BrowserLauncher is a class that provides one static method, * openURL, which opens the default web browser for the current user * of the system to the given URL. It may support other protocols * depending on the system -- mailto, ftp, etc. -- but that has not * been rigorously tested and is not guaranteed to work.
* *Yes, this is platform-specific code, and yes, it may rely on * classes on certain platforms that are not part of the standard JDK. * What we're trying to do, though, is to take something that's * frequently desirable but inherently platform-specific -- opening a * default browser -- and allow programmers (you, for example) to do * so without worrying about dropping into native code or doing * anything else similarly evil.
* *Anyway, this code is completely in Java and will run on all JDK * 1.1-compliant systems without modification or a need for additional * libraries. All classes that are required on certain platforms to * allow this to run are dynamically loaded at runtime via reflection * and, if not found, will not cause this to do anything other than * returning an error when opening the browser.
* *There are certain system requirements for this class, as it's * running through Runtime.exec(), which is Java's way of making a * native system call. Currently, this requires that a Macintosh have * a Finder which supports the GURL event, which is true for Mac OS * 8.0 and 8.1 systems that have the Internet Scripting AppleScript * dictionary installed in the Scripting Additions folder in the * Extensions folder (which is installed by default as far as I know * under Mac OS 8.0 and 8.1), and for all Mac OS 8.5 and later * systems. On Windows, it only runs under Win32 systems (Windows 95, * 98, and NT 4.0, as well as later versions of all). On other * systems, this drops back from the inherently platform-sensitive * concept of a default browser and simply attempts to launch Netscape * via a shell command.
* *This code is Copyright 1999-2001 by Eric Albert * (ejalbert@cs.stanford.edu) and may be redistributed or modified in * any form without restrictions as long as the portion of this * comment from this paragraph through the end of the comment is not * removed. The author requests that he be notified of any * application, applet, or other binary that makes use of this code, * but that's more out of curiosity than anything and is not required. * This software includes no warranty. The author is not repsonsible * for any loss of data or functionality or any adverse or unexpected * effects of using this software.
* * Credits: Note that if this is
* false, openURL() will always return
* an IOException. */
private static boolean loadedWithoutErrors;
/** The com.apple.mrj.MRJFileUtils class */
private static Class mrjFileUtilsClass;
/** The com.apple.mrj.MRJOSType class */
private static Class mrjOSTypeClass;
/** The com.apple.MacOS.AEDesc class */
private static Class aeDescClass;
/** The true if all intialization succeeded
* false if any portion of the initialization failed */
private static boolean loadClasses() {
switch (jvm) {
case MRJ_2_0:
try {
Class aeTargetClass = Class.forName("com.apple.MacOS.AETarget");
Class osUtilsClass = Class.forName("com.apple.MacOS.OSUtils");
Class appleEventClass = Class.forName
("com.apple.MacOS.AppleEvent");
Class aeClass = Class.forName("com.apple.MacOS.ae");
aeDescClass = Class.forName("com.apple.MacOS.AEDesc");
aeTargetConstructor = aeTargetClass.getDeclaredConstructor
(new Class [] { int.class });
appleEventConstructor = appleEventClass.getDeclaredConstructor
(new Class[] { int.class, int.class, aeTargetClass,
int.class, int.class });
aeDescConstructor = aeDescClass.getDeclaredConstructor
(new Class[] { String.class });
makeOSType = osUtilsClass.getDeclaredMethod
("makeOSType", new Class [] { String.class });
putParameter = appleEventClass.getDeclaredMethod
("putParameter", new Class[] { int.class, aeDescClass });
sendNoReply = appleEventClass.getDeclaredMethod
("sendNoReply", new Class[] { });
Field keyDirectObjectField = aeClass.getDeclaredField
("keyDirectObject");
keyDirectObject = (Integer) keyDirectObjectField.get(null);
Field autoGenerateReturnIDField = appleEventClass
.getDeclaredField("kAutoGenerateReturnID");
kAutoGenerateReturnID = (Integer) autoGenerateReturnIDField
.get(null);
Field anyTransactionIDField = appleEventClass.getDeclaredField
("kAnyTransactionID");
kAnyTransactionID = (Integer) anyTransactionIDField.get(null);
} catch (ClassNotFoundException cnfe) {
errorMessage = cnfe.getMessage();
return false;
} catch (NoSuchMethodException nsme) {
errorMessage = nsme.getMessage();
return false;
} catch (NoSuchFieldException nsfe) {
errorMessage = nsfe.getMessage();
return false;
} catch (IllegalAccessException iae) {
errorMessage = iae.getMessage();
return false;
}
break;
