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;
023
024/**
025 * String constant pool entry.
026 */
027public class CPString extends CPConstant {
028
029    private transient int nameIndex;
030    private final CPUTF8 name;
031
032    private boolean hashCodeComputed;
033
034    private int cachedHashCode;
035
036    /**
037     * Constructs a new instance.
038     *
039     * @param value The value.
040     * @param globalIndex Global index.
041     */
042    public CPString(final CPUTF8 value, final int globalIndex) {
043        super(CP_String, value, globalIndex);
044        this.name = value;
045    }
046
047    private void generateHashCode() {
048        hashCodeComputed = true;
049        final int PRIME = 31;
050        int result = 1;
051        result = PRIME * result + name.hashCode();
052        cachedHashCode = result;
053    }
054
055    @Override
056    protected ClassFileEntry[] getNestedClassFileEntries() {
057        return new ClassFileEntry[] { name };
058    }
059
060    @Override
061    public int hashCode() {
062        if (!hashCodeComputed) {
063            generateHashCode();
064        }
065        return cachedHashCode;
066    }
067
068    /**
069     * Allows the constant pool entries to resolve their nested entries
070     *
071     * @param pool TODO
072     */
073    @Override
074    protected void resolve(final ClassConstantPool pool) {
075        super.resolve(pool);
076        nameIndex = pool.indexOf(name);
077    }
078
079    @Override
080    public String toString() {
081        return "String: " + getValue();
082    }
083
084    @Override
085    protected void writeBody(final DataOutputStream dos) throws IOException {
086        dos.writeShort(nameIndex);
087    }
088}