package jipe;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.lang.reflect.Constructor;
import java.lang.reflect.Field;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
/**
* 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.
* <p>
* 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.
* <p>
* Anyway, this code is completely in Java and will run on all JDK 1.1(or better)-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.
* <p>
* 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.
* <p>
* This code is Copyright 1999 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.
* <p>
* Credits:
* <br>Steven Spencer, JavaWorld magazine (<a href="http://www.javaworld.com/javaworld/javatips/jw-javatip66.html">Java Tip 66</a>)
* <br>Ron B. Yeh, ZeroG
* <br>Ben Engber, The New York Times
* <br>Paul Teitlebaum and Andrea Cantatore, Datatech Software
*
* @author Eric Albert (<a href="mailto:ejalbert@cs.stanford.edu">ejalbert@cs.stanford.edu</a>)
* @version 1.2 (Released July 28, 1999)
*/
/* Fixed a minor bug that kept browser from launching on Solaris (NETSCAPE_OPEN_PARAMETER_START doesn't work with "'")
* and added main class driver so that changes could be easily checked. Haven't verified against other Unix flavors.
* Aaron Miller (<a href="mailto:aaronmiller@hotmail.com">aaronmiller@hotmail.com</a>)
*/
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.
* <p>
* Note that if this is <code>false</code>, <code>openURL()</code> 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.MacOSError class */
private static Class macOSErrorClass;
/** 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 getFileType method of com.apple.mrj.MRJOSType */
private static Method getFileType;
/** 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;
/** 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 any Windows 9x JVM */
private static final int WINDOWS_9x = 2;
/** JVM constant for any Windows NT JVM */
private static final int WINDOWS_NT = 3;
/** 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 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_OPEN_PARAMETER_START = " -remote openURL(";
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 ("Mac OS".equals(osName))
{
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)
{
// For the time being, assume that all post-2.0 versions of MRJ work the same
jvm = MRJ_2_1;
}
else
{
loadedWithoutErrors = false;
errorMessage = "Unsupported MRJ version: " + version;
}
}
catch (NumberFormatException nfe)
{
loadedWithoutErrors = false;
errorMessage = "Invalid MRJ version: " + mrjVersion;
}
}
else if (osName.startsWith("Windows"))
{ //still needs verification against Win2K
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 <code>true</code> if all intialization succeeded
* <code>false</code> 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");
macOSErrorClass = Class.forName("com.apple.MacOS.MacOSError");
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 });
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;
}
return true;
}
/**
* 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.
* @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;
}
Object fileType = getFileType.invoke(null,
new Object[]{ file });
if (FINDER_TYPE.equals(fileType.toString()))
{
browser = file.toString(); // Actually the Finder, but that's OK
return browser;
}
}
catch (IllegalArgumentException iare)
{
browser = browser;
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 WINDOWS_NT:
browser = "cmd.exe";
break;
case WINDOWS_9x:
browser = "command.com";
break;
case OTHER: //fall through
default:
browser = "netscape";
break;
}
return browser;
}
/**
* 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 WINDOWS_NT://fall through
case WINDOWS_9x:
Runtime.getRuntime().exec( new String[]{ (String) browser,
FIRST_WINDOWS_PARAMETER,
SECOND_WINDOWS_PARAMETER, url });
break;
case OTHER:
// Assume that we're on Unix and that Netscape is installed
// First, attempt to open the URL in a currently running session of Netscape
Process process =
Runtime.getRuntime().exec((String) browser +
NETSCAPE_OPEN_PARAMETER_START + url +
NETSCAPE_OPEN_PARAMETER_END);
try
{
int exitCode = process.waitFor();
if (exitCode != 0)
{ // if Netscape was not open
Runtime.getRuntime().exec(
new String[]{ (String) browser, url });
}
}
catch (InterruptedException ie)
{
throw new IOException(
"InterruptedException while launching browser: " +
ie.getMessage());
}
break;
default:
// This should never occur, but if it does, we'll try the simplest thing possible
Runtime.getRuntime().exec(
new String[]{ (String) browser, url });
break;
}
}
// Driver to test class
public static void main(String[] args) throws IOException
{
if (args.length != 1)
openURL("http://java.sun.com");
else
openURL(args[0]);
}
}