src/jalview/util/BrowserLauncher.java

   1 /********************
   2  * 2004 Jalview Reengineered
   3  * Barton Group
   4  * Dundee University
   5  *
   6  * AM Waterhouse
   7  *******************/
   8
   9 package jalview.util;
  10
  11 import java.io.File;
  12 import java.io.IOException;
  13 import java.lang.reflect.Constructor;
  14 import java.lang.reflect.Field;
  15 import java.lang.reflect.InvocationTargetException;
  16 import java.lang.reflect.Method;
  17
  18 /**
  19  * BrowserLauncher is a class that provides one static method, openURL, which opens the default
  20  * web browser for the current user of the system to the given URL.  It may support other
  21  * protocols depending on the system -- mailto, ftp, etc. -- but that has not been rigorously
  22  * tested and is not guaranteed to work.
  23  * <p>
  24  * Yes, this is platform-specific code, and yes, it may rely on classes on certain platforms
  25  * that are not part of the standard JDK.  What we're trying to do, though, is to take something
  26  * that's frequently desirable but inherently platform-specific -- opening a default browser --
  27  * and allow programmers (you, for example) to do so without worrying about dropping into native
  28  * code or doing anything else similarly evil.
  29  * <p>
  30  * Anyway, this code is completely in Java and will run on all JDK 1.1-compliant systems without
  31  * modification or a need for additional libraries.  All classes that are required on certain
  32  * platforms to allow this to run are dynamically loaded at runtime via reflection and, if not
  33  * found, will not cause this to do anything other than returning an error when opening the
  34  * browser.
  35  * <p>
  36  * There are certain system requirements for this class, as it's running through Runtime.exec(),
  37  * which is Java's way of making a native system call.  Currently, this requires that a Macintosh
  38  * have a Finder which supports the GURL event, which is true for Mac OS 8.0 and 8.1 systems that
  39  * have the Internet Scripting AppleScript dictionary installed in the Scripting Additions folder
  40  * in the Extensions folder (which is installed by default as far as I know under Mac OS 8.0 and
  41  * 8.1), and for all Mac OS 8.5 and later systems.  On Windows, it only runs under Win32 systems
  42  * (Windows 95, 98, and NT 4.0, as well as later versions of all).  On other systems, this drops
  43  * back from the inherently platform-sensitive concept of a default browser and simply attempts
  44  * to launch Netscape via a shell command.
  45  * <p>
  46  * This code is Copyright 1999-2001 by Eric Albert (ejalbert\@cs.stanford.edu) and may be
  47  * redistributed or modified in any form without restrictions as long as the portion of this
  48  * comment from this paragraph through the end of the comment is not removed.  The author
  49  * requests that he be notified of any application, applet, or other binary that makes use of
  50  * this code, but that's more out of curiosity than anything and is not required.  This software
  51  * includes no warranty.  The author is not repsonsible for any loss of data or functionality
  52  * or any adverse or unexpected effects of using this software.
  53  * <p>
  54  * Credits:
  55  * <br>Steven Spencer, JavaWorld magazine (<a href="http://www.javaworld.com/javaworld/javatips/jw-javatip66.html">Java Tip 66</a>)
  56  * <br>Thanks also to Ron B. Yeh, Eric Shapiro, Ben Engber, Paul Teitlebaum, Andrea Cantatore,
  57  * Larry Barowski, Trevor Bedzek, Frank Miedrich, and Ron Rabakukk
  58  *
  59  * @author Eric Albert (<a href="mailto:ejalbert@cs.stanford.edu">ejalbert@cs.stanford.edu</a>)
  60  * @version 1.4b1 (Released June 20, 2001)
  61  */
  62 public class BrowserLauncher {
  63
  64         /**
  65          * The Java virtual machine that we are running on.  Actually, in most cases we only care
  66          * about the operating system, but some operating systems require us to switch on the VM. */
  67         private static int jvm;
  68
  69         /** The browser for the system */
  70         private static Object browser;
  71
  72         /**
  73          * Caches whether any classes, methods, and fields that are not part of the JDK and need to
  74          * be dynamically loaded at runtime loaded successfully.
