// Copyright (C) 2001-2003 Jon A. Maxwell (JAM) // // This library is free software; you can redistribute it and/or // modify it under the terms of the GNU Lesser General Public // License as published by the Free Software Foundation; either // version 2.1 of the License, or (at your option) any later version. // // This library is distributed in the hope that it will be useful, // but WITHOUT ANY WARRANTY; without even the implied warranty of // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU // Lesser General Public License for more details. // // You should have received a copy of the GNU Lesser General Public // License along with this library; if not, write to the Free Software // Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. package net.sourceforge.jnlp; import static net.sourceforge.jnlp.runtime.Translator.R; import java.applet.Applet; import java.awt.Container; import java.io.File; import java.io.FileInputStream; import java.io.FileOutputStream; import java.io.IOException; import java.lang.management.ManagementFactory; import java.lang.management.ThreadMXBean; import java.lang.reflect.Method; import java.net.InetAddress; import java.net.URL; import java.net.UnknownHostException; import java.nio.channels.FileChannel; import java.nio.channels.FileLock; import java.util.LinkedList; import java.util.List; import java.util.jar.JarFile; import net.sourceforge.jnlp.cache.CacheUtil; import net.sourceforge.jnlp.cache.ResourceTracker; import net.sourceforge.jnlp.cache.UpdatePolicy; import net.sourceforge.jnlp.config.DeploymentConfiguration; import net.sourceforge.jnlp.runtime.AppThreadGroup; import net.sourceforge.jnlp.runtime.AppletInstance; import net.sourceforge.jnlp.runtime.ApplicationInstance; import net.sourceforge.jnlp.runtime.JNLPClassLoader; import net.sourceforge.jnlp.runtime.JNLPRuntime; import net.sourceforge.jnlp.services.InstanceExistsException; import net.sourceforge.jnlp.services.ServiceUtil; import net.sourceforge.jnlp.util.FileUtils; import net.sourceforge.jnlp.util.Reflect; import javax.swing.SwingUtilities; import javax.swing.text.html.parser.ParserDelegator; import sun.awt.SunToolkit; /** * Launches JNLPFiles either in the foreground or background.

* * An optional LaunchHandler can be specified that is notified of * warning and error condition while launching and that indicates * whether a launch may proceed after a warning has occurred. If * specified, the LaunchHandler is notified regardless of whether * the file is launched in the foreground or background.

* * @author Jon A. Maxwell (JAM) - initial author * @version $Revision: 1.22 $ */ public class Launcher { // defines class Launcher.BgRunner, Launcher.TgThread /** shared thread group */ /*package*/static final ThreadGroup mainGroup = new ThreadGroup(R("LAllThreadGroup")); /** the handler */ private LaunchHandler handler = null; /** the update policy */ private UpdatePolicy updatePolicy = JNLPRuntime.getDefaultUpdatePolicy(); /** whether to create an AppContext (if possible) */ private boolean context = true; /** If the application should call System.exit on fatal errors */ private boolean exitOnFailure = true; /** a lock which is held to indicate that an instance of netx is running */ private FileLock fileLock; /** * Create a launcher with the runtime's default update policy * and launch handler. */ public Launcher() { this(null, null); if (handler == null) handler = JNLPRuntime.getDefaultLaunchHandler(); } /** * Create a launcher with the runtime's default update policy * and launch handler. * * @param exitOnFailure Exit if there is an error (usually default, but false when being used from the plugin) */ public Launcher(boolean exitOnFailure) { this(null, null); if (handler == null) handler = JNLPRuntime.getDefaultLaunchHandler(); this.exitOnFailure = exitOnFailure; } /** * Create a launcher with the specified handler and the * runtime's default update policy. * * @param handler the handler to use or null for no handler. */ public Launcher(LaunchHandler handler) { this(handler, null); } /** * Create a launcher with an optional handler using the * specified update policy and launch handler. * * @param handler the handler to use or null for no handler. * @param policy the update policy to use or null for default policy. */ public Launcher(LaunchHandler handler, UpdatePolicy policy) { if (policy == null) policy = JNLPRuntime.getDefaultUpdatePolicy(); this.handler = handler; this.updatePolicy = policy; } /** * Sets the update policy used by launched applications. */ public void setUpdatePolicy(UpdatePolicy policy) { if (policy == null) throw new IllegalArgumentException(R("LNullUpdatePolicy")); this.updatePolicy = policy; } /** * Returns the update policy used when launching applications. */ public UpdatePolicy getUpdatePolicy() { return updatePolicy; } /** * Sets whether to launch the application in a new AppContext * (a separate event queue, look and feel, etc). If the * sun.awt.SunToolkit class is not present then this method * has no effect. The default value is true. */ public void setCreateAppContext(boolean context) { this.context = context; } /** * Returns whether applications are launched in their own * AppContext. */ public boolean isCreateAppContext() { return this.context; } /** * Launches a JNLP file by calling the launch method for the * appropriate file type. The application will be started in * a new window. * * @param file the JNLP file to launch * @return the application instance * @throws LaunchException if an error occurred while launching (also sent to handler) */ public ApplicationInstance launch(JNLPFile file) throws LaunchException { return launch(file, null); } /** * Launches a JNLP file inside the given container if it is an applet. Specifying a * container has no effect for Applcations and Installers. * * @param file the JNLP file to launch * @param cont the container in which to place the application, if it is an applet * @return the application instance * @throws LaunchException if an error occurred while launching (also sent to handler) */ public ApplicationInstance launch(JNLPFile file, Container cont) throws LaunchException { TgThread tg; //First checks whether offline-allowed tag is specified inside the jnlp //file. if (!file.getInformation().isOfflineAllowed()) { try { //Checks the offline/online status of the system. //If system is offline do not launch. InetAddress.getByName(file.getSourceLocation().getHost()); } catch (UnknownHostException ue) { System.err.println("File cannot be launched because offline-allowed tag not specified and system currently offline."); return null; } catch (Exception e) { System.err.println(e); } } if (file instanceof PluginBridge && cont != null) tg = new TgThread(file, cont, true); else if (cont == null) tg = new TgThread(file); else tg = new TgThread(file, cont); tg.start(); try { tg.join(); } catch (InterruptedException ex) { //By default, null is thrown here, and the message dialog is shown. throw launchWarning(new LaunchException(file, ex, R("LSMinor"), R("LCSystem"), R("LThreadInterrupted"), R("LThreadInterruptedInfo"))); } if (tg.getException() != null) throw tg.getException(); // passed to handler when first created if (handler != null) handler.launchCompleted(tg.getApplication()); return tg.getApplication(); } /** * Launches a JNLP file by calling the launch method for the * appropriate file type. * * @param location the URL of the JNLP file to launch * @throws LaunchException if there was an exception * @return the application instance */ public ApplicationInstance launch(URL location) throws LaunchException { return launch(toFile(location)); } /** * Launches a JNLP file by calling the launch method for the * appropriate file type in a different thread. * * @param file the JNLP file to launch */ public void launchBackground(JNLPFile file) { BgRunner runner = new BgRunner(file, null); new Thread(runner).start(); } /** * Launches the JNLP file at the specified location in the * background by calling the launch method for its file type. * * @param location the location of the JNLP file */ public void launchBackground(URL location) { BgRunner runner = new BgRunner(null, location); new Thread(runner).start(); } /** * Launches the JNLP file in a new JVM instance. The launched * application's output is sent to the system out and it's * standard input channel is closed. * * @param vmArgs the arguments to pass to the new JVM. Can be empty but * must not be null. * @param file the JNLP file to launch * @param javawsArgs the arguments to pass to the javaws command. Can be * an empty list but must not be null. * @throws LaunchException if there was an exception */ public void launchExternal(List vmArgs, JNLPFile file, List javawsArgs) throws LaunchException { List updatedArgs = new LinkedList(javawsArgs); if (file.getFileLocation() != null) updatedArgs.add(file.getFileLocation().toString()); else