+ * 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:
+ *
Steven Spencer, JavaWorld magazine (Java Tip 66)
+ *
Thanks also to Ron B. Yeh, Eric Shapiro, Ben Engber, Paul Teitlebaum, Andrea Cantatore,
+ * Larry Barowski, Trevor Bedzek, Frank Miedrich, and Ron Rabakukk
+ *
+ * @author Eric Albert (ejalbert@cs.stanford.edu)
+ * @version 1.4b1 (Released June 20, 2001)
+ */
+public class EjAlbertBrowserLauncher {
+
+ /**
+ * The Java virtual machine that we are running on. Actually, in most cases we only care
+ * about the operating system, but some operating systems require us to switch on the VM. */
+ private static int jvm;
+
+ /** The browser for the system */
+ private static Object browser;
+
+ /**
+ * Caches whether any classes, methods, and fields that are not part of the JDK and need to
+ * be dynamically loaded at runtime loaded successfully.
+ *
+ * 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[] { EjAlbertBrowserLauncher.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) {
+ 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:
+ case WINDOWS_9x:
+ // 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