java.lang.Object
- org.astrogrid.samp.gui.BrowserLauncher

```
class BrowserLauncher
extends java.lang.Object
```
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

Version:

1.4b1 (Released June 20, 2001)

Author:

Eric Albert (ejalbert@cs.stanford.edu)

Field Summary

Fields
Modifier and Type	Field	Description
`private static java.lang.Class`	`aeDescClass`	The com.apple.MacOS.AEDesc class
`private static java.lang.reflect.Constructor`	`aeDescConstructor`	The (String) method of com.apple.MacOS.AEDesc
`private static java.lang.reflect.Constructor`	`aeTargetConstructor`	The (int) method of com.apple.MacOS.AETarget
`private static java.lang.reflect.Constructor`	`appleEventConstructor`	The (int, int, int) method of com.apple.MacOS.AppleEvent
`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

Constructor Summary

Constructors
Modifier Constructor Description

private BrowserLauncher()
This class should be never be instantiated; this just ensures so.

Method Summary

All Methods Static Methods Concrete Methods
Modifier and Type	Method	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.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - jvm
```
private static int jvm
```
    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.
  - browser
```
private static java.lang.Object browser
```
    The browser for the system
  - loadedWithoutErrors
```
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.
    Note that if this is false, openURL() will always return an IOException.
  - mrjFileUtilsClass
```
private static java.lang.Class mrjFileUtilsClass
```
    The com.apple.mrj.MRJFileUtils class
  - mrjOSTypeClass
```
private static java.lang.Class mrjOSTypeClass
```
    The com.apple.mrj.MRJOSType class
  - aeDescClass
```
private static java.lang.Class aeDescClass
```
    The com.apple.MacOS.AEDesc class
  - aeTargetConstructor
```
private static java.lang.reflect.Constructor aeTargetConstructor
```
    The (int) method of com.apple.MacOS.AETarget
  - appleEventConstructor
```
private static java.lang.reflect.Constructor appleEventConstructor
```
    The (int, int, int) method of com.apple.MacOS.AppleEvent
  - aeDescConstructor
```
private static java.lang.reflect.Constructor aeDescConstructor
```
    The (String) method of com.apple.MacOS.AEDesc
  - findFolder
```
private static java.lang.reflect.Method findFolder
```
    The findFolder method of com.apple.mrj.MRJFileUtils
  - getFileCreator
```
private static java.lang.reflect.Method getFileCreator
```
    The getFileCreator method of com.apple.mrj.MRJFileUtils
  - getFileType
```
private static java.lang.reflect.Method getFileType
```
    The getFileType method of com.apple.mrj.MRJFileUtils
  - openURL
```
private static java.lang.reflect.Method openURL
```
    The openURL method of com.apple.mrj.MRJFileUtils
  - makeOSType
```
private static java.lang.reflect.Method makeOSType
```
    The makeOSType method of com.apple.MacOS.OSUtils
  - putParameter
```
private static java.lang.reflect.Method putParameter
```
    The putParameter method of com.apple.MacOS.AppleEvent
  - sendNoReply
```
private static java.lang.reflect.Method sendNoReply
```
    The sendNoReply method of com.apple.MacOS.AppleEvent
  - kSystemFolderType
```
private static java.lang.Object kSystemFolderType
```
    Actually an MRJOSType pointing to the System Folder on a Macintosh
  - keyDirectObject
```
private static java.lang.Integer keyDirectObject
```
    The keyDirectObject AppleEvent parameter type
  - kAutoGenerateReturnID
```
private static java.lang.Integer kAutoGenerateReturnID
```
    The kAutoGenerateReturnID AppleEvent code
  - kAnyTransactionID
```
private static java.lang.Integer kAnyTransactionID
```
    The kAnyTransactionID AppleEvent code
  - linkage
```
private static java.lang.Object linkage
```
    The linkage object required for JDirect 3 on Mac OS X.
  - JDirect_MacOSX
```
private static final java.lang.String JDirect_MacOSX
```
    The framework to reference on Mac OS X
    
    See Also:
    
    Constant Field Values
  - MRJ_2_0
```
private static final int MRJ_2_0
```
    JVM constant for MRJ 2.0
    
    See Also:
    
    Constant Field Values
  - MRJ_2_1
```
private static final int MRJ_2_1
```
    JVM constant for MRJ 2.1 or later
    
    See Also:
    
    Constant Field Values
  - MRJ_3_0
```
private static final int MRJ_3_0
```
    JVM constant for Java on Mac OS X 10.0 (MRJ 3.0)
    
    See Also:
    
    Constant Field Values
  - MRJ_3_1
```
private static final int MRJ_3_1
```
    JVM constant for MRJ 3.1
    
    See Also:
    
    Constant Field Values
  - WINDOWS_NT
```
private static final int WINDOWS_NT
```
    JVM constant for any Windows NT JVM
    
    See Also:
    
    Constant Field Values
  - WINDOWS_9x
```
private static final int WINDOWS_9x
```
    JVM constant for any Windows 9x JVM
    
    See Also:
    
    Constant Field Values
  - OTHER
```
private static final int OTHER
```
    JVM constant for any other platform
    
    See Also:
    
    Constant Field Values
  - FINDER_TYPE
```
private static final java.lang.String FINDER_TYPE
```
    The file type of the Finder on a Macintosh. Hardcoding "Finder" would keep non-U.S. English systems from working properly.
    
    See Also:
    
    Constant Field Values
  - FINDER_CREATOR
```
private static final java.lang.String FINDER_CREATOR
```
    The creator code of the Finder on a Macintosh, which is needed to send AppleEvents to the application.
    
    See Also:
    
    Constant Field Values
  - GURL_EVENT
```
private static final java.lang.String GURL_EVENT
```
    The name for the AppleEvent type corresponding to a GetURL event.
    
    See Also:
    
    Constant Field Values
  - FIRST_WINDOWS_PARAMETER
```
private static final 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.
    
