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