    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}