  75          * <p>
  76          * Note that if this is <code>false</code>, <code>openURL()</code> will always return an
  77          * IOException.
  78          */
  79         private static boolean loadedWithoutErrors;
  80
  81         /** The com.apple.mrj.MRJFileUtils class */
  82         private static Class mrjFileUtilsClass;
  83
  84         /** The com.apple.mrj.MRJOSType class */
  85         private static Class mrjOSTypeClass;
  86
  87         /** The com.apple.MacOS.AEDesc class */
  88         private static Class aeDescClass;
  89
  90         /** The &lt;init&gt;(int) method of com.apple.MacOS.AETarget */
  91         private static Constructor aeTargetConstructor;
  92
  93         /** The &lt;init&gt;(int, int, int) method of com.apple.MacOS.AppleEvent */
  94         private static Constructor appleEventConstructor;
  95
  96         /** The &lt;init&gt;(String) method of com.apple.MacOS.AEDesc */
  97         private static Constructor aeDescConstructor;
  98
  99         /** The findFolder method of com.apple.mrj.MRJFileUtils */
 100         private static Method findFolder;
 101
 102         /** The getFileCreator method of com.apple.mrj.MRJFileUtils */
 103         private static Method getFileCreator;
 104
 105         /** The getFileType method of com.apple.mrj.MRJFileUtils */
 106         private static Method getFileType;
 107
 108         /** The openURL method of com.apple.mrj.MRJFileUtils */
 109         private static Method openURL;
 110
 111         /** The makeOSType method of com.apple.MacOS.OSUtils */
 112         private static Method makeOSType;
 113
 114         /** The putParameter method of com.apple.MacOS.AppleEvent */
 115         private static Method putParameter;
 116
 117         /** The sendNoReply method of com.apple.MacOS.AppleEvent */
 118         private static Method sendNoReply;
 119
 120         /** Actually an MRJOSType pointing to the System Folder on a Macintosh */
 121         private static Object kSystemFolderType;
 122
 123         /** The keyDirectObject AppleEvent parameter type */
 124         private static Integer keyDirectObject;
 125
 126         /** The kAutoGenerateReturnID AppleEvent code */
 127         private static Integer kAutoGenerateReturnID;
 128
 129         /** The kAnyTransactionID AppleEvent code */
 130         private static Integer kAnyTransactionID;
 131
 132         /** The linkage object required for JDirect 3 on Mac OS X. */
 133         private static Object linkage;
 134
 135         /** The framework to reference on Mac OS X */
 136         private static final String JDirect_MacOSX = "/System/Library/Frameworks/Carbon.framework/Frameworks/HIToolbox.framework/HIToolbox";
 137
 138         /** JVM constant for MRJ 2.0 */
 139         private static final int MRJ_2_0 = 0;
 140
 141         /** JVM constant for MRJ 2.1 or later */
 142         private static final int MRJ_2_1 = 1;
 143
 144         /** JVM constant for Java on Mac OS X 10.0 (MRJ 3.0) */
 145         private static final int MRJ_3_0 = 3;
 146
 147         /** JVM constant for MRJ 3.1 */
 148         private static final int MRJ_3_1 = 4;
 149
 150         /** JVM constant for any Windows NT JVM */
 151         private static final int WINDOWS_NT = 5;
 152
 153         /** JVM constant for any Windows 9x JVM */
 154         private static final int WINDOWS_9x = 6;
 155
 156         /** JVM constant for any other platform */
 157         private static final int OTHER = -1;
 158
 159         /**
 160          * The file type of the Finder on a Macintosh.  Hardcoding "Finder" would keep non-U.S. English
 161          * systems from working properly.
 162          */
 163         private static final String FINDER_TYPE = "FNDR";
 164
 165         /**
 166          * The creator code of the Finder on a Macintosh, which is needed to send AppleEvents to the
 167          * application.
 168          */
 169         private static final String FINDER_CREATOR = "MACS";
 170
 171         /** The name for the AppleEvent type corresponding to a GetURL event. */
 172         private static final String GURL_EVENT = "GURL";
 173
 174         /**
 175          * The first parameter that needs to be passed into Runtime.exec() to open the default web
 176          * browser on Windows.
