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.commons.compress.harmony.unpack200.bytecode;
018
019import java.io.DataOutputStream;
020import java.io.IOException;
021
022/**
023 * UTF8 constant pool entry, used for storing long Strings.
024 */
025public class CPUTF8 extends ConstantPoolEntry {
026
027    private final String utf8;
028
029    /**
030     * Creates a new CPUTF8 instance
031     *
032     * @param utf8 TODO
033     * @param globalIndex - index in CpBands
034     * @throws NullPointerException if utf8 is null
035     */
036    public CPUTF8(final String utf8, final int globalIndex) {
037        super(ConstantPoolEntry.CP_UTF8, globalIndex);
038        this.utf8 = utf8;
039        if (utf8 == null) {
040            throw new NullPointerException("Null arguments are not allowed");
041        }
042    }
043
044    public CPUTF8(final String string) {
045        this(string, -1);
046    }
047
048    @Override
049    public boolean equals(final Object obj) {
050        if (this == obj) {
051            return true;
052        }
053        if (obj == null) {
054            return false;
055        }
056        if (this.getClass() != obj.getClass()) {
057            return false;
058        }
059        final CPUTF8 other = (CPUTF8) obj;
060        return utf8.equals(other.utf8);
061    }
062
063    private boolean hashcodeComputed;
064    private int cachedHashCode;
065
066    private void generateHashCode() {
067        hashcodeComputed = true;
068        final int PRIME = 31;
069        cachedHashCode = PRIME + utf8.hashCode();
070    }
071
072    @Override
073    public int hashCode() {
074        if (!hashcodeComputed) {
075            generateHashCode();
076        }
077        return cachedHashCode;
078    }
079
080    @Override
081    public String toString() {
082        return "UTF8: " + utf8;
083    }
084
085    @Override
086    protected void writeBody(final DataOutputStream dos) throws IOException {
087        dos.writeUTF(utf8);
088    }
089
090    public String underlyingString() {
091        return utf8;
092    }
093
094    public void setGlobalIndex(final int index) {
095        globalIndex = index;
096    }
097}