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