001    /*
002     * Copyright 2002-2004 The Apache Software Foundation
003     *
004     * Licensed under the Apache License, Version 2.0 (the "License");
005     * you may not use this file except in compliance with the License.
006     * You may obtain a copy of the License at
007     *
008     *     http://www.apache.org/licenses/LICENSE-2.0
009     *
010     * Unless required by applicable law or agreed to in writing, software
011     * distributed under the License is distributed on an "AS IS" BASIS,
012     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013     * See the License for the specific language governing permissions and
014     * limitations under the License.
015     */
016    package org.apache.commons.clazz;
017    
018    import java.util.HashMap;
019    
020    import org.apache.commons.clazz.common.GroupClazzLoader;
021    
022    /**
023     * An implementation of <code>ClazzLoader</code> that functions as the top-
024     * level clazz loader for a model and caches all clazzes by name.
025     *
026     * @author <a href="mailto:dmitri@apache.org">Dmitri Plotnikov</a>
027     * @version $Id: ModelClazzLoader.java 155436 2005-02-26 13:17:48Z dirkv $
028     */
029    public class ModelClazzLoader extends GroupClazzLoader {
030    
031        private String model;
032        private HashMap clazzMap = new HashMap();
033    
034        public ModelClazzLoader(String model) {
035            super(null);
036            this.model = model;
037        }
038        
039        public String getModel() {
040            return model;
041        }
042        
043        /**
044         * @see ClazzLoader#getClazzForName(String)
045         */
046        public Clazz getClazzForName(String name) {
047            Clazz clazz = (Clazz) clazzMap.get(name);
048            if (clazz == null) {
049                clazz = super.getClazzForName(name);
050                if (clazz != null) {
051                    clazzMap.put(name, clazz);
052                }
053            }
054            return clazz;
055        }
056    
057        /**
058         * @see ClazzLoader#defineClazz(String, Class, Class)
059         */
060        public Clazz defineClazz(
061                String name,
062                Class clazzType,
063                Class instanceClass) 
064        {
065            Clazz clazz = super.defineClazz(name, clazzType, instanceClass);
066            if (clazz != null) {
067                clazzMap.put(name, clazz);
068            }
069            return clazz;
070        }
071    }