment
+     */
+    public boolean hasFragment() {
+        return (_fragment != null);
+    }
+   
+   
+    // ---------------------------------------------------------------- Charset
+
+
+    /**
+     * Set the default charset of the protocol.
+     * <p>
+     * The character set used to store files SHALL remain a local decision and
+     * MAY depend on the capability of local operating systems. Prior to the
+     * exchange of URIs they SHOULD be converted into a ISO/IEC 10646 format
+     * and UTF-8 encoded. This approach, while allowing international exchange
+     * of URIs, will still allow backward compatibility with older systems
+     * because the code set positions for ASCII characters are identical to the
+     * one byte sequence in UTF-8.
+     * <p>
+     * An individual URI scheme may require a single charset, define a default
+     * charset, or provide a way to indicate the charset used.
+     *
+     * @param charset the default charset for each protocol
+     */
+    public static void setProtocolCharset(String charset) {
+        _protocolCharset = charset;
+    }
+
+
+    /**
+     * Get the default charset of the protocol.
+     * <p>
+     * An individual URI scheme may require a single charset, define a default
+     * charset, or provide a way to indicate the charset used.
+     * <p>
+     * To work globally either requires support of a number of character sets
+     * and to be able to convert between them, or the use of a single preferred
+     * character set.
+     * For support of global compatibility it is STRONGLY RECOMMENDED that
+     * clients and servers use UTF-8 encoding when exchanging URIs.
+     *
+     * @return the charset string
+     */
+    public static String getProtocolCharset() {
+        return _protocolCharset;
+    }
+
+
+    /**
+     * Set the default charset of the document.
+     * <p>
+     * Notice that it will be possible to contain mixed characters (e.g.
+     * ftp://host/KoreanNamespace/ChineseResource). To handle the Bi-directional
+     * display of these character sets, the protocol charset could be simply
+     * used again. Because it's not yet implemented that the insertion of BIDI
+     * control characters at different points during composition is extracted.
+     *
+     * @param charset the default charset for the document
+     */
+    public static void setDocumentCharset(String charset) {
+        _documentCharset = charset;
+    }
+
+
+    /**
+     * Get the default charset of the document.
+     *
+     * @return the charset string
+     */
+    public static String getDocumentCharset() {
+        return _documentCharset;
+    }
+
+    // ------------------------------------------------------------- The scheme
+
+    /**
+     * Get the scheme.
+     *
+     * @return the scheme
+     */
+    public char[] getRawScheme() {
+        return _scheme;
+    }
+
+
+    /**
+     * Get the scheme.
+     *
+     * @return the scheme
+     * null if undefined scheme
+     */
+    public String getScheme() {
+        return (_scheme == null) ? null : new String(_scheme);
+    }
+
+    // ---------------------------------------------------------- The authority
+
+    /**
+     * Set the authority.  It can be one type of server, hostport, hostname,
+     * IPv4address, IPv6reference and reg_name.
+     * <p><blockquote><pre>
+     *   authority     = server | reg_name
+     * </pre></blockquote><p>
+     *
+     * @param escapedAuthority the raw escaped authority
+     * @exception IOException
+     * @throws NullPointerException null authority
+     */
+    public void setRawAuthority(char[] escapedAuthority) throws IOException {
+        parseAuthority(new String(escapedAuthority), true);
+        setUriReference();
+    }
+
+
+    /**
+     * Set the authority.  It can be one type of server, hostport, hostname,
+     * IPv4address, IPv6reference and reg_name.
+     * Note that there is no setAuthority method by the escape encoding reason.
+     *
+     * @param escapedAuthority the escaped authority string
+     * @exception IOException
+     */
+    public void setEscapedAuthority(String escapedAuthority)
+        throws IOException {
+
+        parseAuthority(escapedAuthority, true);
+        setUriReference();
+    }
+
+
+    /**
+     * Get the raw-escaped authority.
