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BrowserLauncher is a class that provides one static method, openURL, which opens the default web browser for the current user of the system to the given URL. It may support other protocols depending on the system -- mailto, ftp, etc. -- but that has not been rigorously tested and is not guaranteed to work.
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
| Field Summary | |
private static Class | aeDescClassThe com.apple.MacOS.AEDesc class |
private static Constructor | aeDescConstructorThe |
private static Constructor | aeTargetConstructorThe |
private static Constructor | appleEventConstructorThe |
private static Object | browserThe browser for the system |
private static String | errorMessageThe message from any exception thrown throughout the initialization process. |
private final static String | FINDER_CREATORThe creator code of the Finder on a Macintosh, which is needed to send AppleEvents to the application. |
private final static String | FINDER_TYPEThe file type of the Finder on a Macintosh. |
private static Method | findFolderThe findFolder method of com.apple.mrj.MRJFileUtils |
private final static String | FIRST_WINDOWS_PARAMETERThe first parameter that needs to be passed into Runtime.exec() to open the default web browser on Windows. |
private static Method | getFileCreatorThe getFileCreator method of com.apple.mrj.MRJFileUtils |
private static Method | getFileTypeThe getFileType method of com.apple.mrj.MRJFileUtils |
private final static String | GURL_EVENTThe name for the AppleEvent type corresponding to a GetURL event. |
private final static String | JDirect_MacOSXThe framework to reference on Mac OS X |
private static int | jvmThe Java virtual machine that we are running on. |
private static Integer | kAnyTransactionIDThe kAnyTransactionID AppleEvent code |
private static Integer | kAutoGenerateReturnIDThe kAutoGenerateReturnID AppleEvent code |
private static Integer | keyDirectObjectThe keyDirectObject AppleEvent parameter type |
private static Object | kSystemFolderTypeActually an MRJOSType pointing to the System Folder on a Macintosh |
private static Object | linkageThe linkage object required for JDirect 3 on Mac OS X. |
private static boolean | loadedWithoutErrorsCaches whether any classes, methods, and fields that are not part of the JDK and need to be dynamically loaded at runtime loaded successfully. |
private static Method | makeOSTypeThe makeOSType method of com.apple.MacOS.OSUtils |
private final static int | MRJ_2_0JVM constant for MRJ 2.0 |
private final static int | MRJ_2_1JVM constant for MRJ 2.1 or later |
private final static int | MRJ_3_0JVM constant for Java on Mac OS X 10.0 (MRJ 3.0) |
private final static int | MRJ_3_1JVM constant for MRJ 3.1 |
private static Class | mrjFileUtilsClassThe com.apple.mrj.MRJFileUtils class |
private static Class | mrjOSTypeClassThe com.apple.mrj.MRJOSType class |
private final static String | NETSCAPE_OPEN_PARAMETER_END |
private final static String | NETSCAPE_OPEN_PARAMETER_START |
private final static String | NETSCAPE_REMOTE_PARAMETERThe shell parameters for Netscape that opens a given URL in an already-open copy of Netscape on many command-line systems. |
private static Method | openURLThe openURL method of com.apple.mrj.MRJFileUtils |
private final static int | OTHERJVM constant for any other platform |
private static Method | putParameterThe putParameter method of com.apple.MacOS.AppleEvent |
private final static String | SECOND_WINDOWS_PARAMETERThe second parameter for Runtime.exec() on Windows. |
private static Method | sendNoReplyThe sendNoReply method of com.apple.MacOS.AppleEvent |
private final static String | THIRD_WINDOWS_PARAMETERThe third parameter for Runtime.exec() on Windows. |
private final static int | WINDOWS_9xJVM constant for any Windows 9x JVM |
private final static int | WINDOWS_NTJVM constant for any Windows NT JVM |
| Constructor Summary | |
private | BrowserLauncher()This class should be never be instantiated; this just ensures so. |
| Method Summary | |
private static int | ICLaunchURL(int instance, byte[] hint, byte[] data, int len, int[] selectionStart, int[] selectionEnd) |
private static int | ICStart(int[] instance, int signature)Methods required for Mac OS X. |
private static int | ICStop(int[] instance) |
private static boolean | loadClasses()Called by a static initializer to load any classes, fields, and methods required at runtime to locate the user's web browser. |
private static Object | locateBrowser()Attempts to locate the default web browser on the local system. |
static void | openURL(String url)Attempts to open the default web browser to the given URL. |
| Field Detail |
private static Class aeDescClass
private static Constructor aeDescConstructor
private static Constructor aeTargetConstructor
private static Constructor appleEventConstructor
private static Object browser
private static String errorMessage
private final static String FINDER_CREATOR
private final static String FINDER_TYPE
private static Method findFolder
private final static String FIRST_WINDOWS_PARAMETER
private static Method getFileCreator
private static Method getFileType
private final static String GURL_EVENT
private final static String JDirect_MacOSX
private static int jvm
private static Integer kAnyTransactionID
private static Integer kAutoGenerateReturnID
private static Integer keyDirectObject
private static Object kSystemFolderType
private static Object linkage
private static boolean loadedWithoutErrors
Note that if this is false, openURL() will always return an IOException.
private static Method makeOSType
private final static int MRJ_2_0
private final static int MRJ_2_1
private final static int MRJ_3_0
private final static int MRJ_3_1
private static Class mrjFileUtilsClass
private static Class mrjOSTypeClass
private final static String NETSCAPE_OPEN_PARAMETER_END
private final static String NETSCAPE_OPEN_PARAMETER_START
private final static String NETSCAPE_REMOTE_PARAMETER
private static Method openURL
private final static int OTHER
private static Method putParameter
private final static String SECOND_WINDOWS_PARAMETER
private static Method sendNoReply
private final static String THIRD_WINDOWS_PARAMETER
private final static int WINDOWS_9x
private final static int WINDOWS_NT
| Constructor Detail |
private BrowserLauncher()
| Method Detail |
private static int ICLaunchURL(int instance, byte[] hint, byte[] data, int len, int[] selectionStart, int[] selectionEnd)
private static int ICStart(int[] instance, int signature)
private static int ICStop(int[] instance)
private static boolean loadClasses()
true if all intialization succeeded false if any portion of the initialization failedprivate static Object locateBrowser()
public static void openURL(String url)
throws java.io.IOException
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