 177          */
 178     private static final String FIRST_WINDOWS_PARAMETER = "/c";
 179
 180     /** The second parameter for Runtime.exec() on Windows. */
 181     private static final String SECOND_WINDOWS_PARAMETER = "start";
 182
 183     /**
 184      * The third parameter for Runtime.exec() on Windows.  This is a "title"
 185      * parameter that the command line expects.  Setting this parameter allows
 186      * URLs containing spaces to work.
 187      */
 188     private static final String THIRD_WINDOWS_PARAMETER = "\"\"";
 189
 190         /**
 191          * The shell parameters for Netscape that opens a given URL in an already-open copy of Netscape
 192          * on many command-line systems.
 193          */
 194         private static final String NETSCAPE_REMOTE_PARAMETER = "-remote";
 195         private static final String NETSCAPE_OPEN_PARAMETER_START = "openURL(";
 196         private static final String NETSCAPE_OPEN_NEW_WINDOW = ", new-window";
 197         private static final String NETSCAPE_OPEN_PARAMETER_END = ")";
 198
 199         /**
 200          * The message from any exception thrown throughout the initialization process.
 201          */
 202         private static String errorMessage;
 203
 204         /**
 205          * An initialization block that determines the operating system and loads the necessary
 206          * runtime data.
 207          */
 208         static {
 209                 loadedWithoutErrors = true;
 210                 String osName = System.getProperty("os.name");
 211                 if (osName.startsWith("Mac OS")) {
 212                         String mrjVersion = System.getProperty("mrj.version");
 213                         String majorMRJVersion = mrjVersion.substring(0, 3);
 214                         try {
 215                                 double version = Double.valueOf(majorMRJVersion).doubleValue();
 216                                 if (version == 2) {
 217                                         jvm = MRJ_2_0;
 218                                 } else if (version >= 2.1 && version < 3) {
 219                                         // Assume that all 2.x versions of MRJ work the same.  MRJ 2.1 actually
 220                                         // works via Runtime.exec() and 2.2 supports that but has an openURL() method
 221                                         // as well that we currently ignore.
 222                                         jvm = MRJ_2_1;
 223                                 } else if (version == 3.0) {
 224                                         jvm = MRJ_3_0;
 225                                 } else if (version >= 3.1) {
 226                                         // Assume that all 3.1 and later versions of MRJ work the same.
 227                                         jvm = MRJ_3_1;
 228                                 } else {
 229                                         loadedWithoutErrors = false;
 230                                         errorMessage = "Unsupported MRJ version: " + version;
 231                                 }
 232                         } catch (NumberFormatException nfe) {
 233                                 loadedWithoutErrors = false;
 234                                 errorMessage = "Invalid MRJ version: " + mrjVersion;
 235                         }
 236                 } else if (osName.startsWith("Windows")) {
 237                         if (osName.indexOf("9") != -1) {
 238                                 jvm = WINDOWS_9x;
 239                         } else {
 240                                 jvm = WINDOWS_NT;
 241                         }
 242                 } else {
 243                         jvm = OTHER;
 244                 }
 245
 246                 if (loadedWithoutErrors) {      // if we haven't hit any errors yet
 247                         loadedWithoutErrors = loadClasses();
 248                 }
 249         }
 250
 251         /**
 252          * This class should be never be instantiated; this just ensures so.
 253          */
 254         private BrowserLauncher() { }
 255
 256         /**
 257          * Called by a static initializer to load any classes, fields, and methods required at runtime
 258          * to locate the user's web browser.