+     *
+     * @return the raw-escaped authority
+     */
+    public char[] getRawAuthority() {
+        return _authority;
+    }
+
+
+    /**
+     * Get the escaped authority.
+     *
+     * @return the escaped authority
+     */
+    public String getEscapedAuthority() {
+        return (_authority == null) ? null : new String(_authority);
+    }
+
+
+    /**
+     * Get the authority.
+     *
+     * @return the authority
+     * @exception IOException
+     * @see #decode
+     */
+    public String getAuthority() throws IOException {
+        return (_authority == null) ? null : decode(_authority);
+    }
+
+    // ----------------------------------------------------------- The userinfo
+
+    /**
+     * Get the raw-escaped userinfo.
+     *
+     * @return the raw-escaped userinfo
+     * @see #getAuthority
+     */
+    public char[] getRawUserinfo() {
+        return _userinfo;
+    }
+
+
+    /**
+     * Get the escaped userinfo.
+     *
+     * @return the escaped userinfo
+     * @see #getAuthority
+     */
+    public String getEscapedUserinfo() {
+        return (_userinfo == null) ? null : new String(_userinfo);
+    }
+
+
+    /**
+     * Get the userinfo.
+     *
+     * @return the userinfo
+     * @exception IOException
+     * @see #decode
+     * @see #getAuthority
+     */
+    public String getUserinfo() throws IOException {
+        return (_userinfo == null) ? null : decode(_userinfo);
+    }
+
+    // --------------------------------------------------------------- The host
+
+    /**
+     * Get the host.
+     * <p><blockquote><pre>
+     *   host          = hostname | IPv4address | IPv6reference
+     * </pre></blockquote><p>
+     *
+     * @return the host
+     * @see #getAuthority
+     */
+    public char[] getRawHost() {
+        return _host;
+    }
+
+
+    /**
+     * Get the host.
+     * <p><blockquote><pre>
+     *   host          = hostname | IPv4address | IPv6reference
+     * </pre></blockquote><p>
+     *
+     * @return the host
+     * @exception IOException
+     * @see #decode
+     * @see #getAuthority
+     */
+    public String getHost() throws IOException {
+        return decode(_host);
+    }
+
+    // --------------------------------------------------------------- The port
+
+    /**
+     * Get the port.  In order to get the specfic default port, the specific
+     * protocol-supported class extended from the URI class should be used.
+     * It has the server-based naming authority.
+     *
+     * @return the port
+     * if -1, it has the default port for the scheme or the server-based
+     * naming authority is not supported in the specific URI.
+     */
+    public int getPort() {
+        return _port;
+    }
+
+    // --------------------------------------------------------------- The path
+
+    /**
+     * Set the path.   The method couldn't be used by API programmers.
+     *
+     * @param path the path string
+     * @exception IOException set incorrectly or fragment only
+     * @see #encode
+     */
+    protected void setPath(String path) throws IOException {
+
+        // set path
+        if (_is_net_path || _is_abs_path) {
+            _path = encode(path, allowed_abs_path);
+        } else if (_is_rel_path) {
+            StringBuffer buff = new StringBuffer(path.length());
+            int at = path.indexOf('/');
+            if (at > 0) {  // never 0
+                buff.append(encode(path.substring(0, at), allowed_rel_path));
+                buff.append(encode(path.substring(at), allowed_abs_path));
+            } else {
+                buff.append(encode(path, allowed_rel_path));
+            }
+            _path = buff.toString().toCharArray();
+        } else if (_is_opaque_part) {
+            _opaque = encode(path, allowed_opaque_part);
+        } else {
+            throw new IOException(/*IOException.PARSING, */"URI: incorrect path");
+        }
+    }
+
+
+    /**
+     * Resolve the base and relative path.
