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;
021import java.util.Objects;
022
023import org.apache.commons.compress.utils.CharsetNames;
024
025/**
026 * UTF8 constant pool entry, used for storing long Strings.
027 */
028public class CPUTF8 extends ConstantPoolEntry {
029
030    private final String utf8;
031
032    private boolean hashCodeComputed;
033
034    private int cachedHashCode;
035
036    public CPUTF8(final String string) {
037        this(string, -1);
038    }
039
040    /**
041     * Creates a new CPUTF8 instance
042     *
043     * @param utf8        TODO
044     * @param globalIndex - index in CpBands
045     * @throws NullPointerException if utf8 is null
046     */
047    public CPUTF8(final String utf8, final int globalIndex) {
048        super(ConstantPoolEntry.CP_UTF8, globalIndex);
049        this.utf8 = Objects.requireNonNull(utf8, "utf8");
050    }
051
052    @Override
053    public boolean equals(final Object obj) {
054        if (this == obj) {
055            return true;
056        }
057        if (obj == null) {
058            return false;
059        }
060        if (this.getClass() != obj.getClass()) {
061            return false;
062        }
063        final CPUTF8 other = (CPUTF8) obj;
064        return utf8.equals(other.utf8);
065    }
066
067    private void generateHashCode() {
068        hashCodeComputed = true;
069        final int PRIME = 31;
070        cachedHashCode = PRIME + utf8.hashCode();
071    }
072
073    @Override
074    public int hashCode() {
075        if (!hashCodeComputed) {
076            generateHashCode();
077        }
078        return cachedHashCode;
079    }
080
081    public void setGlobalIndex(final int index) {
082        globalIndex = index;
083    }
084
085    @Override
086    public String toString() {
087        return CharsetNames.UTF_8 + ":" + utf8;
088    }
089
090    public String underlyingString() {
091        return utf8;
092    }
093
094    @Override
095    protected void writeBody(final DataOutputStream dos) throws IOException {
096        dos.writeUTF(utf8);
097    }
098}