* Yes, this is platform-specific code, and yes, it may rely on classes on certain platforms * that are not part of the standard JDK. What we're trying to do, though, is to take something * that's frequently desirable but inherently platform-specific -- opening a default browser -- * and allow programmers (you, for example) to do so without worrying about dropping into native * code or doing anything else similarly evil. *
* Anyway, this code is completely in Java and will run on all JDK 1.1-compliant systems without * modification or a need for additional libraries. All classes that are required on certain * platforms to allow this to run are dynamically loaded at runtime via reflection and, if not * found, will not cause this to do anything other than returning an error when opening the * browser. *
* There are certain system requirements for this class, as it's running through Runtime.exec(), * which is Java's way of making a native system call. Currently, this requires that a Macintosh * have a Finder which supports the GURL event, which is true for Mac OS 8.0 and 8.1 systems that * have the Internet Scripting AppleScript dictionary installed in the Scripting Additions folder * in the Extensions folder (which is installed by default as far as I know under Mac OS 8.0 and * 8.1), and for all Mac OS 8.5 and later systems. On Windows, it only runs under Win32 systems * (Windows 95, 98, and NT 4.0, as well as later versions of all). On other systems, this drops * back from the inherently platform-sensitive concept of a default browser and simply attempts * to launch Netscape via a shell command. *
* This code is Copyright 1999-2001 by Eric Albert (ejalbert\@cs.stanford.edu) and may be * redistributed or modified in any form without restrictions as long as the portion of this * comment from this paragraph through the end of the comment is not removed. The author * requests that he be notified of any application, applet, or other binary that makes use of * this code, but that's more out of curiosity than anything and is not required. This software * includes no warranty. The author is not repsonsible for any loss of data or functionality * or any adverse or unexpected effects of using this software. *
* Credits:
*
Steven Spencer, JavaWorld magazine (Java Tip 66)
*
Thanks also to Ron B. Yeh, Eric Shapiro, Ben Engber, Paul Teitlebaum, Andrea Cantatore,
* Larry Barowski, Trevor Bedzek, Frank Miedrich, and Ron Rabakukk
*
* @author Eric Albert (ejalbert@cs.stanford.edu)
* @version 1.4b1 (Released June 20, 2001)
*/
public class BrowserLauncher
{
/**
* The Java virtual machine that we are running on. Actually, in most cases we only care
* about the operating system, but some operating systems require us to switch on the VM. */
private static int jvm;
/** The browser for the system */
private static Object browser;
/**
* Caches whether any classes, methods, and fields that are not part of the JDK and need to
* be dynamically loaded at runtime loaded successfully.
*
* Note that if this is false, openURL() will always return an
* IOException.
*/
private static boolean loadedWithoutErrors;
/** The com.apple.mrj.MRJFileUtils class */
private static Class mrjFileUtilsClass;
/** The com.apple.mrj.MRJOSType class */
private static Class mrjOSTypeClass;
/** The com.apple.MacOS.AEDesc class */
private static Class aeDescClass;
/** The <init>(int) method of com.apple.MacOS.AETarget */
private static Constructor aeTargetConstructor;
/** The <init>(int, int, int) method of com.apple.MacOS.AppleEvent */
private static Constructor appleEventConstructor;
/** The <init>(String) method of com.apple.MacOS.AEDesc */
private static Constructor aeDescConstructor;
/** The findFolder method of com.apple.mrj.MRJFileUtils */
private static Method findFolder;
/** The getFileCreator method of com.apple.mrj.MRJFileUtils */
private static Method getFileCreator;
/** The getFileType method of com.apple.mrj.MRJFileUtils */
private static Method getFileType;
/** The openURL method of com.apple.mrj.MRJFileUtils */
private static Method openURL;
/** The makeOSType method of com.apple.MacOS.OSUtils */
private static Method makeOSType;
/** The putParameter method of com.apple.MacOS.AppleEvent */
private static Method putParameter;
