/src/java/org/jivesoftware/openfire/launcher/BrowserLauncher.java

/**

 * $RCSfile$

 * $Revision: 128 $

 * $Date: 2004-10-25 20:42:00 -0300 (Mon, 25 Oct 2004) $

 *

 * Copyright (C) 2004-2008 Jive Software. All rights reserved.

 *

 * Licensed under the Apache License, Version 2.0 (the "License");

 * you may not use this file except in compliance with the License.

 * You may obtain a copy of the License at

 *

 *     http://www.apache.org/licenses/LICENSE-2.0

 *

 * Unless required by applicable law or agreed to in writing, software

 * distributed under the License is distributed on an "AS IS" BASIS,

 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

 * See the License for the specific language governing permissions and

 * limitations under the License.

 */



package org.jivesoftware.openfire.launcher;



import java.io.File;

import java.io.IOException;

import java.lang.reflect.Constructor;

import java.lang.reflect.Field;

import java.lang.reflect.InvocationTargetException;

import java.lang.reflect.Method;



import org.slf4j.Logger;

import org.slf4j.LoggerFactory;



/**

 * 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.

 * <p>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.

 * </p>

 * <p>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.

 * </p>

 * <p>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.

 * </p>

 * <p>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.

 * </p>

 * Credits:

 * <br>Steven Spencer, JavaWorld magazine (<a href="http://www.javaworld.com/javaworld/javatips/jw-javatip66.html">Java Tip 66</a>)

 * <br>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 (<a href="mailto:ejalbert@cs.stanford.edu">ejalbert@cs.stanford.edu</a>)

 * @version 1.4b1 (Released June 20, 2001)

 */

public class BrowserLauncher {



    /**

     * 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.

     * <p/>

     * Note that if this is <code>false</code>, <code>openURL()</code> 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 <init>(int) method of com.apple.MacOS.AETarget

     */

    private static Constructor aeTargetConstructor;



    /**

     * The <init>(int, int, int) method of com.apple.MacOS.AppleEvent

     */

    private static Constructor appleEventConstructor;



    /**

     * The <init>(String) method of com.apple.MacOS.AEDesc

     */

    private static Constructor aeDescConstructor;



    /**

     * The findFolder method of com.apple.mrj.MRJFileUtils

     */

    private static Method findFolder;



    /**

     * The getFileCreator method of com.apple.mrj.MRJFileUtils

     */

    private static Method getFileCreator;



    /**

     * The getFileType method of com.apple.mrj.MRJFileUtils

     */

    private static Method getFileType;



    /**

     * The openURL method of com.apple.mrj.MRJFileUtils

     */

    private static Method openURL;



    /**

     * The makeOSType method of com.apple.MacOS.OSUtils

     */

    private static Method makeOSType;



    /**

     * The putParameter method of com.apple.MacOS.AppleEvent

     */

    private static Method putParameter;



    /**

     * The sendNoReply method of com.apple.MacOS.AppleEvent

     */

    private static Method sendNoReply;



    /**

     * Actually an MRJOSType pointing to the System Folder on a Macintosh

     */

    private static Object kSystemFolderType;



    /**

     * The keyDirectObject AppleEvent parameter type

     */

    private static Integer keyDirectObject;



    /**

     * The kAutoGenerateReturnID AppleEvent code

     */

    private static Integer kAutoGenerateReturnID;



    /**

     * The kAnyTransactionID AppleEvent code

     */

    private static Integer kAnyTransactionID;



    /**

     * The linkage object required for JDirect 3 on Mac OS X.

