001: /* ====================================================================
002: * The QueryForm License, Version 1.1
003: *
004: * Copyright (c) 1998 - 2003 David F. Glasser. All rights
005: * reserved.
006: *
007: * Redistribution and use in source and binary forms, with or without
008: * modification, are permitted provided that the following conditions
009: * are met:
010: *
011: * 1. Redistributions of source code must retain the above copyright
012: * notice, this list of conditions and the following disclaimer.
013: *
014: * 2. Redistributions in binary form must reproduce the above copyright
015: * notice, this list of conditions and the following disclaimer in
016: * the documentation and/or other materials provided with the
017: * distribution.
018: *
019: * 3. The end-user documentation included with the redistribution,
020: * if any, must include the following acknowledgment:
021: * "This product includes software developed by
022: * David F. Glasser."
023: * Alternately, this acknowledgment may appear in the software itself,
024: * if and wherever such third-party acknowledgments normally appear.
025: *
026: * 4. The names "QueryForm" and "David F. Glasser" must
027: * not be used to endorse or promote products derived from this
028: * software without prior written permission. For written
029: * permission, please contact dglasser@pobox.com.
030: *
031: * 5. Products derived from this software may not be called "QueryForm",
032: * nor may "QueryForm" appear in their name, without prior written
033: * permission of David F. Glasser.
034: *
035: * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
036: * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
037: * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
038: * DISCLAIMED. IN NO EVENT SHALL DAVID F. GLASSER, THE APACHE SOFTWARE
039: * FOUNDATION OR ITS CONTRIBUTORS, OR ANY AUTHORS OR DISTRIBUTORS
040: * OF THIS SOFTWARE BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
041: * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
042: * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
043: * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
044: * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
045: * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
046: * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
047: * SUCH DAMAGE.
048: * ====================================================================
049: *
050: * This product includes software developed by the
051: * Apache Software Foundation (http://www.apache.org/).
052: *
053: * ====================================================================
054: *
055: * $Source: /cvsroot/qform/qform/src/org/glasser/util/ExtensionClassLoader.java,v $
056: * $Revision: 1.2 $
057: * $Author: dglasser $
058: * $Date: 2003/02/02 14:35:11 $
059: *
060: * --------------------------------------------------------------------
061: */
062: package org.glasser.util;
063:
064: import java.net.*;
065: import java.io.*;
066:
067: /**
068: * This is a URLClassLoader with some minor functionality added. It has
069: * a Singleton instance which is globally accessible, and it also
070: * has a method (addArchivesInDirectory(File directory) that adds all
071: * of the jar and zip files in a given directory to the classpath for
072: * an instance of this classloader.
073: */
074: public class ExtensionClassLoader extends java.net.URLClassLoader {
075:
076: public static boolean debug = System
077: .getProperty("ExtensionClassLoader.debug") != null;
078:
079: /**
080: * This is not a Singleton class in the strict sense that only one instance
081: * can be created, (the constructors are public) however there is one instance
082: * that is globally accessible.
083: */
084: private final static ExtensionClassLoader singleton = new ExtensionClassLoader(
085: new URL[0]);
086:
087: static class ArchiveFilter implements java.io.FileFilter {
088:
089: public boolean accept(File pathName) {
090: String upcase = pathName.getName().toUpperCase();
091: if (upcase.endsWith(".ZIP") || upcase.endsWith(".JAR"))
092: return true;
093: return false;
094: }
095: }
096:
097: private ArchiveFilter archiveFilter = new ArchiveFilter();
098:
099: public ExtensionClassLoader(URL[] urls) {
100: super (urls);
101: }
102:
103: public ExtensionClassLoader(URL[] urls, ClassLoader parent) {
104: super (urls, parent);
105: }
106:
107: public ExtensionClassLoader(URL[] urls, ClassLoader parent,
108: URLStreamHandlerFactory factory) {
109: super (urls, parent, factory);
110: }
111:
112: /**
113: * This is not a Singleton instance in the strict sense that only one instance
114: * can be created, (the constructors are public) however there is one instance
115: * that is globally accessible.
116: */
117: public static ExtensionClassLoader getSingleton() {
118: return singleton;
119: }
120:
121: public void addArchivesInDirectory(File directory)
122: throws MalformedURLException {
123: if (directory.isDirectory() == false) {
124: throw new IllegalArgumentException(
125: "directory argument is not a directory.");
126: }
127: if (debug)
128: System.out.println("Adding archives in " + directory
129: + " to ExtensionClassLoader classpath.");
130:
131: File[] archives = directory.listFiles(archiveFilter);
132: for (int j = 0; archives != null && j < archives.length; j++) {
133: if (debug)
134: System.out.println("Adding " + archives[j]
135: + " to ExtensionClassLoader classpath.");
136: this.addURL(archives[j].toURL());
137: }
138: }
139:
140: }
|