/** The sendNoReply method of com.apple.MacOS.AppleEvent */
private static Method sendNoReply;
/** Actually an MRJOSType pointing to the System Folder on a Macintosh */
private static Object kSystemFolderType;
/** The keyDirectObject AppleEvent parameter type */
private static Integer keyDirectObject;
/** The kAutoGenerateReturnID AppleEvent code */
private static Integer kAutoGenerateReturnID;
/** The kAnyTransactionID AppleEvent code */
private static Integer kAnyTransactionID;
/** The linkage object required for JDirect 3 on Mac OS X. */
private static Object linkage;
/** The framework to reference on Mac OS X */
private static final String JDirect_MacOSX = "/System/Library/Frameworks/Carbon.framework/Frameworks/HIToolbox.framework/HIToolbox";
/** JVM constant for MRJ 2.0 */
private static final int MRJ_2_0 = 0;
/** JVM constant for MRJ 2.1 or later */
private static final int MRJ_2_1 = 1;
/** JVM constant for Java on Mac OS X 10.0 (MRJ 3.0) */
private static final int MRJ_3_0 = 3;
/** JVM constant for MRJ 3.1 */
private static final int MRJ_3_1 = 4;
/** JVM constant for any Windows NT JVM */
private static final int WINDOWS_NT = 5;
/** JVM constant for any Windows 9x JVM */
private static final int WINDOWS_9x = 6;
/** JVM constant for any other platform */
private static final int OTHER = -1;
/**
* The file type of the Finder on a Macintosh. Hardcoding "Finder" would keep non-U.S. English
* systems from working properly.
*/
private static final String FINDER_TYPE = "FNDR";
/**
* The creator code of the Finder on a Macintosh, which is needed to send AppleEvents to the
* application.
*/
private static final String FINDER_CREATOR = "MACS";
/** The name for the AppleEvent type corresponding to a GetURL event. */
private static final String GURL_EVENT = "GURL";
/**
* The first parameter that needs to be passed into Runtime.exec() to open the default web
* browser on Windows.
*/
private static final String FIRST_WINDOWS_PARAMETER = "/c";
/** The second parameter for Runtime.exec() on Windows. */
private static final String SECOND_WINDOWS_PARAMETER = "start";
/**
* The third parameter for Runtime.exec() on Windows. This is a "title"
* parameter that the command line expects. Setting this parameter allows
* URLs containing spaces to work.
*/
private static final String THIRD_WINDOWS_PARAMETER = "\"\"";
/**
* The shell parameters for Netscape that opens a given URL in an already-open copy of Netscape
* on many command-line systems.
*/
private static final String NETSCAPE_REMOTE_PARAMETER = "-remote";
private static final String NETSCAPE_OPEN_PARAMETER_START = "openURL(";
private static final String NETSCAPE_OPEN_NEW_WINDOW = ", new-window";
private static final String NETSCAPE_OPEN_PARAMETER_END = ")";
/**
* The message from any exception thrown throughout the initialization process.
*/
private static String errorMessage;
/**
* An initialization block that determines the operating system and loads the necessary
* runtime data.
*/
static
{
loadedWithoutErrors = true;
String osName = System.getProperty("os.name");
if (osName.startsWith("Mac OS"))
{
String mrjVersion = System.getProperty("mrj.version");
String majorMRJVersion = mrjVersion.substring(0, 3);
try
{
double version = Double.valueOf(majorMRJVersion).doubleValue();
if (version == 2)
{
jvm = MRJ_2_0;
}
else if ( (version >= 2.1) && (version < 3))
{
// Assume that all 2.x versions of MRJ work the same. MRJ 2.1 actually
// works via Runtime.exec() and 2.2 supports that but has an openURL() method
// as well that we currently ignore.
jvm = MRJ_2_1;
}
else if (version == 3.0)
{
jvm = MRJ_3_0;
}
else if (version >= 3.1)
{
// Assume that all 3.1 and later versions of MRJ work the same.
jvm = MRJ_3_1;
}
else
{
loadedWithoutErrors = false;
errorMessage = "Unsupported MRJ version: " + version;
}
}
catch (NumberFormatException nfe)
{
loadedWithoutErrors = false;
errorMessage = "Invalid MRJ version: " + mrjVersion;
}
}
else if (osName.startsWith("Windows"))
{
if (osName.indexOf("9") != -1)
{
jvm = WINDOWS_9x;
}
else
{
jvm = WINDOWS_NT;
}
}
else
{
jvm = OTHER;
}
if (loadedWithoutErrors)
{ // if we haven't hit any errors yet
loadedWithoutErrors = loadClasses();
}
}
/**
* This class should be never be instantiated; this just ensures so.
