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 * @version $Id: ClassLoaderRepository.java 1749603 2016-06-21 20:50:19Z ggregory $
038 */
039public class ClassLoaderRepository implements Repository {
040
041    private final java.lang.ClassLoader loader;
042    private final Map<String, JavaClass> loadedClasses = new HashMap<>(); // CLASSNAME X JAVACLASS
043
044
045    public ClassLoaderRepository(final java.lang.ClassLoader loader) {
046        this.loader = loader;
047    }
048
049
050    /**
051     * Store a new JavaClass into this Repository.
052     */
053    @Override
054    public void storeClass( final JavaClass clazz ) {
055        loadedClasses.put(clazz.getClassName(), clazz);
056        clazz.setRepository(this);
057    }
058
059
060    /**
061     * Remove class from repository
062     */
063    @Override
064    public void removeClass( final JavaClass clazz ) {
065        loadedClasses.remove(clazz.getClassName());
066    }
067
068
069    /**
070     * Find an already defined JavaClass.
071     */
072    @Override
073    public JavaClass findClass( final String className ) {
074        return loadedClasses.containsKey(className) ? loadedClasses.get(className) : null;
075    }
076
077
078    /**
079     * Lookup a JavaClass object from the Class Name provided.
080     */
081    @Override
082    public JavaClass loadClass(final String className) throws ClassNotFoundException {
083        final String classFile = className.replace('.', '/');
084        JavaClass RC = findClass(className);
085        if (RC != null) {
086            return RC;
087        }
088        try (InputStream is = loader.getResourceAsStream(classFile + ".class")) {
089            if (is == null) {
090                throw new ClassNotFoundException(className + " not found.");
091            }
092            final ClassParser parser = new ClassParser(is, className);
093            RC = parser.parse();
094            storeClass(RC);
095            return RC;
096        } catch (final IOException e) {
097            throw new ClassNotFoundException(className + " not found: " + e, e);
098        }
099    }
100
101
102    @Override
103    public JavaClass loadClass( final Class<?> clazz ) throws ClassNotFoundException {
104        return loadClass(clazz.getName());
105    }
106
107
108    /** Clear all entries from cache.
109     */
110    @Override
111    public void clear() {
112        loadedClasses.clear();
113    }
114
115
116    /*
117     * @return null
118     */
119    @Override
120    public ClassPath getClassPath() {
121        return null;
122    }
123}