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
019/**
020 * Abstract superclass for constant pool constant entries such as numbers or Strings
021 */
022public abstract class CPConstant extends ConstantPoolEntry {
023
024    private final Object value;
025
026    /**
027     * Create a new CPConstant
028     *
029     * @param tag TODO
030     * @param value TODO
031     * @param globalIndex index in CpBands
032     * @throws NullPointerException if value is null
033     */
034    public CPConstant(final byte tag, final Object value, final int globalIndex) {
035        super(tag, globalIndex);
036        this.value = value;
037        if (value == null) {
038            throw new NullPointerException("Null arguments are not allowed");
039        }
040    }
041
042    @Override
043    public boolean equals(final Object obj) {
044        if (this == obj) {
045            return true;
046        }
047        if (obj == null) {
048            return false;
049        }
050        if (this.getClass() != obj.getClass()) {
051            return false;
052        }
053        final CPConstant other = (CPConstant) obj;
054        if (value == null) {
055            if (other.value != null) {
056                return false;
057            }
058        } else if (!value.equals(other.value)) {
059            return false;
060        }
061        return true;
062    }
063
064    @Override
065    public int hashCode() {
066        final int PRIME = 31;
067        int result = 1;
068        result = PRIME * result + ((value == null) ? 0 : value.hashCode());
069        return result;
070    }
071
072    protected Object getValue() {
073        return value;
074    }
075}