case MRJ_2_1:
try {
mrjFileUtilsClass = Class.forName("com.apple.mrj.MRJFileUtils");
mrjOSTypeClass = Class.forName("com.apple.mrj.MRJOSType");
Field systemFolderField = mrjFileUtilsClass.getDeclaredField
("kSystemFolderType");
kSystemFolderType = systemFolderField.get(null);
findFolder = mrjFileUtilsClass.getDeclaredMethod
("findFolder", new Class[] { mrjOSTypeClass });
getFileCreator = mrjFileUtilsClass.getDeclaredMethod
("getFileCreator", new Class[] { File.class });
getFileType = mrjFileUtilsClass.getDeclaredMethod
("getFileType", new Class[] { File.class });
} catch (ClassNotFoundException cnfe) {
errorMessage = cnfe.getMessage();
return false;
} catch (NoSuchFieldException nsfe) {
errorMessage = nsfe.getMessage();
return false;
} catch (NoSuchMethodException nsme) {
errorMessage = nsme.getMessage();
return false;
} catch (SecurityException se) {
errorMessage = se.getMessage();
return false;
} catch (IllegalAccessException iae) {
errorMessage = iae.getMessage();
return false;
}
break;
case MRJ_3_0:
try {
Class linker = Class.forName("com.apple.mrj.jdirect.Linker");
Constructor constructor = linker.getConstructor
(new Class[]{ Class.class });
linkage = constructor.newInstance(new Object[]
{ BrowserLauncher.class });
} catch (ClassNotFoundException cnfe) {
errorMessage = cnfe.getMessage();
return false;
} catch (NoSuchMethodException nsme) {
errorMessage = nsme.getMessage();
return false;
} catch (InvocationTargetException ite) {
errorMessage = ite.getMessage();
return false;
} catch (InstantiationException ie) {
errorMessage = ie.getMessage();
return false;
} catch (IllegalAccessException iae) {
errorMessage = iae.getMessage();
return false;
}
break;
case MRJ_3_1:
try {
mrjFileUtilsClass = Class.forName("com.apple.mrj.MRJFileUtils");
openURL = mrjFileUtilsClass.getDeclaredMethod
("openURL", new Class[] { String.class });
} catch (ClassNotFoundException cnfe) {
errorMessage = cnfe.getMessage();
return false;
} catch (NoSuchMethodException nsme) {
errorMessage = nsme.getMessage();
return false;
}
break;
default:
break;
}
return true;
}
/** Attempts to locate the default web browser on the local
* system. Caches results so it only locates the browser once *
* for each use of this class per JVM instance.
* @return The browser for the system. Note that this may not be
* what you would consider to be a standard web browser; instead,
* it's the application that gets called to open the default web
* browser. In some cases, this will be a non-String object that
* provides the means of calling the default browser. */
private static Object locateBrowser() {
if (browser != null) {
return browser;
}
switch (jvm) {
case MRJ_2_0:
try {
Integer finderCreatorCode = (Integer) makeOSType.invoke
(null, new Object[] { FINDER_CREATOR });
Object aeTarget = aeTargetConstructor.newInstance
(new Object[] { finderCreatorCode });
Integer gurlType = (Integer) makeOSType.invoke
(null, new Object[] { GURL_EVENT });
Object appleEvent = appleEventConstructor.newInstance
(new Object[] { gurlType, gurlType, aeTarget,
kAutoGenerateReturnID, kAnyTransactionID });
// Don't set browser = appleEvent because then the
// next time we call locateBrowser(), we'll get the
// same AppleEvent, to which we'll already have added
// the relevant parameter. Instead, regenerate the
// AppleEvent every time. There's probably a way to
// do this better; if any has any ideas, please let me
// know.
return appleEvent;
} catch (IllegalAccessException iae) {
browser = null;
errorMessage = iae.getMessage();
return browser;
} catch (InstantiationException ie) {
browser = null;
errorMessage = ie.getMessage();
return browser;
} catch (InvocationTargetException ite) {
browser = null;
errorMessage = ite.getMessage();
return browser;
}
case MRJ_2_1:
File systemFolder;
try {
systemFolder = (File) findFolder.invoke(null, new Object[]
{ kSystemFolderType });
} catch (IllegalArgumentException iare) {
browser = null;
errorMessage = iare.getMessage();
return browser;
} catch (IllegalAccessException iae) {
browser = null;
errorMessage = iae.getMessage();
return browser;
} catch (InvocationTargetException ite) {
browser = null;
errorMessage = ite.getTargetException().getClass() + ": " +
ite.getTargetException().getMessage();
return browser;
}
String[] systemFolderFiles = systemFolder.list();
// Avoid a FilenameFilter because that can't be stopped mid-list
for(int i = 0; i < systemFolderFiles.length; i++) {
try {
File file = new File(systemFolder, systemFolderFiles[i]);
if (!file.isFile()) {
continue;
}
// We're looking for a file with a creator code of
// 'MACS' and a type of 'FNDR'. Only requiring
// the type results in non-Finder applications
// being picked up on certain Mac OS 9 systems,
// especially German ones, and sending a GURL
// event to those applications results in a logout
// under Multiple Users.
