    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.commons.compress.harmony.unpack200.bytecode;
    020
    021import java.io.DataOutputStream;
    022import java.io.IOException;
    023import java.nio.charset.StandardCharsets;
    024import java.util.Objects;
    025
    026/**
    027 * UTF8 constant pool entry, used for storing long Strings.
    028 */
    029public class CPUTF8 extends ConstantPoolEntry {
    030
    031    private final String utf8;
    032
    033    private boolean hashCodeComputed;
    034
    035    private int cachedHashCode;
    036
    037    /**
    038     * Constructs a new instance.
    039     *
    040     * @param string a constant pool string.
    041     */
    042    public CPUTF8(final String string) {
    043        this(string, -1);
    044    }
    045
    046    /**
    047     * Creates a new instance
    048     *
    049     * @param string      a constant pool string.
    050     * @param globalIndex index in CpBands
    051     * @throws NullPointerException if utf8 is null.
    052     */
    053    public CPUTF8(final String string, final int globalIndex) {
    054        super(CP_UTF8, globalIndex);
    055        this.utf8 = Objects.requireNonNull(string, "utf8");
    056    }
    057
    058    @Override
    059    public boolean equals(final Object obj) {
    060        if (this == obj) {
    061            return true;
    062        }
    063        if (obj == null || this.getClass() != obj.getClass()) {
    064            return false;
    065        }
    066        final CPUTF8 other = (CPUTF8) obj;
    067        return utf8.equals(other.utf8);
    068    }
    069
    070    private void generateHashCode() {
    071        hashCodeComputed = true;
    072        final int PRIME = 31;
    073        cachedHashCode = PRIME + utf8.hashCode();
    074    }
    075
    076    @Override
    077    public int hashCode() {
    078        if (!hashCodeComputed) {
    079            generateHashCode();
    080        }
    081        return cachedHashCode;
    082    }
    083
    084    /**
    085     * Sets the global index.
    086     *
    087     * @param index the global index.
    088     */
    089    public void setGlobalIndex(final int index) {
    090        globalIndex = index;
    091    }
    092
    093    @Override
    094    public String toString() {
    095        return StandardCharsets.UTF_8.name() + ":" + utf8;
    096    }
    097
    098    /**
    099     * Gets the underlying string.
    100     *
    101     * @return the underlying string.
    102     */
    103    public String underlyingString() {
    104        return utf8;
    105    }
    106
    107    @Override
    108    protected void writeBody(final DataOutputStream dos) throws IOException {
    109        dos.writeUTF(utf8);
    110    }
    111}