browserlauncher.java

九宫问题（八数码）的一个小软件

                    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) {
                        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";
                try {
                    if (new File("/usr/bin/mozilla").exists())
                        browser = "/usr/bin/mozilla";
                } catch (Exception e) {
                    // ignore
                }
                break;
        }
        return browser;
    }
    
    
    public static void openURL(URL url) throws IOException {
        openURL(url.toExternalForm());
    }
    /**
     * 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 + '"' });
                
//VW opens browser without first displaying the distracting command window
// TODO: test quotes, for some reason I recall it does not work in this case
                Process process = Runtime.getRuntime().exec("rundll32 url.dll,FileProtocolHandler " + url);
                
                // This avoids a memory leak on some versions of Java on Windows.
                // That's hinted at in <http://developer.java.sun.com/developer/qow/archive/68/>.
                try {
                    process.waitFor();
                    process.exitValue();
                } catch (InterruptedException ie) {
                    throw new IOException("InterruptedException while launching browser: " + ie.getMessage());
                }
                break;
            case OTHER:
                // Assume that we're on Unix and that Netscape is installed
                
                // First, attempt to open the URL in a currently running session of Netscape
                process = Runtime.getRuntime().exec(new String[] { (String) browser,
                NETSCAPE_REMOTE_PARAMETER,
                NETSCAPE_OPEN_PARAMETER_START +
                        url +
                        NETSCAPE_OPEN_PARAMETER_END });
                try {
                    int exitCode = process.waitFor();
                    if (exitCode != 0) {	// if Netscape was not open
                        Runtime.getRuntime().exec(new String[] { (String) browser, url });
                    }
                } catch (InterruptedException ie) {
                    throw new IOException("InterruptedException while launching browser: " + ie.getMessage());
                }
                break;
            default:
                // This should never occur, but if it does, we'll try the simplest thing possible
                Runtime.getRuntime().exec(new String[] { (String) browser, url });
                break;
        }
    }
    
    /**
     * Methods required for Mac OS X.  The presence of native methods does not cause
     * any problems on other platforms.
     */
    private native static int ICStart(int[] instance, int signature);
    private native static int ICStop(int[] instance);
    private native static int ICLaunchURL(int instance, byte[] hint, byte[] data, int len,
            int[] selectionStart, int[] selectionEnd);
}