if (file.getSourceLocation() != null) updatedArgs.add(file.getFileLocation().toString()); else launchError(new LaunchException(file, null, R("LSFatal"), R("LCExternalLaunch"), R("LNullLocation"), R("LNullLocationInfo"))); launchExternal(vmArgs, updatedArgs); } /** * Launches the JNLP file in a new JVM instance. The launched * application's output is sent to the system out and it's * standard input channel is closed. * * @param url the URL of the JNLP file to launch * @throws LaunchException if there was an exception */ public void launchExternal(URL url) throws LaunchException { List javawsArgs = new LinkedList(); javawsArgs.add(url.toString()); launchExternal(new LinkedList(), javawsArgs); } /** * Launches the JNLP file at the specified location in a new JVM * instance. The launched application's output is sent to the * system out and it's standard input channel is closed. * @param vmArgs the arguments to pass to the jvm * @param javawsArgs the arguments to pass to javaws (aka Netx) * @throws LaunchException if there was an exception */ public void launchExternal(List vmArgs, List javawsArgs) throws LaunchException { try { List commands = new LinkedList(); // this property is set by the javaws launcher to point to the javaws binary String pathToWebstartBinary = System.getProperty("java.icedtea-web.bin"); commands.add(pathToWebstartBinary); // use -Jargument format to pass arguments to the JVM through the launcher for (String arg : vmArgs) { commands.add("-J" + arg); } commands.addAll(javawsArgs); String[] command = commands.toArray(new String[] {}); Process p = Runtime.getRuntime().exec(command); new StreamEater(p.getErrorStream()).start(); new StreamEater(p.getInputStream()).start(); p.getOutputStream().close(); } catch (NullPointerException ex) { throw launchError(new LaunchException(null, null, R("LSFatal"), R("LCExternalLaunch"), R("LNetxJarMissing"), R("LNetxJarMissingInfo"))); } catch (Exception ex) { throw launchError(new LaunchException(null, ex, R("LSFatal"), R("LCExternalLaunch"), R("LCouldNotLaunch"), R("LCouldNotLaunchInfo"))); } } /** * Returns the JNLPFile for the URL, with error handling. */ private JNLPFile toFile(URL location) throws LaunchException { try { JNLPFile file = null; try { file = new JNLPFile(location, (Version) null, true, updatePolicy); // strict } catch (ParseException ex) { file = new JNLPFile(location, (Version) null, false, updatePolicy); // only here if strict failed but lax did not fail LaunchException lex = launchWarning(new LaunchException(file, ex, R("LSMinor"), R("LCFileFormat"), R("LNotToSpec"), R("LNotToSpecInfo"))); if (lex != null) throw lex; } return file; } catch (Exception ex) { if (ex instanceof LaunchException) throw (LaunchException) ex; // already sent to handler when first thrown else // IO and Parse throw launchError(new LaunchException(null, ex, R("LSFatal"), R("LCReadError"), R("LCantRead"), R("LCantReadInfo"))); } } /** * Launches a JNLP application. This method should be called * from a thread in the application's thread group. */ protected ApplicationInstance launchApplication(JNLPFile file) throws LaunchException { if (!file.isApplication()) throw launchError(new LaunchException(file, null, R("LSFatal"), R("LCClient"), R("LNotApplication"), R("LNotApplicationInfo"))); markNetxRunning(); Runtime.getRuntime().addShutdownHook(new Thread() { public void run() { markNetxStopped(); } }); try { try { ServiceUtil.checkExistingSingleInstance(file); } catch (InstanceExistsException e) { return null; } if (JNLPRuntime.getForksAllowed() && file.needsNewVM()) { List netxArguments = new LinkedList(); netxArguments.add("-Xnofork"); netxArguments.addAll(JNLPRuntime.getInitialArguments()); launchExternal(file.getNewVMArgs(), netxArguments); return null; } final int preferredWidth = 500; final int preferredHeight = 400; JNLPSplashScreen splashScreen = null; URL splashImageURL = file.getInformation().getIconLocation( IconDesc.SPLASH, preferredWidth, preferredHeight); if (splashImageURL != null) { ResourceTracker resourceTracker = new ResourceTracker(true); resourceTracker.addResource(splashImageURL, file.getFileVersion(), updatePolicy); splashScreen = new JNLPSplashScreen(resourceTracker, null, null); splashScreen.setSplashImageURL(splashImageURL); if (splashScreen.isSplashScreenValid()) { splashScreen.setVisible(true); } } ApplicationInstance app = createApplication(file); app.initialize(); String mainName = file.getApplication().getMainClass(); // When the application-desc field is empty, we should take a // look at the main jar for the main class. if (mainName == null) { JARDesc mainJarDesc = file.getResources().getMainJAR(); File f = CacheUtil.getCacheFile(mainJarDesc.getLocation(), null); if (f != null) { JarFile mainJar = new JarFile(f); mainName = mainJar.getManifest(). getMainAttributes().getValue("Main-Class"); } } if (mainName == null) throw launchError(new LaunchException(file, null, R("LSFatal"), R("LCClient"), R("LCantDetermineMainClass"), R("LCantDetermineMainClassInfo"))); Class mainClass = app.getClassLoader().loadClass(mainName); Method main = mainClass.getMethod("main", new Class[] { String[].class }); String args[] = file.getApplication().getArguments(); SwingUtilities.invokeAndWait(new Runnable() { // dummy method to force Event Dispatch Thread creation public void run() { } }); setContextClassLoaderForAllThreads(app.getThreadGroup(), app.getClassLoader()); if (splashScreen != null) { if (splashScreen.isSplashScreenValid()) { splashScreen.setVisible(false); } splashScreen.dispose(); } main.setAccessible(true); main.invoke(null, new Object[] { args }); return app; } catch (LaunchException lex) { throw launchError(lex); } catch (Exception ex) { throw launchError(new LaunchException(file, ex, R("LSFatal"), R("LCLaunching"), R("LCouldNotLaunch"), R("LCouldNotLaunchInfo"))); } } /** * Set the classloader as the context classloader for all threads in * the given threadgroup. This is required to make some applications * work. For example, an application that provides a custom Swing LnF * may ask the swing thread to load resources from their JNLP, which * would only work if the Swing thread knows about the JNLPClassLoader. * * @param tg The threadgroup for which the context classloader should be set * @param classLoader the classloader to set as the context classloader */ private void setContextClassLoaderForAllThreads(ThreadGroup tg, ClassLoader classLoader) { /* be prepared for change in thread size */ int threadCountGuess = tg.activeCount(); Thread[] threads; do { threadCountGuess = threadCountGuess * 2; threads = new Thread[threadCountGuess]; tg.enumerate(threads, true); } while (threads[threadCountGuess - 1] != null); for (Thread thread : threads) { if (thread != null) { if (JNLPRuntime.isDebug()) { System.err.println("Setting " + classLoader + " as the classloader for thread " + thread.getName()); } thread.setContextClassLoader(classLoader); } } } /** * Launches a JNLP applet. This method should be called from a * thread in the application's thread group.

* * The enableCodeBase parameter adds the applet's codebase to * the locations searched for resources and classes. This can * slow down the applet loading but allows browser-style applets * that don't use JAR files exclusively to be run from a applet * JNLP file. If the applet JNLP file does not specify any * resources then the code base will be enabled regardless of * the specified value.

* * @param file the JNLP file * @param enableCodeBase whether to add the codebase URL to the classloader */ protected ApplicationInstance launchApplet(JNLPFile file, boolean enableCodeBase, Container cont) throws LaunchException { if (!file.isApplet()) throw launchError(new LaunchException(file, null, R("LSFatal"), R("LCClient"), R("LNotApplet"), R("LNotAppletInfo"))); try { AppletInstance applet = createApplet(file, enableCodeBase, cont); applet.initialize(); applet.getAppletEnvironment().startApplet(); // this should be a direct call to applet instance return applet; } catch (LaunchException lex) { throw launchError(lex); } catch (Exception ex) { throw launchError(new LaunchException(file, ex, R("LSFatal"), R("LCLaunching"), R("LCouldNotLaunch"), R("LCouldNotLaunchInfo"))); } } /** * Gets an ApplicationInstance, but does not launch the applet. */ protected ApplicationInstance getApplet(JNLPFile file, boolean enableCodeBase, Container cont) throws LaunchException { if (!file.isApplet()) throw launchError(new LaunchException(file, null, R("LSFatal"), R("LCClient"), R("LNotApplet"), R("LNotAppletInfo"))); try { AppletInstance applet = createApplet(file, enableCodeBase, cont); applet.initialize(); return applet; } catch (LaunchException lex) { throw launchError(lex); } catch (Exception ex) { throw launchError(new LaunchException(file, ex, R("LSFatal"), R("LCLaunching"), R("LCouldNotLaunch"), R("LCouldNotLaunchInfo"))); } } /** * Launches