fxts.stations.util.BrowserLauncher.java Source code

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/*
 * Copyright 2006 FXCM LLC
 *
 * 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 fxts.stations.util;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

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 java.net.URL;

/**
 * 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:
 * <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 default system browser under windows.
    private static final String WIN_PATH = "rundll32";
    // The flag to display a url.
    private static final String WIN_FLAG = "url.dll,FileProtocolHandler";
    /**
     * 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 <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;

    /**
     * This class should be never be instantiated; this just ensures so.
     */
    private BrowserLauncher() {
    }

    private static native int ICLaunchURL(int instance, byte[] hint, byte[] data, int len, int[] selectionStart,
            int[] selectionEnd);

    /**
     * Methods required for Mac OS X.  The presence of native methods does not cause
     * any problems on other platforms.
     */
    private static native int ICStart(int[] instance, int signature);

    private static native int ICStop(int[] instance);

    /**
     * Returns BasicService class.
     */
    private static Class getBasicServiceClass() {
        try {
            return Class.forName("javax.jnlp.BasicService");
        } catch (Exception ex) {
            return null;
        }
    }

    /**
     * Returns BasicService object.
     */
    private static Object getBasicServiceObject() {
        Class serviceManagerClass;
        Method lookupMethod;
        try {
            serviceManagerClass = Class.forName("javax.jnlp.ServiceManager");
            lookupMethod = serviceManagerClass.getMethod("lookup", new Class[] { String.class });
            return lookupMethod.invoke(null, new Object[] { "javax.jnlp.BasicService" });
        } catch (Exception ex) {
            return null;
        }
    }

    /**
     * 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:
            // cmd = 'rundll32 url.dll,FileProtocolHandler http://...'
            Process process = Runtime.getRuntime().exec(WIN_PATH + " " + WIN_FLAG + " " + 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;
        }
    }

    // + 4/27/2004 USHIK +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

    /**
     * This method open url at default browser by using JNLP.
     * If JNLP not available (start of application not trought Java WebStart)
     * the its return false.
     */
    public static boolean showDocument(String sUrl) {
        Boolean resultBoolean;
        Class basicServiceClass;
        Object basicServiceObject;
        Method method;
        URL url;

        //gets BasicService class
        basicServiceClass = getBasicServiceClass();
        //gets BasicService object
        basicServiceObject = getBasicServiceObject();
        if (basicServiceClass == null || basicServiceObject == null) {
            return false;
        }
        try {
            url = new URL(sUrl);
        } catch (Exception ex) {
            ex.printStackTrace();
            return false;
        }
        try {
            method = basicServiceClass.getMethod("showDocument", new Class[] { URL.class });
            //invokes BasicService`s method
            resultBoolean = (Boolean) method.invoke(basicServiceObject, new Object[] { url });
            return resultBoolean.booleanValue();
        } catch (Exception ex) {
            ex.printStackTrace();
            return false;
        }
    }

    // + 4/27/2004 USHIK END ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
    /**
     * 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();
        }
    }
}