+     *
+     * @param base_path a character array of the base_path
+     * @param rel_path a character array of the rel_path
+     * @return the resolved path
+     */
+    protected char[] resolvePath(char[] base_path, char[] rel_path) {
+
+        // REMINDME: paths are never null
+        String base = (base_path == null) ? "" : new String(base_path);
+        int at = base.lastIndexOf('/');
+        if (at != -1) {
+            base_path = base.substring(0, at + 1).toCharArray();
+        }
+        // _path could be empty
+        if (rel_path == null || rel_path.length == 0) {
+            return normalize(base_path);
+        } else if (rel_path[0] == '/') {
+            return rel_path;
+        } else {
+            StringBuffer buff = new StringBuffer(base.length() +
+                rel_path.length);
+            if (at != -1) {
+                buff.append(base.substring(0, at + 1));
+                buff.append(rel_path);
+            }
+            return normalize(buff.toString().toCharArray());
+        }
+    }
+
+
+    /**
+     * Get the raw-escaped current hierarchy level in the given path.
+     * If the last namespace is a collection, the slash mark ('/') should be
+     * ended with at the last character of the path string.
+     *
+     * @param path the path
+     * @return the current hierarchy level
+     * @exception IOException no hierarchy level
+     */
+    protected char[] getRawCurrentHierPath(char[] path) throws IOException {
+
+        if (_is_opaque_part) {
+            throw new IOException(/*IOException.PARSING,*/ "URI: no hierarchy level");
+        }
+        if (path == null) {
+            throw new IOException(/*IOException.PARSING,*/ "URI: emtpy path");
+        }
+        String buff = new String(path);
+        int first = buff.indexOf('/');
+        int last = buff.lastIndexOf('/');
+        if (last == 0) {
+            return rootPath;
+        } else if (first != last && last != -1) {
+            return buff.substring(0, last).toCharArray();
+        }
+        // FIXME: it could be a document on the server side
+        return path;
+    }
+
+
+    /**
+     * Get the raw-escaped current hierarchy level.
+     *
+     * @return the raw-escaped current hierarchy level
+     * @exception IOException no hierarchy level
+     */
+    public char[] getRawCurrentHierPath() throws IOException {
+        return (_path == null) ? null : getRawCurrentHierPath(_path);
+    }
+ 
+
+    /**
+     * Get the escaped current hierarchy level.
+     *
+     * @return the escaped current hierarchy level
+     * @exception IOException no hierarchy level
+     */
+    public String getEscapedCurrentHierPath() throws IOException {
+        char[] path = getRawCurrentHierPath();
+        return (path == null) ? null : new String(path);
+    }
+ 
+
+    /**
+     * Get the current hierarchy level.
+     *
+     * @return the current hierarchy level
+     * @exception IOException
+     * @see #decode
+     */
+    public String getCurrentHierPath() throws IOException {
+        char[] path = getRawCurrentHierPath();
+        return (path == null) ? null : decode(path);
+    }
+
+
+    /**
+     * Get the level above the this hierarchy level.
+     *
+     * @return the raw above hierarchy level
+     * @exception IOException
+     */
+    public char[] getRawAboveHierPath() throws IOException {
+        char[] path = getRawCurrentHierPath();
+        return (path == null) ? null : getRawCurrentHierPath(path);
+    }
+
+
+    /**
+     * Get the level above the this hierarchy level.
+     *
+     * @return the raw above hierarchy level
+     * @exception IOException
+     */
+    public String getEscapedAboveHierPath() throws IOException {
+        char[] path = getRawAboveHierPath();
+        return (path == null) ? null : new String(path);
+    }
+
+
+    /**
+     * Get the level above the this hierarchy level.
+     *
+     * @return the above hierarchy level
+     * @exception IOException
+     * @see #decode
+     */
+    public String getAboveHierPath() throws IOException {
+        char[] path = getRawAboveHierPath();
+        return (path == null) ? null : decode(path);
+    }
+
+
+    /**
+     * Get the raw-escaped path.