    See Also:
    
    Constant Field Values
  - SECOND_WINDOWS_PARAMETER
```
private static final java.lang.String SECOND_WINDOWS_PARAMETER
```
    The second parameter for Runtime.exec() on Windows.
    
    See Also:
    
    Constant Field Values
  - THIRD_WINDOWS_PARAMETER
```
private static final java.lang.String THIRD_WINDOWS_PARAMETER
```
    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.
    
    See Also:
    
    Constant Field Values
  - NETSCAPE_REMOTE_PARAMETER
```
private static final 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.
    
    See Also:
    
    Constant Field Values
  - NETSCAPE_OPEN_PARAMETER_START
```
private static final java.lang.String NETSCAPE_OPEN_PARAMETER_START
```
    See Also:
    
    Constant Field Values
  - NETSCAPE_OPEN_PARAMETER_END
```
private static final java.lang.String NETSCAPE_OPEN_PARAMETER_END
```
    See Also:
    
    Constant Field Values
  - errorMessage
```
private static java.lang.String errorMessage
```
    The message from any exception thrown throughout the initialization process.
- Constructor Detail
  - BrowserLauncher
```
private BrowserLauncher()
```
    This class should be never be instantiated; this just ensures so.
- Method Detail
  - loadClasses
```
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.
    
    Returns:
    
    true if all intialization succeeded false if any portion of the initialization failed
  - locateBrowser
```
private static java.lang.Object locateBrowser()
```
    Attempts to locate the default web browser on the local system. Caches results so it only locates the browser once for each use of this class per JVM instance.
    
    Returns:
    
    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.
  - openURL
```
public static void openURL(java.lang.String url)
                    throws java.io.IOException
```
    Attempts to open the default web browser to the given URL.
    
    Parameters:
    
    url - The URL to open
    
    Throws:
    
    java.io.IOException - If the web browser could not be located or does not run
  - ICStart
```
private static int ICStart(int[] instance,
                           int signature)
```
    Methods required for Mac OS X. The presence of native methods does not cause any problems on other platforms.
  - ICStop
```
private static int ICStop(int[] instance)
```
  - ICLaunchURL
```
private static int ICLaunchURL(int instance,
                               byte[] hint,
                               byte[] data,
                               int len,
                               int[] selectionStart,
                               int[] selectionEnd)
```

Class BrowserLauncher

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

jvm

browser

loadedWithoutErrors

mrjFileUtilsClass

mrjOSTypeClass

aeDescClass

aeTargetConstructor

appleEventConstructor

aeDescConstructor

findFolder

getFileCreator

getFileType

openURL

makeOSType

putParameter

sendNoReply

kSystemFolderType

keyDirectObject

kAutoGenerateReturnID

kAnyTransactionID

linkage

JDirect_MacOSX

MRJ_2_0

MRJ_2_1

MRJ_3_0

MRJ_3_1

WINDOWS_NT

WINDOWS_9x

OTHER

FINDER_TYPE

FINDER_CREATOR

GURL_EVENT

FIRST_WINDOWS_PARAMETER

SECOND_WINDOWS_PARAMETER

THIRD_WINDOWS_PARAMETER

NETSCAPE_REMOTE_PARAMETER

NETSCAPE_OPEN_PARAMETER_START

NETSCAPE_OPEN_PARAMETER_END

errorMessage

Constructor Detail

BrowserLauncher

Method Detail

loadClasses

locateBrowser

openURL

ICStart

ICStop

ICLaunchURL