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