001/*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements.  See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License.  You may obtain a copy of the License at
008 *
009 *      http://www.apache.org/licenses/LICENSE-2.0
010 *
011 *  Unless required by applicable law or agreed to in writing, software
012 *  distributed under the License is distributed on an "AS IS" BASIS,
013 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 *  See the License for the specific language governing permissions and
015 *  limitations under the License.
016 *
017 */
018package org.apache.bcel.util;
019
020import java.io.IOException;
021import java.io.InputStream;
022import java.util.HashMap;
023import java.util.Map;
024
025import org.apache.bcel.classfile.ClassParser;
026import org.apache.bcel.classfile.JavaClass;
027
028/**
029 * The repository maintains information about which classes have
030 * been loaded.
031 *
032 * It loads its data from the ClassLoader implementation
033 * passed into its constructor.
034 *
035 * @see org.apache.bcel.Repository
036 *
037 */
038public class ClassLoaderRepository implements Repository {
039
040    private final java.lang.ClassLoader loader;
041    private final Map<String, JavaClass> loadedClasses = new HashMap<>(); // CLASSNAME X JAVACLASS
042
043
044    public ClassLoaderRepository(final java.lang.ClassLoader loader) {
045        this.loader = loader;
046    }
047
048
049    /**
050     * Store a new JavaClass into this Repository.
051     */
052    @Override
053    public void storeClass( final JavaClass clazz ) {
054        loadedClasses.put(clazz.getClassName(), clazz);
055        clazz.setRepository(this);
056    }
057
058
059    /**
060     * Remove class from repository
061     */
062    @Override
063    public void removeClass( final JavaClass clazz ) {
064        loadedClasses.remove(clazz.getClassName());
065    }
066
067
068    /**
069     * Find an already defined JavaClass.
070     */
071    @Override
072    public JavaClass findClass( final String className ) {
073        return loadedClasses.containsKey(className) ? loadedClasses.get(className) : null;
074    }
075
076
077    /**
078     * Lookup a JavaClass object from the Class Name provided.
079     */
080    @Override
081    public JavaClass loadClass(final String className) throws ClassNotFoundException {
082        final String classFile = className.replace('.', '/');
083        JavaClass RC = findClass(className);
084        if (RC != null) {
085            return RC;
086        }
087        try (InputStream is = loader.getResourceAsStream(classFile + ".class")) {
088            if (is == null) {
089                throw new ClassNotFoundException(className + " not found.");
090            }
091            final ClassParser parser = new ClassParser(is, className);
092            RC = parser.parse();
093            storeClass(RC);
094            return RC;
095        } catch (final IOException e) {
096            throw new ClassNotFoundException(className + " not found: " + e, e);
097        }
098    }
099
100
101    @Override
102    public JavaClass loadClass( final Class<?> clazz ) throws ClassNotFoundException {
103        return loadClass(clazz.getName());
104    }
105
106
107    /** Clear all entries from cache.
108     */
109    @Override
110    public void clear() {
111        loadedClasses.clear();
112    }
113
114
115    /*
116     * @return null
117     */
118    @Override
119    public ClassPath getClassPath() {
120        return null;
121    }
122}