Mega Code Archive
Use reflection to access the true classpath info
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import java.lang.reflect.Method;
import java.net.URL;
import java.security.CodeSource;
import java.security.ProtectionDomain;
import java.util.HashSet;
import java.util.List;
import java.util.Set;
/*
* JBoss, Home of Professional Open Source
* Copyright 2005, JBoss Inc., and individual contributors as indicated
* by the @authors tag. See the copyright.txt in the distribution for a
* full listing of individual contributors.
*
* This is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation; either version 2.1 of
* the License, or (at your option) any later version.
*
* This software is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this software; if not, write to the Free
* Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA, or see the FSF site: http://www.fsf.org.
*/
public class Main {
/**
* Format a string buffer containing the Class, Interfaces, CodeSource, and
* ClassLoader information for the given object clazz.
*
* @param clazz
* the Class
* @param results -
* the buffer to write the info to
*/
public static void displayClassInfo(Class clazz, StringBuffer results) {
// Print out some codebase info for the clazz
ClassLoader cl = clazz.getClassLoader();
results.append("\n");
results.append(clazz.getName());
results.append("(");
results.append(Integer.toHexString(clazz.hashCode()));
results.append(").ClassLoader=");
results.append(cl);
ClassLoader parent = cl;
while (parent != null) {
results.append("\n..");
results.append(parent);
URL[] urls = getClassLoaderURLs(parent);
int length = urls != null ? urls.length : 0;
for (int u = 0; u < length; u++) {
results.append("\n....");
results.append(urls[u]);
}
if (parent != null)
parent = parent.getParent();
}
CodeSource clazzCS = clazz.getProtectionDomain().getCodeSource();
if (clazzCS != null) {
results.append("\n++++CodeSource: ");
results.append(clazzCS);
} else
results.append("\n++++Null CodeSource");
results.append("\nImplemented Interfaces:");
Class[] ifaces = clazz.getInterfaces();
for (int i = 0; i < ifaces.length; i++) {
Class iface = ifaces[i];
results.append("\n++");
results.append(iface);
results.append("(");
results.append(Integer.toHexString(iface.hashCode()));
results.append(")");
ClassLoader loader = ifaces[i].getClassLoader();
results.append("\n++++ClassLoader: ");
results.append(loader);
ProtectionDomain pd = ifaces[i].getProtectionDomain();
CodeSource cs = pd.getCodeSource();
if (cs != null) {
results.append("\n++++CodeSource: ");
results.append(cs);
} else
results.append("\n++++Null CodeSource");
}
}
/**
* Use reflection to access a URL[] getURLs or URL[] getClasspath method so
* that non-URLClassLoader class loaders, or class loaders that override
* getURLs to return null or empty, can provide the true classpath info.
*
* @param cl
* @return the urls
*/
public static URL[] getClassLoaderURLs(ClassLoader cl) {
URL[] urls = {};
try {
Class returnType = urls.getClass();
Class[] parameterTypes = {};
Class clClass = cl.getClass();
Method getURLs = clClass.getMethod("getURLs", parameterTypes);
if (returnType.isAssignableFrom(getURLs.getReturnType())) {
Object[] args = {};
urls = (URL[]) getURLs.invoke(cl, args);
}
if (urls == null || urls.length == 0) {
Method getCp = clClass.getMethod("getClasspath", parameterTypes);
if (returnType.isAssignableFrom(getCp.getReturnType())) {
Object[] args = {};
urls = (URL[]) getCp.invoke(cl, args);
}
}
} catch (Exception ignore) {
}
return urls;
}
}
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