 259          * @return <code>true</code> if all intialization succeeded
 260          *                      <code>false</code> if any portion of the initialization failed
 261          */
 262         private static boolean loadClasses() {
 263                 switch (jvm) {
 264                         case MRJ_2_0:
 265                                 try {
 266                                         Class aeTargetClass = Class.forName("com.apple.MacOS.AETarget");
 267                                         Class osUtilsClass = Class.forName("com.apple.MacOS.OSUtils");
 268                                         Class appleEventClass = Class.forName("com.apple.MacOS.AppleEvent");
 269                                         Class aeClass = Class.forName("com.apple.MacOS.ae");
 270                                         aeDescClass = Class.forName("com.apple.MacOS.AEDesc");
 271
 272                                         aeTargetConstructor = aeTargetClass.getDeclaredConstructor(new Class [] { int.class });
 273                                         appleEventConstructor = appleEventClass.getDeclaredConstructor(new Class[] { int.class, int.class, aeTargetClass, int.class, int.class });
 274                                         aeDescConstructor = aeDescClass.getDeclaredConstructor(new Class[] { String.class });
 275
 276                                         makeOSType = osUtilsClass.getDeclaredMethod("makeOSType", new Class [] { String.class });
 277                                         putParameter = appleEventClass.getDeclaredMethod("putParameter", new Class[] { int.class, aeDescClass });
 278                                         sendNoReply = appleEventClass.getDeclaredMethod("sendNoReply", new Class[] { });
 279
 280                                         Field keyDirectObjectField = aeClass.getDeclaredField("keyDirectObject");
 281                                         keyDirectObject = (Integer) keyDirectObjectField.get(null);
 282                                         Field autoGenerateReturnIDField = appleEventClass.getDeclaredField("kAutoGenerateReturnID");
 283                                         kAutoGenerateReturnID = (Integer) autoGenerateReturnIDField.get(null);
 284                                         Field anyTransactionIDField = appleEventClass.getDeclaredField("kAnyTransactionID");
 285                                         kAnyTransactionID = (Integer) anyTransactionIDField.get(null);
 286                                 } catch (ClassNotFoundException cnfe) {
 287                                         errorMessage = cnfe.getMessage();
 288                                         return false;
 289                                 } catch (NoSuchMethodException nsme) {
 290                                         errorMessage = nsme.getMessage();
 291                                         return false;
 292                                 } catch (NoSuchFieldException nsfe) {
 293                                         errorMessage = nsfe.getMessage();
 294                                         return false;
 295                                 } catch (IllegalAccessException iae) {
 296                                         errorMessage = iae.getMessage();
 297                                         return false;
 298                                 }
 299                                 break;
 300                         case MRJ_2_1:
 301                                 try {
 302                                         mrjFileUtilsClass = Class.forName("com.apple.mrj.MRJFileUtils");
 303                                         mrjOSTypeClass = Class.forName("com.apple.mrj.MRJOSType");
 304                                         Field systemFolderField = mrjFileUtilsClass.getDeclaredField("kSystemFolderType");
 305                                         kSystemFolderType = systemFolderField.get(null);
 306                                         findFolder = mrjFileUtilsClass.getDeclaredMethod("findFolder", new Class[] { mrjOSTypeClass });
 307                                         getFileCreator = mrjFileUtilsClass.getDeclaredMethod("getFileCreator", new Class[] { File.class });
 308                                         getFileType = mrjFileUtilsClass.getDeclaredMethod("getFileType", new Class[] { File.class });
 309                                 } catch (ClassNotFoundException cnfe) {
 310                                         errorMessage = cnfe.getMessage();
 311                                         return false;
 312                                 } catch (NoSuchFieldException nsfe) {
 313                                         errorMessage = nsfe.getMessage();
 314                                         return false;
 315                                 } catch (NoSuchMethodException nsme) {
 316                                         errorMessage = nsme.getMessage();
 317                                         return false;
 318                                 } catch (SecurityException se) {
 319                                         errorMessage = se.getMessage();
 320                                         return false;
 321                                 } catch (IllegalAccessException iae) {
 322                                         errorMessage = iae.getMessage();
 323                                         return false;
 324                                 }
 325                                 break;
 326                         case MRJ_3_0:
 327                             try {
 328                                         Class linker = Class.forName("com.apple.mrj.jdirect.Linker");
 329                                         Constructor constructor = linker.getConstructor(new Class[]{ Class.class });
 330                                         linkage = constructor.newInstance(new Object[] { BrowserLauncher.class });
 331                                 } catch (ClassNotFoundException cnfe) {
 332                                         errorMessage = cnfe.getMessage();
 333                                         return false;
 334                                 } catch (NoSuchMethodException nsme) {
 335                                         errorMessage = nsme.getMessage();
 336                                         return false;
 337                                 } catch (InvocationTargetException ite) {
 338                                         errorMessage = ite.getMessage();
 339                                         return false;
 340                                 } catch (InstantiationException ie) {
 341                                         errorMessage = ie.getMessage();
