src/edu/stanford/ejalbert/BrowserLauncher.java

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