juzu.impl.common.ParentJarClassLoader Maven / Gradle / Ivy
/*
* Copyright 2013 eXo Platform SAS
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package juzu.impl.common;
import java.io.IOException;
import java.net.URL;
import java.util.Enumeration;
import java.util.NoSuchElementException;
/**
* A classloader implementation that blacklists any class or resources not loaded from a jar file of the parent loader.
Julien Viet
*/
public class ParentJarClassLoader extends ClassLoader {
/** . */
private final ClassLoader parent;
public ParentJarClassLoader(ClassLoader parent) {
super(parent);
//
this.parent = parent;
}
@Override
protected Class loadClass(String name, boolean resolve) throws ClassNotFoundException {
Class found = super.loadClass(name, resolve);
if (found.getClassLoader() == super.getParent()) {
URL url = super.getResource(name.replace('.', '/') + ".class");
if (shouldLoad(url)) {
return found;
} else {
throw new ClassNotFoundException();
}
}
return found;
}
static final java.lang.reflect.Method findResource;
static final java.lang.reflect.Method findResources;
static {
try {
findResource = ClassLoader.class.getDeclaredMethod("findResource", String.class);
findResource.setAccessible(true);
findResources = ClassLoader.class.getDeclaredMethod("findResources", String.class);
findResources.setAccessible(true);
}
catch (NoSuchMethodException e) {
throw new UnsupportedOperationException("Impossible to get findResource from ClassLoader class", e);
}
}
@Override
public URL getResource(String name) {
URL url;
try {
url = (URL)findResource.invoke(parent, name);
}
catch (Exception e) {
throw new UnsupportedOperationException("Not yet handled", e);
}
if (url != null) {
if (shouldLoad(url)) {
return url;
} else {
return null;
}
} else {
return super.getResource(name);
}
}
@Override
public Enumeration getResources(final String name) throws IOException {
Enumeration parentResources;
try {
parentResources = (Enumeration)findResources.invoke(parent, name);
}
catch (Exception e) {
throw new UnsupportedOperationException("Not yet handled", e);
}
Enumeration ancestorResources = parent.getParent().getResources(name);
final Enumeration[] resources = new Enumeration[]{parentResources, ancestorResources};
return new Enumeration() {
URL next = null;
int index = 0;
public boolean hasMoreElements() {
while (next == null) {
if (index < resources.length) {
if (resources[index].hasMoreElements()) {
URL url = resources[index].nextElement();
if (index > 0 || shouldLoad(url)) {
next = url;
}
} else {
index++;
}
} else {
break;
}
}
return next != null;
}
public URL nextElement() {
if (!hasMoreElements()) {
throw new NoSuchElementException("No more elements");
}
try {
return next;
}
finally {
next = null;
}
}
};
}
private boolean shouldLoad(URL url) {
String s = url.toString();
return s.contains(".jar!/") || s.contains(".zip!/");
}
}