 342                                         return false;
 343                                 } catch (IllegalAccessException iae) {
 344                                         errorMessage = iae.getMessage();
 345                                         return false;
 346                                 }
 347                                 break;
 348                         case MRJ_3_1:
 349                                 try {
 350                                         mrjFileUtilsClass = Class.forName("com.apple.mrj.MRJFileUtils");
 351                                         openURL = mrjFileUtilsClass.getDeclaredMethod("openURL", new Class[] { String.class });
 352                                 } catch (ClassNotFoundException cnfe) {
 353                                         errorMessage = cnfe.getMessage();
 354                                         return false;
 355                                 } catch (NoSuchMethodException nsme) {
 356                                         errorMessage = nsme.getMessage();
 357                                         return false;
 358                                 }
 359                                 break;
 360                         default:
 361                             break;
 362                 }
 363                 return true;
 364         }
 365
 366         /**
 367          * Attempts to locate the default web browser on the local system.  Caches results so it
 368          * only locates the browser once for each use of this class per JVM instance.
 369          * @return The browser for the system.  Note that this may not be what you would consider
 370          *                      to be a standard web browser; instead, it's the application that gets called to
 371          *                      open the default web browser.  In some cases, this will be a non-String object
 372          *                      that provides the means of calling the default browser.
 373          */
 374         private static Object locateBrowser() {
 375                 if (browser != null) {
 376                         return browser;
 377                 }
 378                 switch (jvm) {
 379                         case MRJ_2_0:
 380                                 try {
 381                                         Integer finderCreatorCode = (Integer) makeOSType.invoke(null, new Object[] { FINDER_CREATOR });
 382                                         Object aeTarget = aeTargetConstructor.newInstance(new Object[] { finderCreatorCode });
 383                                         Integer gurlType = (Integer) makeOSType.invoke(null, new Object[] { GURL_EVENT });
 384                                         Object appleEvent = appleEventConstructor.newInstance(new Object[] { gurlType, gurlType, aeTarget, kAutoGenerateReturnID, kAnyTransactionID });
 385                                         // Don't set browser = appleEvent because then the next time we call
 386                                         // locateBrowser(), we'll get the same AppleEvent, to which we'll already have
 387                                         // added the relevant parameter. Instead, regenerate the AppleEvent every time.
 388                                         // There's probably a way to do this better; if any has any ideas, please let
 389                                         // me know.
 390                                         return appleEvent;
 391                                 } catch (IllegalAccessException iae) {
 392                                         browser = null;
 393                                         errorMessage = iae.getMessage();
 394                                         return browser;
 395                                 } catch (InstantiationException ie) {
 396                                         browser = null;
 397                                         errorMessage = ie.getMessage();
 398                                         return browser;
 399                                 } catch (InvocationTargetException ite) {
 400                                         browser = null;
 401                                         errorMessage = ite.getMessage();
 402                                         return browser;
 403                                 }
 404                         case MRJ_2_1:
 405                                 File systemFolder;
 406                                 try {
 407                                         systemFolder = (File) findFolder.invoke(null, new Object[] { kSystemFolderType });
 408                                 } catch (IllegalArgumentException iare) {
 409                                         browser = null;
 410                                         errorMessage = iare.getMessage();
 411                                         return browser;
 412                                 } catch (IllegalAccessException iae) {
 413                                         browser = null;
 414                                         errorMessage = iae.getMessage();
 415                                         return browser;
 416                                 } catch (InvocationTargetException ite) {
 417                                         browser = null;
 418                                         errorMessage = ite.getTargetException().getClass() + ": " + ite.getTargetException().getMessage();
 419                                         return browser;
 420                                 }
 421                                 String[] systemFolderFiles = systemFolder.list();
 422                                 // Avoid a FilenameFilter because that can't be stopped mid-list
 423                                 for(int i = 0; i < systemFolderFiles.length; i++) {
 424                                         try {
 425                                                 File file = new File(systemFolder, systemFolderFiles[i]);
 426                                                 if (!file.isFile()) {
 427                                                         continue;
 428                                                 }
 429                                                 // We're looking for a file with a creator code of 'MACS' and
 430                                                 // a type of 'FNDR'.  Only requiring the type results in non-Finder
 431                                                 // applications being picked up on certain Mac OS 9 systems,
 432                                                 // especially German ones, and sending a GURL event to those
 433                                                 // applications results in a logout under Multiple Users.