a JNLP installer. This method should be called from * a thread in the application's thread group. */ protected ApplicationInstance launchInstaller(JNLPFile file) throws LaunchException { throw launchError(new LaunchException(file, null, R("LSFatal"), R("LCNotSupported"), R("LNoInstallers"), R("LNoInstallersInfo"))); } /** * Create an AppletInstance. * * @param enableCodeBase whether to add the code base URL to the classloader */ protected AppletInstance createApplet(JNLPFile file, boolean enableCodeBase, Container cont) throws LaunchException { try { JNLPClassLoader loader = JNLPClassLoader.getInstance(file, updatePolicy); if (enableCodeBase || file.getResources().getJARs().length == 0) loader.enableCodeBase(); AppThreadGroup group = (AppThreadGroup) Thread.currentThread().getThreadGroup(); String appletName = file.getApplet().getMainClass(); //Classloader chokes if there's '/' in the path to the main class. //Must replace with '.' instead. appletName = appletName.replace('/', '.'); Class appletClass = loader.loadClass(appletName); Applet applet = (Applet) appletClass.newInstance(); AppletInstance appletInstance; if (cont == null) appletInstance = new AppletInstance(file, group, loader, applet); else appletInstance = new AppletInstance(file, group, loader, applet, cont); group.setApplication(appletInstance); loader.setApplication(appletInstance); setContextClassLoaderForAllThreads(appletInstance.getThreadGroup(), appletInstance.getClassLoader()); return appletInstance; } catch (Exception ex) { throw launchError(new LaunchException(file, ex, R("LSFatal"), R("LCInit"), R("LInitApplet"), R("LInitAppletInfo"))); } } /** * Creates an Applet object from a JNLPFile. This is mainly to be used with * gcjwebplugin. * @param file the PluginBridge to be used. * @param enableCodeBase whether to add the code base URL to the classloader. */ protected Applet createAppletObject(JNLPFile file, boolean enableCodeBase, Container cont) throws LaunchException { try { JNLPClassLoader loader = JNLPClassLoader.getInstance(file, updatePolicy); if (enableCodeBase || file.getResources().getJARs().length == 0) loader.enableCodeBase(); String appletName = file.getApplet().getMainClass(); //Classloader chokes if there's '/' in the path to the main class. //Must replace with '.' instead. appletName = appletName.replace('/', '.'); Class appletClass = loader.loadClass(appletName); Applet applet = (Applet) appletClass.newInstance(); return applet; } catch (Exception ex) { throw launchError(new LaunchException(file, ex, R("LSFatal"), R("LCInit"), R("LInitApplet"), R("LInitAppletInfo"))); } } /** * Creates an Application. */ protected ApplicationInstance createApplication(JNLPFile file) throws LaunchException { try { JNLPClassLoader loader = JNLPClassLoader.getInstance(file, updatePolicy); AppThreadGroup group = (AppThreadGroup) Thread.currentThread().getThreadGroup(); ApplicationInstance app = new ApplicationInstance(file, group, loader); group.setApplication(app); loader.setApplication(app); return app; } catch (Exception ex) { throw new LaunchException(file, ex, R("LSFatal"), R("LCInit"), R("LInitApplication"), R("LInitApplicationInfo")); } } /** * Create a thread group for the JNLP file. * * Note: if the JNLPFile is an applet (ie it is a subclass of PluginBridge) * then this method simply returns the existing ThreadGroup. The applet * ThreadGroup has to be created at an earlier point in the applet code. */ protected AppThreadGroup createThreadGroup(JNLPFile file) { AppThreadGroup appThreadGroup = null; if (file instanceof PluginBridge) { appThreadGroup = (AppThreadGroup) Thread.currentThread().getThreadGroup(); } else { appThreadGroup = new AppThreadGroup(mainGroup, file.getTitle()); } return appThreadGroup; } /** * Send n launch error to the handler, if set, and also to the * caller. */ private LaunchException launchError(LaunchException ex) { if (handler != null) handler.launchError(ex); return ex; } /** * Send a launch error to the handler, if set, and to the * caller only if the handler indicated that the launch should * continue despite the warning. * * @return an exception to throw if the launch should be aborted, or null otherwise */ private LaunchException launchWarning(LaunchException ex) { if (handler != null) if (!handler.launchWarning(ex)) // no need to destroy the app b/c it hasn't started return ex; // chose to abort return null; // chose to continue, or no handler } /** * Indicate