+     * <p><blockquote><pre>
+     *   path          = [ abs_path | opaque_part ]
+     * </pre></blockquote><p>
+     *
+     * @return the raw-escaped path
+     */
+    public char[] getRawPath() {
+        return _is_opaque_part ? _opaque : _path;
+    }
+
+
+    /**
+     * Get the escaped path.
+     * <p><blockquote><pre>
+     *   path          = [ abs_path | opaque_part ]
+     *   abs_path      = "/"  path_segments 
+     *   opaque_part   = uric_no_slash *uric
+     * </pre></blockquote><p>
+     *
+     * @return the escaped path string
+     */
+    public String getEscapedPath() {
+        char[] path = getRawPath();
+        return (path == null) ? null : new String(path);
+    }
+
+
+    /**
+     * Get the path.
+     * <p><blockquote><pre>
+     *   path          = [ abs_path | opaque_part ]
+     * </pre></blockquote><p>
+     * @return the path string
+     * @exception IOException
+     * @see #decode
+     */
+    public String getPath() throws IOException { 
+        char[] path =  getRawPath();
+        return (path == null) ? null : decode(path);
+    }
+
+
+    /**
+     * Get the raw-escaped basename of the path.
+     *
+     * @return the raw-escaped basename
+     */
+    public char[] getRawName() {
+        if (_path == null) return null;
+
+        int at = 0;
+        for (int i = _path.length - 1; i >= 0; i--) {
+            if (_path[i] == '/') {
+                at = i + 1;
+                break;
+            }
+        }
+        int len = _path.length - at;
+        char[] basename =  new char[len];
+        System.arraycopy(_path, at, basename, 0, len);
+        return basename;
+    }
+
+
+    /**
+     * Get the escaped basename of the path.
+     *
+     * @return the escaped basename string
+     */
+    public String getEscapedName() {
+        char[] basename = getRawName();
+        return (basename == null) ? null : new String(basename);
+    }
+
+
+    /**
+     * Get the basename of the path.
+     *
+     * @return the basename string
+     * @exception IOException incomplete trailing escape pattern
+     * Or unsupported character encoding
+     * @see #decode
+     */
+    public String getName() throws IOException {
+        char[] basename = getRawName();
+        return (basename == null) ? null : decode(getRawName());
+    }
+
+    // ----------------------------------------------------- The path and query 
+
+    /**
+     * Get the raw-escaped path and query.
+     *
+     * @return the raw-escaped path and query
+     */
+    public char[] getRawPathQuery() {
+
+        if (_path == null && _query == null) {
+            return null;
+        }
+        StringBuffer buff = new StringBuffer();
+        if (_path != null) {
+            buff.append(_path);
+        }
+        if (_query != null) {
+            buff.append('?');
+            buff.append(_query);
+        }
+        return buff.toString().toCharArray();
+    }
+
+
+    /**
+     * Get the escaped query.
+     *
+     * @return the escaped path and query string
+     */
+    public String getEscapedPathQuery() {
+        char[] rawPathQuery = getRawPathQuery();
+        return (rawPathQuery == null) ? null : new String(rawPathQuery);
+    }
+
+
+    /**
+     * Get the path and query.
+     *
+     * @return the path and query string.
+     * @exception IOException incomplete trailing escape pattern
+     * Or unsupported character encoding
+     * @see #decode
+     */
+    public String getPathQuery() throws IOException {
+        char[] rawPathQuery = getRawPathQuery();
+        return (rawPathQuery == null) ? null : decode(rawPathQuery);
+    }
+
+    // -------------------------------------------------------------- The query 
+
+    /**
+     * Set the raw-escaped query.
+     *
+     * @param escapedQuery the raw-escaped query
+     * @exception IOException escaped query not valid
+     * @throws NullPointerException null query
+     */
+    public void setRawQuery(char[] escapedQuery) throws IOException {
+        if (!validate(escapedQuery, query))
+            throw new IOException(/*IOException.ESCAPING,*/
+                    "URI: escaped query not valid");
+        _query = escapedQuery;
+        setUriReference();
+    }
+
+
+    /**
+     * Set the escaped query string.