 434                                                 Object fileType = getFileType.invoke(null, new Object[] { file });
 435                                                 if (FINDER_TYPE.equals(fileType.toString())) {
 436                                                         Object fileCreator = getFileCreator.invoke(null, new Object[] { file });
 437                                                         if (FINDER_CREATOR.equals(fileCreator.toString())) {
 438                                                                 browser = file.toString();      // Actually the Finder, but that's OK
 439                                                                 return browser;
 440                                                         }
 441                                                 }
 442                                         } catch (IllegalArgumentException iare) {
 443                                                 browser = browser;
 444                                                 errorMessage = iare.getMessage();
 445                                                 return null;
 446                                         } catch (IllegalAccessException iae) {
 447                                                 browser = null;
 448                                                 errorMessage = iae.getMessage();
 449                                                 return browser;
 450                                         } catch (InvocationTargetException ite) {
 451                                                 browser = null;
 452                                                 errorMessage = ite.getTargetException().getClass() + ": " + ite.getTargetException().getMessage();
 453                                                 return browser;
 454                                         }
 455                                 }
 456                                 browser = null;
 457                                 break;
 458                         case MRJ_3_0:
 459                         case MRJ_3_1:
 460                                 browser = "";   // Return something non-null
 461                                 break;
 462                         case WINDOWS_NT:
 463                                 browser = "cmd.exe";
 464                                 break;
 465                         case WINDOWS_9x:
 466                                 browser = "command.com";
 467                                 break;
 468                         case OTHER:
 469                         default:
 470                                 browser = jalview.bin.Cache.applicationProperties.getProperty("jalview.browser");
 471                                 if (browser==null) {
 472                                   // hope firefox exists :-/
 473                                   browser = "firefox";
 474                                 }
 475                                 break;
 476                 }
 477                 return browser;
 478         }
 479
 480         /**
 481          * Attempts to open the default web browser to the given URL.
 482          * @param url The URL to open
 483          * @throws IOException If the web browser could not be located or does not run
 484          */
 485         public static void openURL(String url) throws IOException {
 486                 if (!loadedWithoutErrors) {
 487                         throw new IOException("Exception in finding browser: " + errorMessage);
 488                 }
 489                 Object browser = locateBrowser();
 490                 if (browser == null) {
 491                         throw new IOException("Unable to locate browser: " + errorMessage);
 492                 }
 493
 494                 switch (jvm) {
 495                         case MRJ_2_0:
 496                                 Object aeDesc = null;
 497                                 try {
 498                                         aeDesc = aeDescConstructor.newInstance(new Object[] { url });
 499                                         putParameter.invoke(browser, new Object[] { keyDirectObject, aeDesc });
 500                                         sendNoReply.invoke(browser, new Object[] { });
 501                                 } catch (InvocationTargetException ite) {
 502                                         throw new IOException("InvocationTargetException while creating AEDesc: " + ite.getMessage());
 503                                 } catch (IllegalAccessException iae) {
 504                                         throw new IOException("IllegalAccessException while building AppleEvent: " + iae.getMessage());
 505                                 } catch (InstantiationException ie) {
 506                                         throw new IOException("InstantiationException while creating AEDesc: " + ie.getMessage());
 507                                 } finally {
 508                                         aeDesc = null;  // Encourage it to get disposed if it was created
 509                                         browser = null; // Ditto
 510                                 }
 511                                 break;
 512                         case MRJ_2_1:
 513                                 Runtime.getRuntime().exec(new String[] { (String) browser, url } );
 514                                 break;
 515                         case MRJ_3_0:
 516                                 int[] instance = new int[1];
 517                                 int result = ICStart(instance, 0);
 518                                 if (result == 0) {
 519                                         int[] selectionStart = new int[] { 0 };
 520                                         byte[] urlBytes = url.getBytes();
 521                                         int[] selectionEnd = new int[] { urlBytes.length };
 522                                         result = ICLaunchURL(instance[0], new byte[] { 0 }, urlBytes,
 523                                                                                         urlBytes.length, selectionStart,
 524                                                                                         selectionEnd);
 525                                         if (result == 0) {
 526                                                 // Ignore the return value; the URL was launched successfully
 527                                                 // regardless of what happens here.
