/* * Copyright (C) 2001 Clarkware Consulting, Inc. * All Rights Reserved. *  * Redistribution and use in source and binary forms, with or without  * modification, are permitted provided that the following conditions  * are met: * *  1. Redistributions of source code must retain the above copyright *     notice, this list of conditions and the following disclaimer. * *  2. Redistributions in binary form must reproduce the above copyright  *     notice, this list of conditions and the following disclaimer in the  *     documentation and/or other materials provided with the distribution. * *  3. Neither the name of Clarkware Consulting, Inc. nor the names of its  *     contributors may be used to endorse or promote products derived  *     from this software without prior written permission. For written  *     permission, please contact clarkware@clarkware.com. * * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED WARRANTIES, * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND * FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL * CLARKWARE CONSULTING OR ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA,  * OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING  * NEGLIGENCE OR OTHERWISE) ARISING IN  ANY WAY OUT OF THE USE OF THIS  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */import java.io.*;import java.net.URL;import java.util.StringTokenizer;/** * <code>JWhich</code> is a utility that takes a Java class name  * and displays the absolute pathname of the class file that would  * be loaded first by the class loader, as prescribed by the * class path. * <p> * <code>JWhich</code> also validates the class path and reports * any non-existent or invalid class path entries. * <p> * Usage is similar to the UNIX <code>which</code> command. * <p> * Example uses: * <p> * <blockquote> * 		To find the absolute pathname of <code>MyClass.class</code> *		not in a package: *		<pre>java JWhich MyClass</pre> * * 		To find the absolute pathname of <code>MyClass.class</code> *		in the <code>my.package</code> package: *		<pre>java JWhich my.package.MyClass</pre> * </blockquote> * * @author <a href="mailto:mike@clarkware.com">Mike Clark</a> * @author <a href="http://www.clarkware.com">Clarkware Consulting, Inc.</a> */public class JWhich {		private static String CLASSPATH;	/**	 * Prints the absolute pathname of the class file 	 * containing the specified class name, as prescribed	 * by the class path.	 *	 * @param className Name of the class.	 */	public static void which(String className) {		URL classUrl = findClass(className);				if (classUrl == null) {			System.out.println("\nClass '" + className + 				"' not found.");		} else {			System.out.println("\nClass '" + className + 				"' found in \n'" + classUrl.getFile() + "'");		}		validate();		printClasspath();	}	/**	 * Returns the URL of the resource denoted by the specified	 * class name, as prescribed by the class path.	 *	 * @param className Name of the class.	 * @return Class URL, or null of the class was not found.	 */	public static URL findClass(final String className) {		return JWhich.class.getResource(asResourceName(className));	}	protected static String asResourceName(String resource) {		if (!resource.startsWith("/")) {			resource = "/" + resource;		}		resource = resource.replace('.', '/');		resource = resource + ".class";		return resource;	}	/**	 * Validates the class path and reports any non-existent	 * or invalid class path entries.	 * <p>	 * Valid class path entries include directories, <code>.zip</code> 	 * files, and <code>.jar</code> files.	 */	public static void validate() {				StringTokenizer tokenizer = 			new StringTokenizer(getClasspath(), File.pathSeparator);				while (tokenizer.hasMoreTokens()) {			String element = tokenizer.nextToken();			File f = new File(element);			if (!f.exists()) {				System.out.println("\nClasspath element '" + 					element + "' " + "does not exist.");			} else if ( (!f.isDirectory()) && 					  (!element.toLowerCase().endsWith(".jar")) &&					  (!element.toLowerCase().endsWith(".zip")) ) {				System.out.println("\nClasspath element '" + 					element + "' " +					"is not a directory, .jar file, or .zip file.");			}		}	}	public static void printClasspath() {		System.out.println("\nClasspath:");		StringTokenizer tokenizer = 			new StringTokenizer(getClasspath(), File.pathSeparator);		while (tokenizer.hasMoreTokens()) {			System.out.println(tokenizer.nextToken());		}		}	public static void setClasspath(String classpath) {		CLASSPATH = classpath;	}	protected static String getClasspath() {		if (CLASSPATH == null) {			setClasspath(System.getProperty("java.class.path"));		}		return CLASSPATH;	}	private static void instanceMain(String[] args) {		if (args.length == 0) {			printUsage();		}		for (int cmdIndex = 0; cmdIndex < args.length; cmdIndex++) {			String cmd = args[cmdIndex];			if ("-help".equals(cmd)) {				printUsage();			} else {				which(cmd);			}		}	}			private static void printUsage() {		System.out.println("\nSyntax: java JWhich [options] className");		System.out.println("");		System.out.println("where options include:");		System.out.println("");		System.out.println("\t-help     Prints usage information.");			System.out.println("");				System.out.println("Examples:");			System.out.println("\tjava JWhich MyClass");		System.out.println("\tjava JWhich my.package.MyClass");		System.exit(0);	}	public static void main(String args[]) {		JWhich.instanceMain(args);	}}