+     *
+     * @param escapedQuery the escaped query string
+     * @exception IOException escaped query not valid
+     * @throws NullPointerException null query
+     */
+    public void setEscapedQuery(String escapedQuery) throws IOException {
+        setRawQuery(escapedQuery.toCharArray());
+    }
+
+
+    /**
+     * Set the query.
+     * When a query string is not misunderstood the reserved special characters
+     * ("&amp;", "=", "+", ",", and "$") within a query component, it is
+     * recommended to use in encoding the whole query with this method.
+     *
+     * @param query the query string.
+     * @exception IOException incomplete trailing escape pattern
+     * Or unsupported character encoding
+     * @throws NullPointerException null query
+     * @see #encode
+     */
+    public void setQuery(String query) throws IOException {
+        setRawQuery(encode(query, allowed_query));
+    }
+
+
+    /**
+     * Get the raw-escaped query.
+     *
+     * @return the raw-escaped query
+     */
+    public char[] getRawQuery() {
+        return _query;
+    }
+
+
+    /**
+     * Get the escaped query.
+     *
+     * @return the escaped query string
+     */
+    public String getEscapedQuery() {
+        return (_query == null) ? null : new String(_query);
+    }
+
+
+    /**
+     * Get the query.
+     *
+     * @return the query string.
+     * @exception IOException incomplete trailing escape pattern
+     * Or unsupported character encoding
+     * @see #decode
+     */
+    public String getQuery() throws IOException {
+        return (_query == null) ? null : decode(_query);
+    }
+
+    // ----------------------------------------------------------- The fragment 
+
+    /**
+     * Set the raw-escaped fragment.
+     *
+     * @param escapedFragment the raw-escaped fragment
+     * @exception IOException escaped fragment not valid
+     * @throws NullPointerException null fragment
+     */
+    public void setRawFragment(char[] escapedFragment) throws IOException {
+        if (!validate(escapedFragment, fragment))
+            throw new IOException(/*IOException.ESCAPING,*/
+                    "URI: escaped fragment not valid");
+        _fragment = escapedFragment;
+        setUriReference();
+    }
+
+
+    /**
+     * Set the escaped fragment string.
+     *
+     * @param escapedFragment the escaped fragment string
+     * @exception IOException escaped fragment not valid
+     * @throws NullPointerException null fragment
+     */
+    public void setEscapedFragment(String escapedFragment) throws IOException {
+        char[] fragmentSequence = escapedFragment.toCharArray();
+        if (!validate(fragmentSequence, fragment))
+            throw new IOException(/*IOException.ESCAPING,*/
+                    "URI: escaped fragment not valid");
+        _fragment = fragmentSequence;
+        setUriReference();
+    }
+
+
+    /**
+     * Set the fragment.
+     *
+     * @param the fragment string.
+     * @exception IOException
+     * Or unsupported character encoding
+     * @throws NullPointerException null fragment
+     */
+    public void setFragment(String fragment) throws IOException {
+        _fragment = encode(fragment, allowed_fragment);
+        setUriReference();
+    }
+
+
+    /**
+     * Get the raw-escaped fragment.
+     * <p>
+     * The optional fragment identifier is not part of a URI, but is often used
+     * in conjunction with a URI.
+     * <p>
+     * The format and interpretation of fragment identifiers is dependent on
+     * the media type [RFC2046] of the retrieval result.
+     * <p>
+     * A fragment identifier is only meaningful when a URI reference is
+     * intended for retrieval and the result of that retrieval is a document
+     * for which the identified fragment is consistently defined.
+     *
+     * @return the raw-escaped fragment
+     */
+    public char[] getRawFragment() {
+        return _fragment;
+    }
+
+
+    /**
+     * Get the escaped fragment.
+     *
+     * @return the escaped fragment string
+     */
+    public String getEscapedFragment() {
+        return (_fragment == null) ? null : new String(_fragment);
+    }
+
+
+    /**
+     * Get the fragment.