 528                                                 ICStop(instance);
 529                                         } else {
 530                                                 throw new IOException("Unable to launch URL: " + result);
 531                                         }
 532                                 } else {
 533                                         throw new IOException("Unable to create an Internet Config instance: " + result);
 534                                 }
 535                                 break;
 536                         case MRJ_3_1:
 537                                 try {
 538                                         openURL.invoke(null, new Object[] { url });
 539                                 } catch (InvocationTargetException ite) {
 540                                         throw new IOException("InvocationTargetException while calling openURL: " + ite.getMessage());
 541                                 } catch (IllegalAccessException iae) {
 542                                         throw new IOException("IllegalAccessException while calling openURL: " + iae.getMessage());
 543                                 }
 544                                 break;
 545                     case WINDOWS_NT:
 546                     case WINDOWS_9x:
 547                             // Add quotes around the URL to allow ampersands and other special
 548                             // characters to work.
 549                                 Process process = Runtime.getRuntime().exec(new String[] { (String) browser,
 550                                                                                                                                 FIRST_WINDOWS_PARAMETER,
 551                                                                                                                                 SECOND_WINDOWS_PARAMETER,
 552                                                                                                                                 THIRD_WINDOWS_PARAMETER,
 553                                                                                                                                 '"' + url + '"' });
 554                                 // This avoids a memory leak on some versions of Java on Windows.
 555                                 // That's hinted at in <http://developer.java.sun.com/developer/qow/archive/68/>.
 556                                 try {
 557                                         process.waitFor();
 558                                         process.exitValue();
 559                                 } catch (InterruptedException ie) {
 560                                         throw new IOException("InterruptedException while launching browser: " + ie.getMessage());
 561                                 }
 562                                 break;
 563                         case OTHER:
 564                                 // Assume that we're on Unix and that Netscape (actually Firefox) is installed
 565
 566                                 // First, attempt to open the URL in a currently running session of Netscape
 567                                 process = Runtime.getRuntime().exec(new String[] { (String) browser,
 568                                                                                                         NETSCAPE_REMOTE_PARAMETER,
 569                                                                                                         NETSCAPE_OPEN_PARAMETER_START +
 570                                                                                                         url +
 571                                                                                                         NETSCAPE_OPEN_NEW_WINDOW +
 572                                                                                                         NETSCAPE_OPEN_PARAMETER_END });
 573                                 try {
 574                                         int exitCode = process.waitFor();
 575                                         if (exitCode != 0) {    // if Netscape was not open
 576                                                 Runtime.getRuntime().exec(new String[] { (String) browser, url });
 577                                         }
 578                                 } catch (InterruptedException ie) {
 579                                         throw new IOException("InterruptedException while launching browser: " + ie.getMessage());
 580                                 }
 581                                 break;
 582                         default:
 583                                 // This should never occur, but if it does, we'll try the simplest thing possible
 584                                 Runtime.getRuntime().exec(new String[] { (String) browser, url });
 585                                 break;
 586                 }
 587         }
 588
 589         /**
 590          * Methods required for Mac OS X.  The presence of native methods does not cause
 591          * any problems on other platforms.
 592          */
 593         private native static int ICStart(int[] instance, int signature);
 594         private native static int ICStop(int[] instance);
 595         private native static int ICLaunchURL(int instance, byte[] hint, byte[] data, int len,
 596                                                                                         int[] selectionStart, int[] selectionEnd);
 597 }