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 */
017package org.apache.bcel.util;
018
019import java.io.IOException;
020import java.io.InputStream;
021import java.util.HashMap;
022import java.util.Map;
023
024import org.apache.bcel.classfile.ClassParser;
025import org.apache.bcel.classfile.JavaClass;
026import org.apache.bcel.classfile.Utility;
027
028/**
029 * The repository maintains information about which classes have been loaded.
030 *
031 * It loads its data from the ClassLoader implementation passed into its constructor.
032 *
033 * @see org.apache.bcel.Repository
034 */
035public class ClassLoaderRepository implements Repository {
036
037    private final java.lang.ClassLoader loader;
038    private final Map<String, JavaClass> loadedClasses = new HashMap<>(); // CLASSNAME X JAVACLASS
039
040    public ClassLoaderRepository(final java.lang.ClassLoader loader) {
041        this.loader = loader;
042    }
043
044    /**
045     * Clear all entries from cache.
046     */
047    @Override
048    public void clear() {
049        loadedClasses.clear();
050    }
051
052    /**
053     * Find an already defined JavaClass.
054     */
055    @Override
056    public JavaClass findClass(final String className) {
057        return loadedClasses.get(className);
058    }
059
060    /*
061     * @return null
062     */
063    @Override
064    public ClassPath getClassPath() {
065        return null;
066    }
067
068    @Override
069    public JavaClass loadClass(final Class<?> clazz) throws ClassNotFoundException {
070        return loadClass(clazz.getName());
071    }
072
073    /**
074     * Lookup a JavaClass object from the Class Name provided.
075     */
076    @Override
077    public JavaClass loadClass(final String className) throws ClassNotFoundException {
078        final String classFile = Utility.packageToPath(className);
079        JavaClass RC = findClass(className);
080        if (RC != null) {
081            return RC;
082        }
083        try (InputStream is = loader.getResourceAsStream(classFile + JavaClass.EXTENSION)) {
084            if (is == null) {
085                throw new ClassNotFoundException(className + " not found.");
086            }
087            final ClassParser parser = new ClassParser(is, className);
088            RC = parser.parse();
089            storeClass(RC);
090            return RC;
091        } catch (final IOException e) {
092            throw new ClassNotFoundException(className + " not found: " + e, e);
093        }
094    }
095
096    /**
097     * Remove class from repository
098     */
099    @Override
100    public void removeClass(final JavaClass clazz) {
101        loadedClasses.remove(clazz.getClassName());
102    }
103
104    /**
105     * Store a new JavaClass into this Repository.
106     */
107    @Override
108    public void storeClass(final JavaClass clazz) {
109        loadedClasses.put(clazz.getClassName(), clazz);
110        clazz.setRepository(this);
111    }
112}