+     *
+     * @return the fragment string
+     * @exception IOException incomplete trailing escape pattern
+     * Or unsupported character encoding
+     * @see #decode
+     */
+    public String getFragment() throws IOException {
+        return (_fragment == null) ? null : decode(_fragment);
+    }
+
+    // ------------------------------------------------------------- Utilities 
+
+    /**
+     * Normalize the given hier path part.
+     *
+     * @param path the path to normalize
+     * @return the normalized path
+     */
+    protected char[] normalize(char[] path) {
+
+        if (path == null) return null;
+
+        String normalized = new String(path);
+        boolean endsWithSlash = true;
+        // precondition
+        if (!normalized.endsWith("/")) {
+            normalized += '/';
+            endsWithSlash = false;
+        }
+        if (normalized.endsWith("/./") || normalized.endsWith("/../")) {
+            endsWithSlash = true;
+        }
+        // Resolve occurrences of "/./" in the normalized path
+        while (true) {
+            int at = normalized.indexOf("/./");
+            if (at == -1) {
+                break;
+            }
+            normalized = normalized.substring(0, at) +
+            normalized.substring(at + 2);
+        }
+        // Resolve occurrences of "/../" in the normalized path
+        while (true) {
+            int at = normalized.indexOf("/../");
+            if (at == -1) {
+                break;
+            }
+            if (at == 0) {
+                normalized = "/";
+                break;
+            }
+            int backward = normalized.lastIndexOf('/', at - 1);
+            if (backward == -1) {
+                // consider the rel_path
+                normalized = normalized.substring(at + 4);
+            } else {
+                normalized = normalized.substring(0, backward) +
+                normalized.substring(at + 3);
+            }
+        }
+        // Resolve occurrences of "//" in the normalized path
+        while (true) {
+            int at = normalized.indexOf("//");
+            if (at == -1) {
+                break;
+            }
+            normalized = normalized.substring(0, at) +
+            normalized.substring(at + 1);
+        }
+        if (!endsWithSlash && normalized.endsWith("/")) {
+            normalized = normalized.substring(0, normalized.length()-1);
+        } else if (endsWithSlash && !normalized.endsWith("/")) {
+            normalized = normalized + "/";
+        }
+        // Set the normalized path that we have completed
+        return normalized.toCharArray();
+    }
+
+
+    /**
+     * Normalize the path part of this URI.
+     */
+    public void normalize() {
+        _path = normalize(_path);
+    }
+
+
+    /**
+     * Test if the first array is equal to the second array.
+     *
+     * @param first the first character array
+     * @param second the second character array
+     * @return true if they're equal
+     */
+    protected boolean equals(char[] first, char[] second) {
+
+        if (first == null && second == null) {
+            return true;
+        }
+        if (first == null || second == null) {
+            return false;
+        }
+        if (first.length != second.length) {
+            return false;
+        }
+        for (int i = 0; i < first.length; i++) {
+            if (first[i] != second[i]) {
+                return false;
+            }
+        }
+        return true;
+    }
+
+
+    /**
+     * Test an object if this URI is equal to another.
+     *
+     * @param obj an object to compare
+     * @return true if two URI objects are equal
+     */
+    public boolean equals(Object obj) {
+
+        // normalize and test each components
+        if (obj == this) {
+            return true;
+        }
+        if (!(obj instanceof URI)) {
+            return false;
+        }
+        URI another = (URI) obj;
+        // scheme
+        if (!equals(_scheme, another._scheme)) {
+            return false;
+        }
+        // is_opaque_part or is_hier_part?  and opaque
+        if (!equals(_opaque, another._opaque)) {
+            return false;
+        }
+        // is_hier_part
+        // has_authority
+        if (!equals(_authority, another._authority)) {
+            return false;
+        }
+        // path
+        if (!equals(_path, another._path)) {
+            return false;
+        }
+        // has_query
+        if (!equals(_query, another._query)) {
+            return false;
+        }
+        // has_fragment?  should be careful of the only fragment case.
