/*
* Javassist, a Java-bytecode translator toolkit.
* Copyright (C) 1999- Shigeru Chiba. All Rights Reserved.
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (the "License"); you may not use this file except in compliance with
* the License. Alternatively, the contents of this file may be used under
* the terms of the GNU Lesser General Public License Version 2.1 or later,
* or the Apache License Version 2.0.
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*/
package javassist;
import java.io.
InputStream;
import java.lang.ref.
Reference;
import java.lang.ref.
WeakReference;
import java.net.
URL;
/**
* A class search-path representing a class loader.
*
* <p>It is used for obtaining a class file from the given
* class loader by <code>getResourceAsStream()</code>.
* The <code>LoaderClassPath</code> refers to the class loader through
* <code>WeakReference</code>. If the class loader is garbage collected,
* the other search pathes are examined.
*
* <p>The given class loader must have both <code>getResourceAsStream()</code>
* and <code>getResource()</code>.
*
* <p>Class files in a named module are private to that module.
* This method cannot obtain class files in named modules.
* </p>
*
* @author <a href="mailto:bill@jboss.org">Bill Burke</a>
* @author Shigeru Chiba
*
* @see ClassPool#insertClassPath(ClassPath)
* @see ClassPool#appendClassPath(ClassPath)
* @see ClassClassPath
*/
public class
LoaderClassPath implements
ClassPath {
private
Reference<
ClassLoader>
clref;
/**
* Creates a search path representing a class loader.
*/
public
LoaderClassPath(
ClassLoader cl) {
clref = new
WeakReference<
ClassLoader>(
cl);
}
@
Override
public
String toString() {
return
clref.
get() == null ? "<null>" :
clref.
get().
toString();
}
/**
* Obtains a class file from the class loader.
* This method calls <code>getResourceAsStream(String)</code>
* on the class loader.
*/
@
Override
public
InputStream openClassfile(
String classname) throws
NotFoundException {
String cname =
classname.
replace('.', '/') + ".class";
ClassLoader cl =
clref.
get();
if (
cl == null)
return null; // not found
InputStream is =
cl.
getResourceAsStream(
cname);
return
is;
}
/**
* Obtains the URL of the specified class file.
* This method calls <code>getResource(String)</code>
* on the class loader.
*
* @return null if the class file could not be found.
*/
@
Override
public
URL find(
String classname) {
String cname =
classname.
replace('.', '/') + ".class";
ClassLoader cl =
clref.
get();
if (
cl == null)
return null; // not found
URL url =
cl.
getResource(
cname);
return
url;
}
}