/TaxonDNA/com/ggvaidya/TaxonDNA/Others/BrowserLauncher.java

package com.ggvaidya.TaxonDNA.Others;



/* All code after this line entirely the creation and (c) Eric Albert, 1999-2001. Used as per conditions. */



import java.io.File;

import java.io.FileNotFoundException;

import java.io.IOException;

import java.lang.reflect.Constructor;

import java.lang.reflect.Field;

import java.lang.reflect.InvocationTargetException;

import java.lang.reflect.Method;



/**

 * 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>

 * 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>

 * 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>

 * 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);

}