+        if (!equals(_fragment, another._fragment)) {
+            return false;
+        }
+        return true;
+    }
+
+    // ---------------------------------------------------------- Serialization
+
+    /**
+     * Write the content of this URI.
+     *
+     * @param oos the object-output stream
+     */
+    protected void writeObject(java.io.ObjectOutputStream oos)
+        throws IOException {
+
+        oos.defaultWriteObject();
+    }
+
+
+    /**
+     * Read a URI.
+     *
+     * @param ois the object-input stream
+     */
+    protected void readObject(java.io.ObjectInputStream ois)
+        throws ClassNotFoundException, IOException {
+
+        ois.defaultReadObject();
+    }
+
+    // ------------------------------------------------------------- Comparison 
+
+    /**
+     * Compare this URI to another object. 
+     *
+     * @param obj the object to be compared.
+     * @return 0, if it's same,
+     * -1, if failed, first being compared with in the authority component
+     * @exception ClassCastException not URI argument
+     * @throws NullPointerException null object
+     */
+    public int compareTo(Object obj) {
+
+        URI another = (URI) obj;
+        if (!equals(_authority, another.getRawAuthority())) return -1;
+        return toString().compareTo(another.toString());
+    }
+
+    // ------------------------------------------------------------------ Clone
+
+    /**
+     * Create and return a copy of this object, the URI-reference containing
+     * the userinfo component.  Notice that the whole URI-reference including
+     * the userinfo component counld not be gotten as a <code>String</code>.
+     * <p>
+     * To copy the identical <code>URI</code> object including the userinfo
+     * component, it should be used.
+     *
+     * @return a clone of this instance
+     */
+    public synchronized Object clone() {
+
+        URI instance = new URI();
+
+        instance._uri = _uri;
+        instance._scheme = _scheme;
+        instance._opaque = _opaque;
+        instance._authority = _authority;
+        instance._userinfo = _userinfo;
+        instance._host = _host;
+        instance._port = _port;
+        instance._path = _path;
+        instance._query = _query;
+        instance._fragment = _fragment;
+        // flags
+        instance._is_hier_part = _is_hier_part;
+        instance._is_opaque_part = _is_opaque_part;
+        instance._is_net_path = _is_net_path;
+        instance._is_abs_path = _is_abs_path;
+        instance._is_rel_path = _is_rel_path;
+        instance._is_reg_name = _is_reg_name;
+        instance._is_server = _is_server;
+        instance._is_hostname = _is_hostname;
+        instance._is_IPv4address = _is_IPv4address;
+        instance._is_IPv6reference = _is_IPv6reference;
+
+        return instance;
+    }
+
+    // ------------------------------------------------------------ Get the URI
+
+    /**
+     * It can be gotten the URI character sequence. It's raw-escaped.
+     * For the purpose of the protocol to be transported, it will be useful.
+     * <p>
+     * It is clearly unwise to use a URL that contains a password which is
+     * intended to be secret. In particular, the use of a password within
+     * the 'userinfo' component of a URL is strongly disrecommended except
+     * in those rare cases where the 'password' parameter is intended to be
+     * public.
+     * <p>
+     * When you want to get each part of the userinfo, you need to use the
+     * specific methods in the specific URL. It depends on the specific URL.
+     *
+     * @return URI character sequence
+     */
+    public char[] getRawURI() {
+        return _uri;
+    }
+
+
+    /**
+     * It can be gotten the URI character sequence. It's escaped.
+     * For the purpose of the protocol to be transported, it will be useful.
+     *
+     * @return the URI string
+     */
+    public String getEscapedURI() {
+        return (_uri == null) ? null : new String(_uri);
+    }
+    
+
+    /**
+     * It can be gotten the URI character sequence.