     */

    private static Object linkage;



    /**

     * The framework to reference on Mac OS X

     */

    private static final String JDirect_MacOSX = "/System/Library/Frameworks/Carbon.framework/Frameworks/HIToolbox.framework/HIToolbox";



    /**

     * JVM constant for MRJ 2.0

     */

    private static final int MRJ_2_0 = 0;



    /**

     * JVM constant for MRJ 2.1 or later

     */

    private static final int MRJ_2_1 = 1;



    /**

     * JVM constant for Java on Mac OS X 10.0 (MRJ 3.0)

     */

    private static final int MRJ_3_0 = 3;



    /**

     * JVM constant for MRJ 3.1

     */

    private static final int MRJ_3_1 = 4;



    /**

     * JVM constant for any Windows NT JVM

     */

    private static final int WINDOWS_NT = 5;



    /**

     * JVM constant for any Windows 9x JVM

     */

    private static final int WINDOWS_9x = 6;



    /**

     * JVM constant for any other platform

     */

    private static final int OTHER = -1;



    /**

     * The file type of the Finder on a Macintosh.  Hardcoding "Finder" would keep non-U.S. English

     * systems from working properly.

     */

    private static final String FINDER_TYPE = "FNDR";



    /**

     * The creator code of the Finder on a Macintosh, which is needed to send AppleEvents to the

     * application.

     */

    private static final String FINDER_CREATOR = "MACS";



    /**

     * The name for the AppleEvent type corresponding to a GetURL event.

     */

    private static final String GURL_EVENT = "GURL";



    /**

     * The first parameter that needs to be passed into Runtime.exec() to open the default web

     * browser on Windows.

     */

    private static final String FIRST_WINDOWS_PARAMETER = "/c";



    /**

     * The second parameter for Runtime.exec() on Windows.

     */

    private static final String SECOND_WINDOWS_PARAMETER = "start";



    /**

     * The third parameter for Runtime.exec() on Windows.  This is a "title"

     * parameter that the command line expects.  Setting this parameter allows

     * URLs containing spaces to work.

     */

    private static final String THIRD_WINDOWS_PARAMETER = "\"\"";



    /**

     * The shell parameters for Netscape that opens a given URL in an already-open copy of Netscape

     * on many command-line systems.

     */

    private static final String NETSCAPE_REMOTE_PARAMETER = "-remote";

    private static final String NETSCAPE_OPEN_PARAMETER_START = "'openURL(";

    private static final String NETSCAPE_OPEN_PARAMETER_END = ")'";



    /**

     * The message from any exception thrown throughout the initialization process.

     */

    private static String errorMessage;



    /**

     * An initialization block that determines the operating system and loads the necessary

     * runtime data.

     */

    static {

        loadedWithoutErrors = true;

        String osName = System.getProperty("os.name");

        if (osName.startsWith("Mac OS")) {

            String mrjVersion = System.getProperty("mrj.version");

            String majorMRJVersion = mrjVersion.substring(0, 3);

            try {

                double version = Double.valueOf(majorMRJVersion).doubleValue();

                if (version == 2) {

                    jvm = MRJ_2_0;

                }

                else if (version >= 2.1 && version < 3) {

                    // Assume that all 2.x versions of MRJ work the same.  MRJ 2.1 actually

                    // works via Runtime.exec() and 2.2 supports that but has an openURL() method

                    // as well that we currently ignore.

                    jvm = MRJ_2_1;

                }

                else if (version == 3.0) {

                    jvm = MRJ_3_0;

                }

                else if (version >= 3.1) {

                    // Assume that all 3.1 and later versions of MRJ work the same.

                    jvm = MRJ_3_1;

                }

                else {

                    loadedWithoutErrors = false;

                    errorMessage = "Unsupported MRJ version: " + version;

                }

            }

            catch (NumberFormatException nfe) {

                loadedWithoutErrors = false;

                errorMessage = "Invalid MRJ version: " + mrjVersion;

            }

        }

        else if (osName.startsWith("Windows")) {

            if (osName.indexOf("9") != -1) {

                jvm = WINDOWS_9x;

            }

            else {

                jvm = WINDOWS_NT;

            }

        }

        else {

            jvm = OTHER;

        }



        if (loadedWithoutErrors) {	// if we haven't hit any errors yet

            loadedWithoutErrors = loadClasses();

        }

    }



    /**

     * This class should be never be instantiated; this just ensures so.

     */

    private BrowserLauncher() {

    }



    /**

     * Called by a static initializer to load any classes, fields, and methods required at runtime

     * to locate the user's web browser.

     *

     * @return <code>true</code> if all intialization succeeded

     *         <code>false</code> 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) {

                        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 <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);

}