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.util.HashMap;
022import java.util.Map;
023
024import org.apache.bcel.classfile.JavaClass;
025import org.apache.commons.lang3.ArrayUtils;
026
027/**
028 * Utility class implementing a (type-safe) set of JavaClass objects. Since JavaClass has no equals() method, the name of the class is used for comparison.
029 *
030 * @see ClassStack
031 */
032public class ClassSet {
033
034    private final Map<String, JavaClass> map = new HashMap<>();
035
036    /**
037     * Constructs a new ClassSet.
038     */
039    public ClassSet() {
040    }
041
042    /**
043     * Adds a JavaClass to the set.
044     *
045     * @param clazz the JavaClass to add.
046     * @return true if the class was added.
047     */
048    public boolean add(final JavaClass clazz) {
049        return map.putIfAbsent(clazz.getClassName(), clazz) != null;
050    }
051
052    /**
053     * Checks if the set is empty.
054     *
055     * @return true if the set is empty.
056     */
057    public boolean empty() {
058        return map.isEmpty();
059    }
060
061    /**
062     * Gets the class names in the set.
063     *
064     * @return the class names in the set.
065     */
066    public String[] getClassNames() {
067        return map.keySet().toArray(ArrayUtils.EMPTY_STRING_ARRAY);
068    }
069
070    /**
071     * Removes a JavaClass from the set.
072     *
073     * @param clazz the JavaClass to remove.
074     */
075    public void remove(final JavaClass clazz) {
076        map.remove(clazz.getClassName());
077    }
078
079    /**
080     * Converts the set to an array.
081     *
082     * @return an array of JavaClass objects.
083     */
084    public JavaClass[] toArray() {
085        return map.values().toArray(JavaClass.EMPTY_ARRAY);
086    }
087}