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 * String constant pool entry.
024 */
025public class CPString extends CPConstant {
026
027    private transient int nameIndex;
028    private final CPUTF8 name;
029
030    public CPString(final CPUTF8 value, final int globalIndex) {
031        super(ConstantPoolEntry.CP_String, value, globalIndex);
032        this.name = value;
033    }
034
035    @Override
036    protected void writeBody(final DataOutputStream dos) throws IOException {
037        dos.writeShort(nameIndex);
038    }
039
040    @Override
041    public String toString() {
042        return "String: " + getValue();
043    }
044
045    /**
046     * Allows the constant pool entries to resolve their nested entries
047     *
048     * @param pool TODO
049     */
050    @Override
051    protected void resolve(final ClassConstantPool pool) {
052        super.resolve(pool);
053        nameIndex = pool.indexOf(name);
054    }
055
056    @Override
057    protected ClassFileEntry[] getNestedClassFileEntries() {
058        return new ClassFileEntry[] {name};
059    }
060
061    private boolean hashcodeComputed;
062    private int cachedHashCode;
063
064    private void generateHashCode() {
065        hashcodeComputed = true;
066        final int PRIME = 31;
067        int result = 1;
068        result = PRIME * result + name.hashCode();
069        cachedHashCode = result;
070    }
071
072    @Override
073    public int hashCode() {
074        if (!hashcodeComputed) {
075            generateHashCode();
076        }
077        return cachedHashCode;
078    }
079}