+     *
+     * @return the URI string
+     * @exception IOException incomplete trailing escape pattern
+     * Or unsupported character encoding
+     * @see #decode
+     */
+    public String getURI() throws IOException {
+        return (_uri == null) ? null : decode(_uri);
+    }
+
+
+    /**
+     * Get the escaped URI string.
+     * <p>
+     * On the document, the URI-reference form is only used without the userinfo
+     * component like http://jakarta.apache.org/ by the security reason.
+     * But the URI-reference form with the userinfo component could be parsed.
+     * <p>
+     * In other words, this URI and any its subclasses must not expose the
+     * URI-reference expression with the userinfo component like
+     * http://user:password@hostport/restricted_zone.<br>
+     * It means that the API client programmer should extract each user and
+     * password to access manually.  Probably it will be supported in the each
+     * subclass, however, not a whole URI-reference expression.
+     *
+     * @return the URI string
+     * @see #clone()
+     */
+    public String toString() {
+        return getEscapedURI();
+    }
+
+
+    // ------------------------------------------------------------ Inner class
+
+    /** 
+     * A mapping to determine the (somewhat arbitrarily) preferred charset for 
+     * a given locale.  Supports all locales recognized in JDK 1.1.
+     * <p>
+     * The distribution of this class is Servlets.com.    It was originally
+     * written by Jason Hunter [jhunter at acm.org] and used by with permission.
+     */
+    public static class LocaleToCharsetMap {
+
+        private static Hashtable map;
+        static {
+            map = new Hashtable();
+            map.put("ar", "ISO-8859-6");
+            map.put("be", "ISO-8859-5");
+            map.put("bg", "ISO-8859-5");
+            map.put("ca", "ISO-8859-1");
+            map.put("cs", "ISO-8859-2");
+            map.put("da", "ISO-8859-1");
+            map.put("de", "ISO-8859-1");
+            map.put("el", "ISO-8859-7");
+            map.put("en", "ISO-8859-1");
+            map.put("es", "ISO-8859-1");
+            map.put("et", "ISO-8859-1");
+            map.put("fi", "ISO-8859-1");
+            map.put("fr", "ISO-8859-1");
+            map.put("hr", "ISO-8859-2");
+            map.put("hu", "ISO-8859-2");
+            map.put("is", "ISO-8859-1");
+            map.put("it", "ISO-8859-1");
+            map.put("iw", "ISO-8859-8");
+            map.put("ja", "Shift_JIS");
+            map.put("ko", "EUC-KR");
+            map.put("lt", "ISO-8859-2");
+            map.put("lv", "ISO-8859-2");
+            map.put("mk", "ISO-8859-5");
+            map.put("nl", "ISO-8859-1");
+            map.put("no", "ISO-8859-1");
+            map.put("pl", "ISO-8859-2");
+            map.put("pt", "ISO-8859-1");
+            map.put("ro", "ISO-8859-2");
+            map.put("ru", "ISO-8859-5");
+            map.put("sh", "ISO-8859-5");
+            map.put("sk", "ISO-8859-2");
+            map.put("sl", "ISO-8859-2");
+            map.put("sq", "ISO-8859-2");
+            map.put("sr", "ISO-8859-5");
+            map.put("sv", "ISO-8859-1");
+            map.put("tr", "ISO-8859-9");
+            map.put("uk", "ISO-8859-5");
+            map.put("zh", "GB2312");
+            map.put("zh_TW", "Big5");
+        }
+       
+        /**
+         * Get the preferred charset for the given locale.
+         *
+         * @param locale the locale
+         * @return the preferred charset
+         * or null if the locale is not recognized
+         */
+        public static String getCharset(Locale locale) {
+            // try for an full name match (may include country)
+            String charset = (String) map.get(locale.toString());
+            if (charset != null) return charset;
+           
+            // if a full name didn't match, try just the language
+            charset = (String) map.get(locale.getLanguage());
+            return charset;  // may be null
+        }
+
+    }
+
+}
+