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