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+/*
+ * Copyright © 2003-2009 Israfil Consulting Services Corporation
+ * Copyright © 2003-2009 Christian Edward Gruber
+ * All Rights Reserved
+ *
+ * This software is licensed under the Berkeley Standard Distribution license,
+ * (BSD license), as defined below:
+ *
+ * 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. Neither the name of Israfil Consulting Services nor the names of its contributors
+ * may be used to endorse or promote products derived from this software without
+ * specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ * ANY EXPRESS 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 COPYRIGHT OWNER OR 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.
+ *
+ * $Id: DynamicallyAccessibleObject.java 76 2006-08-03 15:37:05Z cgruber $
+ */
+package net.israfil.foundation.dynamic;
+
+import java.util.logging.Level;
+import java.util.logging.Logger;
+
+import net.israfil.foundation.core.Strings;
+
+/**
+ * An implementation of the DynamicallyAccessible interface with the
+ * appropriate infrastructure for retrieving field data, via accessors if
+ * such are implemented, or directly from the field where not.
+ *
+ * @author <a href="mailto:cgruber@israfil.net">Christian Edward Gruber </a>
+ * @author Latest: $Author: cgruber $
+ * @version $Revision: 76 $
+ */
+public abstract class DynamicallyAccessibleObject extends DynamicObject implements DynamicallyAccessible {
+ private static Logger logger = Logger.getLogger(DynamicallyAccessibleObject.class.getName());
+
+ public Object get(String attributeName) {
+ return get(this,attributeName);
+ }
+
+ public static Object get(Object receiver, String attributeName) {
+ try {
+ return _get(receiver, attributeName);
+ } catch (NoSuchFieldException e) {
+ logger.log(Level.FINE,"Object attempted to dynamically access a non-existant or unreadable field.",e);
+ throw new RuntimeException(e);
+ } catch (IllegalAccessException e) {
+ logger.log(Level.FINE,"Object attempted to dynamically access a inaccessible field.",e);
+ throw new RuntimeException(e);
+ }
+ }
+
+ /** @deprecated This method is deprecated in favour of the static _get(receiver, attributeName) */
+ Object _get(String attributeName) throws NoSuchFieldException, IllegalAccessException {
+ return _get(this,attributeName);
+ }
+
+ /**
+ * Internal _get method that throws all the exceptions, to be wrapped by public methods
+ * so that the various exceptions can be given meaning in different contexts (such
+ * as fetching data, vs. testing for the existance of something.
+ *
+ * @param attributeName
+ * @return
+ * @throws NoSuchFieldException
+ * @throws IllegalAccessException
+ */
+ static Object _get(Object receiver, String attributeName) throws NoSuchFieldException, IllegalAccessException {
+ if (hasAccessor(receiver,attributeName)) return DynamicUtil.performOn(receiver,_getAccessorSelector(receiver,attributeName), new Object[]{});
+ return receiver.getClass().getField(attributeName).get(receiver);
+ }
+
+ /**
+ * Determines whether an attribute of the given name exists on this object's
+ * definition, or if not, if there is a javabeans-style accessor named
+ * appropriately for that attribute. Put another way, determines whether
+ * a get() call would work against this attribute name.
+ *
+ * The existing implementation is inefficient, but simple to maintain.
+ */
+ public boolean hasAttribute(String attributeName) {
+ return hasAttribute(this,attributeName);
+ }
+
+ public static boolean hasAttribute(Object receiver, String attributeName) {
+ try {
+ _get(receiver,attributeName);
+ return true;
+ } catch (NoSuchFieldException e) {
+ logger.log(Level.FINEST,"Object attempted to dynamically access a non-existant or unreadable field.",e);
+ return false;
+ } catch (IllegalAccessException e) {
+ logger.log(Level.FINEST,"Object attempted to dynamically access a inaccessible field.",e);
+ return false;
+ }
+ }
+
+ protected static final String[] accessPrefixes = new String[] { "get","is" };
+
+ /** @deprecated This method is deprecated in favour of the static _getAccessorSelector(receiver,attribute) */
+ protected String getAccessorSelector(String attributeName) { return _getAccessorSelector(this,attributeName); }
+
+ protected static String _getAccessorSelector(Object receiver, String attributeName) {
+ if (attributeName == null || attributeName.equals("")) return null;
+ String camelAttr = camel(attributeName);
+ for (String prefix : accessPrefixes) {
+ String selector = prefix+camelAttr;
+ if (DynamicUtil.respondsTo(receiver,selector)) return selector;
+ }
+ // No accessor, try a NeXTSTEP-style accessor, named the same as the property.
+ if (DynamicUtil.respondsTo(receiver,attributeName)) return attributeName;
+ return null;
+ }
+
+ public boolean hasAccessor(String attributeName) {
+ return hasAccessor(this,attributeName);
+ }
+
+ public static boolean hasAccessor(Object receiver, String attributeName) {
+ return _getAccessorSelector(receiver,attributeName) != null;
+ }
+
+ /** @deprecated This method has been moved to net.israfil.foundation.core.Strings.camel(String) */
+ public static String camel(String string) {
+ return Strings.camel(string);
+ }
+
+}