Mega Code Archive
Jar Class Loader
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/*
* Copyright 2002 Sun Microsystems, 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:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* - Redistribution 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.
*
* Neither the name of Sun Microsystems, Inc. or the names of
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* This software is provided "AS IS," without a warranty of any
* kind. ALL EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND
* WARRANTIES, INCLUDING ANY IMPLIED WARRANTY OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT, ARE HEREBY
* EXCLUDED. SUN AND ITS LICENSORS SHALL NOT BE LIABLE FOR ANY
* DAMAGES OR LIABILITIES SUFFERED BY LICENSEE AS A RESULT OF OR
* RELATING TO USE, MODIFICATION OR DISTRIBUTION OF THIS SOFTWARE OR
* ITS DERIVATIVES. IN NO EVENT WILL SUN OR ITS LICENSORS BE LIABLE
* FOR ANY LOST REVENUE, PROFIT OR DATA, OR FOR DIRECT, INDIRECT,
* SPECIAL, CONSEQUENTIAL, INCIDENTAL OR PUNITIVE DAMAGES, HOWEVER
* CAUSED AND REGARDLESS OF THE THEORY OF LIABILITY, ARISING OUT OF
* THE USE OF OR INABILITY TO USE THIS SOFTWARE, EVEN IF SUN HAS
* BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.
*
* You acknowledge that this software is not designed, licensed or
* intended for use in the design, construction, operation or
* maintenance of any nuclear facility.
*/
import java.io.IOException;
import java.net.URL;
import java.net.URLClassLoader;
import java.util.jar.Attributes;
import java.util.logging.Level;
import java.util.logging.Logger;
/**
* A class loader for loading jar files, both local and remote.
* Adapted from the Java Tutorial.
*
* http://java.sun.com/docs/books/tutorial/jar/api/index.html
*
* @version 1.3 02/27/02
* @author Mark Davidson
*/
public class JarClassLoader extends URLClassLoader {
// These manifest attributes were left out of Attributes.Name
// They have to go somewhere so the chaces are if you need them,
// then you are playing with this class loader.
public static final Attributes.Name Attributes_Name_JAVA_BEAN = new Attributes.Name("Java-Bean");
public static final Attributes.Name Attributes_Name_NAME = new Attributes.Name("Name");
private static JarClassLoader loader = null;
/**
* Null ctor DO NOT USE. This will result in an NPE if the class loader is
* used. So this class loader isn't really Bean like.
*/
public JarClassLoader() {
this(null);
}
/**
* Creates a new JarClassLoader for the specified url.
*
* @param url The url of the jar file i.e. http://www.xxx.yyy/jarfile.jar
* or file:c:\foo\lib\testbeans.jar
*/
public JarClassLoader(URL url) {
super(new URL[] { url });
}
/**
* Adds the jar file with the following url into the class loader. This can be
* a local or network resource.
*
* @param url The url of the jar file i.e. http://www.xxx.yyy/jarfile.jar
* or file:c:\foo\lib\testbeans.jar
*/
public void addJarFile(URL url) {
addURL(url);
}
/**
* Adds a jar file from the filesystems into the jar loader list.
*
* @param jarfile The full path to the jar file.
*/
public void addJarFile(String jarfile) {
try {
URL url = new URL("file:" + jarfile);
addURL(url);
} catch (IOException ex) {
Logger.getAnonymousLogger().log(Level.WARNING, "Error adding jar file", ex);
}
}
//
// Static methods for handling the shared instance of the JarClassLoader.
//
/**
* Returns the shared instance of the class loader.
*/
public static JarClassLoader getJarClassLoader() {
return loader;
}
/**
* Sets the static instance of the class loader.
*/
public static void setJarClassLoader(JarClassLoader cl) {
loader = cl;
}
}
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