WhereIsThisComingFrom.java

package cloader;

import java.net.URL;
import java.util.Enumeration;

public class WhereIsThisComingFrom
{
    public static void main(String[] args)
    {
        ClassLoader cl = Thread.currentThread().getContextClassLoader();

        locate(cl, "org/apache/juli/logging/Log.class");
        locate(cl, "org/eclipse/jetty/apache/jsp/JuliLog.class");
    }

    public static void locate(ClassLoader cl, Class<?> clazz)
    {
        String classAsResource = clazz.getName().replace('.', '/') + ".class";
        locate(cl, classAsResource);
    }

    public static void locate(ClassLoader cl, String resourceName)
    {
        try
        {
            Enumeration<URL> urls = cl.getResources(resourceName);
            System.out.printf("Looking for: %s%n", resourceName);
            while (urls.hasMoreElements())
            {
                URL url = urls.nextElement();
                System.out.printf(" - Found: %s%n", url.toExternalForm());
            }
        }
        catch (Throwable t)
        {
            System.out.printf("Whoops: cannot locate: %s%n", resourceName);
            t.printStackTrace();
        }
    }
}