*/
private BrowserLauncher()
{
}
/**
* Called by a static initializer to load any classes, fields, and methods required at runtime
* to locate the user's web browser.
* @return true if all intialization succeeded
* false if any portion of the initialization failed
*/
private static boolean loadClasses()
{
switch (jvm)
{
case MRJ_2_0:
try
{
Class aeTargetClass = Class.forName("com.apple.MacOS.AETarget");
Class osUtilsClass = Class.forName("com.apple.MacOS.OSUtils");
Class appleEventClass = Class.forName(
"com.apple.MacOS.AppleEvent");
Class aeClass = Class.forName("com.apple.MacOS.ae");
aeDescClass = Class.forName("com.apple.MacOS.AEDesc");
aeTargetConstructor = aeTargetClass.getDeclaredConstructor(new Class[]
{
int.class
});
appleEventConstructor = appleEventClass.getDeclaredConstructor(new
Class[]
{
int.class, int.class, aeTargetClass, int.class,
int.class
});
aeDescConstructor = aeDescClass.getDeclaredConstructor(new Class[]
{
String.class
});
makeOSType = osUtilsClass.getDeclaredMethod("makeOSType",
new Class[]
{String.class});
putParameter = appleEventClass.getDeclaredMethod("putParameter",
new Class[]
{int.class, aeDescClass});
sendNoReply = appleEventClass.getDeclaredMethod("sendNoReply",
new Class[]
{});
Field keyDirectObjectField = aeClass.getDeclaredField(
"keyDirectObject");
keyDirectObject = (Integer) keyDirectObjectField.get(null);
Field autoGenerateReturnIDField = appleEventClass.getDeclaredField(
"kAutoGenerateReturnID");
kAutoGenerateReturnID = (Integer) autoGenerateReturnIDField.get(null);
Field anyTransactionIDField = appleEventClass.getDeclaredField(
"kAnyTransactionID");
kAnyTransactionID = (Integer) anyTransactionIDField.get(null);
}
catch (ClassNotFoundException cnfe)
{
errorMessage = cnfe.getMessage();
return false;
}
catch (NoSuchMethodException nsme)
{
errorMessage = nsme.getMessage();
return false;
}
catch (NoSuchFieldException nsfe)
{
errorMessage = nsfe.getMessage();
return false;
}
catch (IllegalAccessException iae)
{
errorMessage = iae.getMessage();
return false;
}
break
;
case MRJ_2_1:
try
{
mrjFileUtilsClass = Class.forName("com.apple.mrj.MRJFileUtils");
mrjOSTypeClass = Class.forName("com.apple.mrj.MRJOSType");
Field systemFolderField = mrjFileUtilsClass.getDeclaredField(
"kSystemFolderType");
kSystemFolderType = systemFolderField.get(null);
findFolder = mrjFileUtilsClass.getDeclaredMethod("findFolder",
new Class[]
{mrjOSTypeClass});
getFileCreator = mrjFileUtilsClass.getDeclaredMethod("getFileCreator",
new Class[]
{File.class});
getFileType = mrjFileUtilsClass.getDeclaredMethod("getFileType",
new Class[]
{File.class});
}
catch (ClassNotFoundException cnfe)
{
errorMessage = cnfe.getMessage();
return false;
}
catch (NoSuchFieldException nsfe)
{
errorMessage = nsfe.getMessage();
return false;
}
catch (NoSuchMethodException nsme)
{
errorMessage = nsme.getMessage();
return false;
}
catch (SecurityException se)
{
errorMessage = se.getMessage();
return false;
}
catch (IllegalAccessException iae)
{
errorMessage = iae.getMessage();
return false;
}
break
;
case MRJ_3_0:
try
{
Class linker = Class.forName("com.apple.mrj.jdirect.Linker");
Constructor constructor = linker.getConstructor(new Class[]
{
Class.class
});
linkage = constructor.newInstance(new Object[]
{
BrowserLauncher.class
});
}
catch (ClassNotFoundException cnfe)
{
errorMessage = cnfe.getMessage();
return false;
}
catch (NoSuchMethodException nsme)
{
errorMessage = nsme.getMessage();
