class BrowserLauncher
extends java.lang.Object
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
Modifier and Type | Field and Description |
---|---|
private static java.lang.Class |
aeDescClass
The com.apple.MacOS.AEDesc class
|
private static java.lang.reflect.Constructor |
aeDescConstructor
The
|
private static java.lang.reflect.Constructor |
aeTargetConstructor
The
|
private static java.lang.reflect.Constructor |
appleEventConstructor
The
|
private static java.lang.Object |
browser
The browser for the system
|
private static java.lang.String |
errorMessage
The message from any exception thrown throughout the initialization process.
|
private static java.lang.String |
FINDER_CREATOR
The creator code of the Finder on a Macintosh, which is needed to send AppleEvents to the
application.
|
private static java.lang.String |
FINDER_TYPE
The file type of the Finder on a Macintosh.
|
private static java.lang.reflect.Method |
findFolder
The findFolder method of com.apple.mrj.MRJFileUtils
|
private static java.lang.String |
FIRST_WINDOWS_PARAMETER
The first parameter that needs to be passed into Runtime.exec() to open the default web
browser on Windows.
|
private static java.lang.reflect.Method |
getFileCreator
The getFileCreator method of com.apple.mrj.MRJFileUtils
|
private static java.lang.reflect.Method |
getFileType
The getFileType method of com.apple.mrj.MRJFileUtils
|
private static java.lang.String |
GURL_EVENT
The name for the AppleEvent type corresponding to a GetURL event.
|
private static java.lang.String |
JDirect_MacOSX
The framework to reference on Mac OS X
|
private static int |
jvm
The Java virtual machine that we are running on.
|
private static java.lang.Integer |
kAnyTransactionID
The kAnyTransactionID AppleEvent code
|
private static java.lang.Integer |
kAutoGenerateReturnID
The kAutoGenerateReturnID AppleEvent code
|
private static java.lang.Integer |
keyDirectObject
The keyDirectObject AppleEvent parameter type
|
private static java.lang.Object |
kSystemFolderType
Actually an MRJOSType pointing to the System Folder on a Macintosh
|
private static java.lang.Object |
linkage
The linkage object required for JDirect 3 on Mac OS X.
|
private static boolean |
loadedWithoutErrors
Caches 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 java.lang.reflect.Method |
makeOSType
The makeOSType method of com.apple.MacOS.OSUtils
|
private static int |
MRJ_2_0
JVM constant for MRJ 2.0
|
private static int |
MRJ_2_1
JVM constant for MRJ 2.1 or later
|
private static int |
MRJ_3_0
JVM constant for Java on Mac OS X 10.0 (MRJ 3.0)
|
private static int |
MRJ_3_1
JVM constant for MRJ 3.1
|
private static java.lang.Class |
mrjFileUtilsClass
The com.apple.mrj.MRJFileUtils class
|
private static java.lang.Class |
mrjOSTypeClass
The com.apple.mrj.MRJOSType class
|
private static java.lang.String |
NETSCAPE_OPEN_PARAMETER_END |
private static java.lang.String |
NETSCAPE_OPEN_PARAMETER_START |
private static java.lang.String |
NETSCAPE_REMOTE_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 java.lang.reflect.Method |
openURL
The openURL method of com.apple.mrj.MRJFileUtils
|
private static int |
OTHER
JVM constant for any other platform
|
private static java.lang.reflect.Method |
putParameter
The putParameter method of com.apple.MacOS.AppleEvent
|
private static java.lang.String |
SECOND_WINDOWS_PARAMETER
The second parameter for Runtime.exec() on Windows.
|
private static java.lang.reflect.Method |
sendNoReply
The sendNoReply method of com.apple.MacOS.AppleEvent
|
private static java.lang.String |
THIRD_WINDOWS_PARAMETER
The third parameter for Runtime.exec() on Windows.
|
private static int |
WINDOWS_9x
JVM constant for any Windows 9x JVM
|
private static int |
WINDOWS_NT
JVM constant for any Windows NT JVM
|
Modifier | Constructor and Description |
---|---|
private |
BrowserLauncher()
This class should be never be instantiated; this just ensures so.
|
Modifier and Type | Method and Description |
---|---|
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 java.lang.Object |
locateBrowser()
Attempts to locate the default web browser on the local system.
|
static void |
openURL(java.lang.String url)
Attempts to open the default web browser to the given URL.
|
private static int jvm
private static java.lang.Object browser
private static boolean loadedWithoutErrors
Note that if this is false
, openURL()
will always return an
IOException.
private static java.lang.Class mrjFileUtilsClass
private static java.lang.Class mrjOSTypeClass
private static java.lang.Class aeDescClass
private static java.lang.reflect.Constructor aeTargetConstructor
private static java.lang.reflect.Constructor appleEventConstructor
private static java.lang.reflect.Constructor aeDescConstructor
private static java.lang.reflect.Method findFolder
private static java.lang.reflect.Method getFileCreator
private static java.lang.reflect.Method getFileType
private static java.lang.reflect.Method openURL
private static java.lang.reflect.Method makeOSType
private static java.lang.reflect.Method putParameter
private static java.lang.reflect.Method sendNoReply
private static java.lang.Object kSystemFolderType
private static java.lang.Integer keyDirectObject
private static java.lang.Integer kAutoGenerateReturnID
private static java.lang.Integer kAnyTransactionID
private static java.lang.Object linkage
private static final java.lang.String JDirect_MacOSX
private static final int MRJ_2_0
private static final int MRJ_2_1
private static final int MRJ_3_0
private static final int MRJ_3_1
private static final int WINDOWS_NT
private static final int WINDOWS_9x
private static final int OTHER
private static final java.lang.String FINDER_TYPE
private static final java.lang.String FINDER_CREATOR
private static final java.lang.String GURL_EVENT
private static final java.lang.String FIRST_WINDOWS_PARAMETER
private static final java.lang.String SECOND_WINDOWS_PARAMETER
private static final java.lang.String THIRD_WINDOWS_PARAMETER
private static final java.lang.String NETSCAPE_REMOTE_PARAMETER
private static final java.lang.String NETSCAPE_OPEN_PARAMETER_START
private static final java.lang.String NETSCAPE_OPEN_PARAMETER_END
private static java.lang.String errorMessage
private BrowserLauncher()
private static boolean loadClasses()
true
if all intialization succeeded
false
if any portion of the initialization failedprivate static java.lang.Object locateBrowser()
public static void openURL(java.lang.String url) throws java.io.IOException
url
- The URL to openjava.io.IOException
- If the web browser could not be located or does not runprivate static int ICStart(int[] instance, int signature)
private static int ICStop(int[] instance)
private static int ICLaunchURL(int instance, byte[] hint, byte[] data, int len, int[] selectionStart, int[] selectionEnd)