Object fileType = getFileType.invoke
(null, new Object[] { file });
if (FINDER_TYPE.equals(fileType.toString())) {
Object fileCreator = getFileCreator.invoke
(null, new Object[] { file });
if (FINDER_CREATOR.equals(fileCreator.toString())) {
browser = file.toString(); // Actually the
// Finder, but that's OK
return browser;
}
}
} catch (IllegalArgumentException iare) {
//WTF? browser = browser;
errorMessage = iare.getMessage();
return null;
} catch (IllegalAccessException iae) {
browser = null;
errorMessage = iae.getMessage();
return browser;
} catch (InvocationTargetException ite) {
browser = null;
errorMessage = ite.getTargetException().getClass() + ": "
+ ite.getTargetException().getMessage();
return browser;
}
}
browser = null;
break;
case MRJ_3_0:
case MRJ_3_1:
browser = ""; // Return something non-null
break;
case WINDOWS_NT:
browser = "cmd.exe";
break;
case WINDOWS_9x:
browser = "command.com";
break;
case OTHER:
default:
browser = "netscape";
break;
}
return browser;
}
/** Attempts to open the default web browser to the given URL.
* @param url The URL to open
* @throws IOException If the web browser could not be located or
* does not run */
public static void openURL(String url) throws IOException {
if (!loadedWithoutErrors) {
throw new IOException("Exception in finding browser: "
+ errorMessage);
}
Object browser = locateBrowser();
if (browser == null) {
throw new IOException("Unable to locate browser: " + errorMessage);
}
switch (jvm) {
case MRJ_2_0:
Object aeDesc = null;
try {
aeDesc = aeDescConstructor.newInstance(new Object[] { url });
putParameter.invoke(browser, new Object[]
{ keyDirectObject, aeDesc });
sendNoReply.invoke(browser, new Object[] { });
} catch (InvocationTargetException ite) {
throw new IOException("InvocationTargetException while creating"
+" AEDesc: " + ite.getMessage());
} catch (IllegalAccessException iae) {
throw new IOException("IllegalAccessException while building "
+ "AppleEvent: " + iae.getMessage());
} catch (InstantiationException ie) {
throw new IOException("InstantiationException while creating "
+ "AEDesc: " + ie.getMessage());
} finally {
aeDesc = null; // Encourage it to get disposed if it
// was created
browser = null; // Ditto
}
break;
case MRJ_2_1:
Runtime.getRuntime().exec(new String[] { (String) browser, url } );
break;
case MRJ_3_0:
int[] instance = new int[1];
int result = ICStart(instance, 0);
if (result == 0) {
int[] selectionStart = new int[] { 0 };
byte[] urlBytes = url.getBytes();
int[] selectionEnd = new int[] { urlBytes.length };
result = ICLaunchURL(instance[0], new byte[] { 0 }, urlBytes,
urlBytes.length, selectionStart,
selectionEnd);
if (result == 0) {
// Ignore the return value; the URL was launched
// successfully regardless of what happens here.
ICStop(instance);
} else {
throw new IOException("Unable to launch URL: " + result);
}
} else {
throw new IOException("Unable to create an Internet Config "
+ "instance: " + result);
}
break;
case MRJ_3_1:
try {
openURL.invoke(null, new Object[] { url });
} catch (InvocationTargetException ite) {
throw new IOException("InvocationTargetException while calling "
+ "openURL: " + ite.getMessage());
} catch (IllegalAccessException iae) {
throw new IOException("IllegalAccessException while calling "
+ "openURL: " + iae.getMessage());
}
break;
case WINDOWS_NT:
// Add quotes around the URL to allow ampersands and other special
// characters to work.
Process process = Runtime.getRuntime().exec(new String[]
{ (String) browser, FIRST_WINDOWS_PARAMETER,
SECOND_WINDOWS_PARAMETER, THIRD_WINDOWS_PARAMETER,
'"' + url + '"' });
// This avoids a memory leak on some versions of Java on
// Windows. That's hinted at in
//