return false;
}
catch (InvocationTargetException ite)
{
errorMessage = ite.getMessage();
return false;
}
catch (InstantiationException ie)
{
errorMessage = ie.getMessage();
return false;
}
catch (IllegalAccessException iae)
{
errorMessage = iae.getMessage();
return false;
}
break
;
case MRJ_3_1:
try
{
mrjFileUtilsClass = Class.forName("com.apple.mrj.MRJFileUtils");
openURL = mrjFileUtilsClass.getDeclaredMethod("openURL",
new Class[]
{String.class});
}
catch (ClassNotFoundException cnfe)
{
errorMessage = cnfe.getMessage();
return false;
}
catch (NoSuchMethodException nsme)
{
errorMessage = nsme.getMessage();
return false;
}
break
;
default:
break;
}
return true;
}
/**
* Attempts to locate the default web browser on the local system. s results so it
* only locates the browser once for each use of this class per JVM instance.
* @return The browser for the system. Note that this may not be what you would consider
* to be a standard web browser; instead, it's the application that gets called to
* open the default web browser. In some cases, this will be a non-String object
* that provides the means of calling the default browser.
*/
private static Object locateBrowser()
{
if (browser != null)
{
return browser;
}
switch (jvm)
{
case MRJ_2_0:
try
{
Integer finderCreatorCode = (Integer) makeOSType.invoke(null,
new Object[]
{FINDER_CREATOR});
Object aeTarget = aeTargetConstructor.newInstance(new Object[]
{
finderCreatorCode
});
Integer gurlType = (Integer) makeOSType.invoke(null,
new Object[]
{GURL_EVENT});
Object appleEvent = appleEventConstructor.newInstance(new Object[]
{
gurlType, gurlType, aeTarget, kAutoGenerateReturnID,
kAnyTransactionID
});
// Don't set browser = appleEvent because then the next time we call
// locateBrowser(), we'll get the same AppleEvent, to which we'll already have
// added the relevant parameter. Instead, regenerate the AppleEvent every time.
// There's probably a way to do this better; if any has any ideas, please let
// me know.
return appleEvent;
}
catch (IllegalAccessException iae)
{
browser = null;
errorMessage = iae.getMessage();
return browser;
}
catch (InstantiationException ie)
{
browser = null;
errorMessage = ie.getMessage();
return browser;
}
catch (InvocationTargetException ite)
{
browser = null;
errorMessage = ite.getMessage();
return browser;
}
case MRJ_2_1:
File systemFolder;
try
{
systemFolder = (File) findFolder.invoke(null,
new Object[]
{kSystemFolderType});
}
catch (IllegalArgumentException iare)
{
browser = null;
errorMessage = iare.getMessage();
return browser;
}
catch (IllegalAccessException iae)
{
browser = null;
errorMessage = iae.getMessage();
return browser;
}
catch (InvocationTargetException ite)
{
browser = null;
errorMessage = ite.getTargetException().getClass() + ": " +
ite.getTargetException().getMessage();
return browser;
}
String[] systemFolderFiles = systemFolder.list();
// Avoid a FilenameFilter because that can't be stopped mid-list
for (int i = 0; i < systemFolderFiles.length; i++)
{
try
{
File file = new File(systemFolder, systemFolderFiles[i]);
if (!file.isFile())
{
continue;
}
// We're looking for a file with a creator code of 'MACS' and
// a type of 'FNDR'. Only requiring the type results in non-Finder
// applications being picked up on certain Mac OS 9 systems,
// especially German ones, and sending a GURL event to those
// applications results in a logout under Multiple Users.
