/*
 * @(#)DefaultLoaderRepository.java	1.18 04/05/18
 * 
 * Copyright 2004 Sun Microsystems, Inc. All rights reserved.
 * SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 */

package javax.management.loading;


// Java import

import java.security.AccessController;
import java.security.Permission;
import java.util.Iterator;
import java.util.List;

// JMX import
import javax.management.MBeanServer;
import javax.management.MBeanServerFactory;
import javax.management.loading.ClassLoaderRepository;

import com.sun.jmx.trace.Trace;

/**
 * <p>Keeps the list of Class Loaders registered in the MBean Server.
 * It provides the necessary methods to load classes using the registered 
 * Class Loaders.</p>
 *
 * <p>This deprecated class is maintained for compatibility.  In
 * previous versions of JMX, there was one
 * <code>DefaultLoaderRepository</code> shared by all MBean servers.
 * As of JMX 1.2, that functionality is approximated by using {@link
 * MBeanServerFactory#findMBeanServer} to find all known MBean
 * servers, and consulting the {@link ClassLoaderRepository} of each
 * one.  It is strongly recommended that code referencing
 * <code>DefaultLoaderRepository</code> be rewritten.</p>
 *
 * @deprecated Use 
 * {@link javax.management.MBeanServer#getClassLoaderRepository()}} 
 * instead.
 *
 * @since 1.5
 */
@Deprecated
public class DefaultLoaderRepository {

    private static final String dbgTag = "DefaultLoaderRepository";

    /**
     * Go through the list of class loaders and try to load the requested 
     * class.
     * The method will stop as soon as the class is found. If the class
     * is not found the method will throw a <CODE>ClassNotFoundException</CODE>
     * exception.
     *
     * @param className The name of the class to be loaded.
     *
     * @return the loaded class.
     *
     * @exception ClassNotFoundException The specified class could not be 
     *            found.
     */
    public static Class loadClass(String className)  
	throws ClassNotFoundException {
	debug("loadClass",className);
	return load(null, className);
    }

    /**
     * Go through the list of class loaders but exclude the given 
     * class loader, then try to load 
     * the requested class.
     * The method will stop as soon as the class is found. If the class
     * is not found the method will throw a <CODE>ClassNotFoundException</CODE>
     * exception.
     *
     * @param className The name of the class to be loaded.
     * @param loader The class loader to be excluded.
     *
     * @return the loaded class.
     *
     * @exception ClassNotFoundException The specified class could not be 
     *    found.
     */
    public static Class loadClassWithout(ClassLoader loader,
					 String className) 
	throws ClassNotFoundException {
	debug("loadClassWithout",className);
	return load(loader, className);
    }

    private static Class load(ClassLoader without, String className)
	    throws ClassNotFoundException {
	final List mbsList = MBeanServerFactory.findMBeanServer(null);

	for (Iterator it = mbsList.iterator(); it.hasNext(); ) {
	    MBeanServer mbs = (MBeanServer) it.next();
	    ClassLoaderRepository clr = mbs.getClassLoaderRepository();
	    try {
		return clr.loadClassWithout(without, className);
	    } catch (ClassNotFoundException e) {
		// OK : Try with next one...
	    }
	}
	throw new ClassNotFoundException(className);
    }
    
    // TRACES & DEBUG
    //---------------

    private static boolean isTraceOn() {
        return Trace.isSelected(Trace.LEVEL_TRACE, Trace.INFO_MBEANSERVER);
    }

    private static void trace(String clz, String func, String info) {
        Trace.send(Trace.LEVEL_TRACE, Trace.INFO_MBEANSERVER, clz, func, info);
    }

    private static void trace(String func, String info) {
        trace(dbgTag, func, info);
    }

    private static boolean isDebugOn() {
        return Trace.isSelected(Trace.LEVEL_DEBUG, Trace.INFO_MBEANSERVER);
    }

    private static void debug(String clz, String func, String info) {
        Trace.send(Trace.LEVEL_DEBUG, Trace.INFO_MBEANSERVER, clz, func, info);
    }

    private static void debug(String func, String info) {
        debug(dbgTag, func, info);
    }
 
 }
