001    /*
002     * $Id: ReflectorLoader.java 4542 2006-12-21 19:01:02Z blackdrag $
003     * 
004     * Copyright 2003 (C) Jochen Theodorou. All Rights Reserved.
005     * 
006     * Redistribution and use of this software and associated documentation
007     * ("Software"), with or without modification, are permitted provided that the
008     * following conditions are met: 1. Redistributions of source code must retain
009     * copyright statements and notices. Redistributions must also contain a copy
010     * of this document. 2. Redistributions in binary form must reproduce the above
011     * copyright notice, this list of conditions and the following disclaimer in
012     * the documentation and/or other materials provided with the distribution. 3.
013     * The name "groovy" must not be used to endorse or promote products derived
014     * from this Software without prior written permission of The Codehaus. For
015     * written permission, please contact info@codehaus.org. 4. Products derived
016     * from this Software may not be called "groovy" nor may "groovy" appear in
017     * their names without prior written permission of The Codehaus. "groovy" is a
018     * registered trademark of The Codehaus. 5. Due credit should be given to The
019     * Codehaus - http://groovy.codehaus.org/
020     * 
021     * THIS SOFTWARE IS PROVIDED BY THE CODEHAUS AND CONTRIBUTORS ``AS IS'' AND ANY
022     * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
023     * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
024     * DISCLAIMED. IN NO EVENT SHALL THE CODEHAUS OR ITS CONTRIBUTORS BE LIABLE FOR
025     * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
026     * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
027     * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
028     * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
029     * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
030     * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
031     * DAMAGE.
032     *  
033     */
034    package org.codehaus.groovy.runtime;
035    
036    import java.security.ProtectionDomain;
037    import java.util.HashMap;
038    
039    /**
040     * Reflector creation helper. This class is used to define the Refloctor classes.
041     * For each ClassLoader such a Loader will be created by the MetaClass.
042     * The only special about this loader is, that it knows the class Reflector, 
043     * which is the base class of all runtime created Reflectors. 
044     * 
045     * @author <a href="mailto:blackdrag@gmx.org">Jochen Theodorou</a>
046     * @version $Revision: 4542 $
047     */
048    public class ReflectorLoader extends ClassLoader {
049        private HashMap loadedClasses = new HashMap();
050        
051        /**
052         * returns the Reflector class.
053         * 
054         * @return the Reflector class if the name matches
055         * @throws ClassNotFoundException if the name is not matching Reflector
056         * @see Reflector
057         */
058        protected Class findClass(String name) throws ClassNotFoundException {
059            if (delegatationLoader==null) return super.loadClass(name);
060            return delegatationLoader.loadClass(name);
061        }
062        
063        /**
064         * helper method to define Reflector classes
065         * @param name of the Reflector
066         * @param bytecode the bytecode
067         * @param domain  the protection domain
068         * @return the generated class
069         */
070        public Class defineClass(String name, byte[] bytecode, ProtectionDomain domain) {
071            Class c = defineClass(name, bytecode, 0, bytecode.length, domain);
072            synchronized(loadedClasses) { loadedClasses.put(name,c); }
073            resolveClass(c);
074            return c;
075        }
076        
077        /**
078         * creates a RelfectorLoader. 
079         * @param parent the parent loader. This should never be null!
080         */
081        public ReflectorLoader(ClassLoader parent) {
082            super(parent);
083            delegatationLoader = getClass().getClassLoader();
084        }
085        
086        public Class getLoadedClass(String name) {
087            synchronized (loadedClasses) {
088                return (Class)loadedClasses.get(name);
089            }
090        }
091        
092        private ClassLoader delegatationLoader; 
093    }