Object fileType = getFileType.invoke(null,
new Object[]
{file});
if (FINDER_TYPE.equals(fileType.toString()))
{
Object fileCreator = getFileCreator.invoke(null,
new Object[]
{file});
if (FINDER_CREATOR.equals(fileCreator.toString()))
{
browser = file.toString(); // Actually the Finder, but that's OK
return browser;
}
}
}
catch (IllegalArgumentException iare)
{
errorMessage = iare.getMessage();
return null;
}
catch (IllegalAccessException iae)
{
browser = null;
errorMessage = iae.getMessage();
return browser;
}
catch (InvocationTargetException ite)
{
browser = null;
errorMessage = ite.getTargetException().getClass() + ": " +
ite.getTargetException().getMessage();
return browser;
}
}
browser = null;
break;
case MRJ_3_0:
case MRJ_3_1:
browser = ""; // Return something non-null
break;
case WINDOWS_NT:
browser = "cmd.exe";
break;
case WINDOWS_9x:
browser = "command.com";
break;
case OTHER:
default:
browser = jalview.bin.Cache.getDefault("DEFAULT_BROWSER", "firefox");
break;
}
return browser;
}
/**
* used to ensure that browser is up-to-date after a configuration
* change (Unix DEFAULT_BROWSER property change).
*/
public static void resetBrowser() {
browser = null;
}
/**
* Attempts to open the default web browser to the given URL.
* @param url The URL to open
* @throws IOException If the web browser could not be located or does not run
*/
public static void openURL(String url)
throws IOException
{
if (!loadedWithoutErrors)
{
throw new IOException("Exception in finding browser: " +
errorMessage);
}
Object browser = locateBrowser();
if (browser == null)
{
throw new IOException("Unable to locate browser: " + errorMessage);
}
switch (jvm)
{
case MRJ_2_0:
Object aeDesc = null;
try
{
aeDesc = aeDescConstructor.newInstance(new Object[]
{url});
putParameter.invoke(browser,
new Object[]
{keyDirectObject, aeDesc});
sendNoReply.invoke(browser, new Object[]
{});
}
catch (InvocationTargetException ite)
{
throw new IOException(
"InvocationTargetException while creating AEDesc: " +
ite.getMessage());
}
catch (IllegalAccessException iae)
{
throw new IOException(
"IllegalAccessException while building AppleEvent: " +
iae.getMessage());
}
catch (InstantiationException ie)
{
throw new IOException(
"InstantiationException while creating AEDesc: " +
ie.getMessage());
}
finally
{
aeDesc = null; // Encourage it to get disposed if it was created
browser = null; // Ditto
}
break;
case MRJ_2_1:
Runtime.getRuntime().exec(new String[]
{ (String) browser, url});
break;
case MRJ_3_0:
int[] instance = new int[1];
int result = ICStart(instance, 0);
if (result == 0)
{
int[] selectionStart = new int[]
{
0};
byte[] urlBytes = url.getBytes();
int[] selectionEnd = new int[]
{
urlBytes.length};
result = ICLaunchURL(instance[0], new byte[]
{0}, urlBytes,
urlBytes.length, selectionStart, selectionEnd);
if (result == 0)
{
// Ignore the return value; the URL was launched successfully
// regardless of what happens here.
ICStop(instance);
}
else
{
throw new IOException("Unable to launch URL: " + result);
}
}
else
{
throw new IOException(
"Unable to create an Internet Config instance: " + result);
}
break;
case MRJ_3_1:
try
{
openURL.invoke(null, new Object[]
{url});
}
catch (InvocationTargetException ite)
{
throw new IOException(
"InvocationTargetException while calling openURL: " +
ite.getMessage());
}
catch (IllegalAccessException iae)
{
throw new IOException(
"IllegalAccessException while calling openURL: " +
iae.getMessage());
}
break
;
case WINDOWS_NT:
case WINDOWS_9x:
// Add quotes around the URL to allow ampersands and other special
// characters to work.
Process process = Runtime.getRuntime().exec(new String[]
{
(String) browser, FIRST_WINDOWS_PARAMETER,
SECOND_WINDOWS_PARAMETER, THIRD_WINDOWS_PARAMETER,
'"' + url + '"'
});
// This avoids a memory leak on some versions of Java on Windows.
// That's hinted at in