Which.java

/*
 * Copyright (c) 1997, 2021 Oracle and/or its affiliates. All rights reserved.
 *
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Distribution License v. 1.0, which is available at
 * http://www.eclipse.org/org/documents/edl-v10.php.
 *
 * SPDX-License-Identifier: BSD-3-Clause
 */

package org.glassfish.jaxb.core.util;

import java.net.URL;

/**
 * Finds out where a class file is loaded from.
 * 
 * @author
 *     Kohsuke Kawaguchi (kohsuke.kawaguchi@sun.com)
 */
public class Which {

    private Which() {}

    public static String which( Class<?> clazz ) {
        return which( clazz.getName(), SecureLoader.getClassClassLoader(clazz));
    }

    /**
     * Search the specified classloader for the given classname.
     * Then give the return value.
     * @param classname the fully qualified name of the class to search for
     * @param loader the classloader to search
     * @return the source location of the resource, or null if it wasn't found
     */
    public static String which(String classname, ClassLoader loader) {

        String classnameAsResource = classname.replace('.', '/') + ".class";

        if(loader == null) {
            loader = SecureLoader.getSystemClassLoader();
        }
        
        URL it = loader.getResource(classnameAsResource);
        if (it != null) {
            return it.toString();
        } else {
            return null;
        }
    }

}