/*
* This code is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This code is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this program; if not, write to the Free
* Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
* MA 02111-1307, USA.
*/
//package no.geosoft.cc.io;
/**
* Browser 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-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 1999-2001 by Eric Albert ([email protected])
* 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.
* <p>
* Credits:
* <br>Steven Spencer, JavaWorld magazine
* (<a href="http://www.javaworld.com/javaworld/javatips/jw-javatip66.html">
* Java Tip 66</a>)
* <br>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 (<a href="mailto:[email protected]">
* [email protected]</a>)
* @version 1.4b1 (Released June 20, 2001)
*
* @author <a href="mailto:[email protected]">Jacob Dreyer</a>
* Added methods to the API and adjusted the linux version slightly.
*/ public class Browser {
/**
* 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.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_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 Browser() {}
/**
* 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"); 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");
/**
* 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.
// Avoid a FilenameFilter because that can't be stopped mid-list
String[] systemFolderFiles = systemFolder.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())) {
// Actually the Finder, but that's OK
browser = file.toString(); 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 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 = "netscape"; break;
}
return browser;
}
/**
* Open the specified file in the client web browser.
*
* @param file File to open
* @throws IOException If there is brwoser problem.
*
*/ public static void openUrl (File file) throws IOException
{
openUrl ("file://" + file.getPath());
}
/**
* Open the specified URL in the client web browser.
*
* @param url URL to open.
* @throws IOException If there is brwoser problem.
*/ public static void openUrl (URL url) throws IOException
{
openUrl (url.toString());
}
/**
* Open the specified URL in the client web browser.
*
* @param url URL to open.
* @throws IOException If there is brwoser problem.
*/ 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_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 <http://developer.java.sun.com/developer/qow/
// archive/68/>. try {
process.waitFor();
process.exitValue();
} catch (InterruptedException ie) { throw new IOException("InterruptedException while launching browser: " + ie.getMessage());
} 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
String command = browser.toString() + " -raise " +
NETSCAPE_REMOTE_PARAMETER + " " +
NETSCAPE_OPEN_PARAMETER_START +
url + NETSCAPE_OPEN_PARAMETER_END;
process = Runtime.getRuntime().exec (command);
try { int exitCode = process.waitFor(); if (exitCode != 0) { // if Netscape was not open
Runtime.getRuntime().exec(new String[] { (String) browser, url });
}
} catch (InterruptedException exception) {
exception.printStackTrace(); throw new IOException("InterruptedException while launching browser: " + exception.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;
}
}
/**
* Methods required for Mac OS X. The presence of native methods does not
* cause any problems on other platforms.
*/ private native static int ICStart (int[] instance, int signature); private native static int ICStop (int[] instance); private native static int ICLaunchURL (int instance, byte[] hint, byte[]
data, int len, int[] selectionStart, int[] selectionEnd);
}