that netx is running by creating the {@link JNLPRuntime#INSTANCE_FILE} and * acquiring a shared lock on it */ private void markNetxRunning() { try { String message = "This file is used to check if netx is running"; File netxRunningFile = new File(JNLPRuntime.getConfiguration() .getProperty(DeploymentConfiguration.KEY_USER_NETX_RUNNING_FILE)); if (!netxRunningFile.exists()) { netxRunningFile.getParentFile().mkdirs(); FileUtils.createRestrictedFile(netxRunningFile, true); FileOutputStream fos = new FileOutputStream(netxRunningFile); try { fos.write(message.getBytes()); } finally { fos.close(); } } FileInputStream is = new FileInputStream(netxRunningFile); FileChannel channel = is.getChannel(); fileLock = channel.tryLock(0, Long.MAX_VALUE, true); if (fileLock != null && fileLock.isShared()) { if (JNLPRuntime.isDebug()) { System.out.println("Acquired shared lock on " + netxRunningFile.toString() + " to indicate javaws is running"); } } else { fileLock = null; } } catch (IOException e) { e.printStackTrace(); } } /** * Indicate that netx is stopped by releasing the shared lock on * {@link JNLPRuntime#INSTANCE_FILE}. */ private void markNetxStopped() { if (fileLock == null) { return; } try { fileLock.release(); fileLock.channel().close(); fileLock = null; if (JNLPRuntime.isDebug()) { String file = JNLPRuntime.getConfiguration() .getProperty(DeploymentConfiguration.KEY_USER_NETX_RUNNING_FILE); System.out.println("Release shared lock on " + file); } } catch (IOException e) { e.printStackTrace(); } } /** * Do hacks on per-application level to allow different AppContexts to work * * @see JNLPRuntime#doMainAppContextHacks */ private static void doPerApplicationAppContextHacks() { /* * With OpenJDK6 (but not with 7) a per-AppContext dtd is maintained. * This dtd is created by the ParserDelgate. However, the code in * HTMLEditorKit (used to render HTML in labels and textpanes) creates * the ParserDelegate only if there are no existing ParserDelegates. The * result is that all other AppContexts see a null dtd. */ new ParserDelegator(); } /** * This runnable is used to call the appropriate launch method * for the application, applet, or installer in its thread group. */ private class TgThread extends Thread { // ThreadGroupThread private JNLPFile file; private ApplicationInstance application; private LaunchException exception; private Container cont; private boolean isPlugin = false; TgThread(JNLPFile file) { this(file, null); } TgThread(JNLPFile file, Container cont) { super(createThreadGroup(file), file.getTitle()); this.file = file; this.cont = cont; } TgThread(JNLPFile file, Container cont, boolean isPlugin) { super(createThreadGroup(file), file.getTitle()); this.file = file; this.cont = cont; this.isPlugin = isPlugin; } public void run() { try { // Do not create new AppContext if we're using NetX and icedteaplugin. // The plugin needs an AppContext too, but it has to be created earlier. if (context && !isPlugin) SunToolkit.createNewAppContext(); doPerApplicationAppContextHacks(); if (isPlugin) { // Do not display download indicators if we're using gcjwebplugin. JNLPRuntime.setDefaultDownloadIndicator(null); application = getApplet(file, true, cont); } else { if (file.isApplication()) application = launchApplication(file); else if (file.isApplet()) application = launchApplet(file, true, cont); // enable applet code base else if (file.isInstaller()) application = launchInstaller(file); else throw launchError(new LaunchException(file, null, R("LSFatal"), R("LCClient"), R("LNotLaunchable"), R("LNotLaunchableInfo"))); } } catch (LaunchException ex) { ex.printStackTrace(); exception = ex; // Exit if we can't launch the application. if (exitOnFailure) System.exit(0); } } public LaunchException getException() { return exception; } public ApplicationInstance getApplication() { return application; } }; /** * This runnable is used by the launchBackground * methods to launch a JNLP file from a separate thread. */ private class BgRunner implements Runnable { private JNLPFile file; private URL location; BgRunner(JNLPFile file, URL location) { this.file = file; this.location = location; } public void run() { try { if (file != null) launch(file); if (location != null) launch(location); } catch (LaunchException ex) { // launch method communicates error conditions to the // handler if it exists, otherwise we don't care because // there's nothing that can be done about the exception. } } }; }