    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;
    021import java.util.Objects;
    022
    023/**
    024 * Field reference constant pool entry.
    025 */
    026public class CPFieldRef extends ConstantPoolEntry {
    027
    028    CPClass className;
    029    transient int classNameIndex;
    030    private final CPNameAndType nameAndType;
    031    transient int nameAndTypeIndex;
    032
    033    private boolean hashCodeComputed;
    034
    035    private int cachedHashCode;
    036
    037    public CPFieldRef(final CPClass className, final CPNameAndType descriptor, final int globalIndex) {
    038        super(ConstantPoolEntry.CP_Fieldref, globalIndex);
    039        this.className = className;
    040        this.nameAndType = descriptor;
    041    }
    042
    043    @Override
    044    public boolean equals(final Object obj) {
    045        if (this == obj) {
    046            return true;
    047        }
    048        if (obj == null) {
    049            return false;
    050        }
    051        if (getClass() != obj.getClass()) {
    052            return false;
    053        }
    054        final CPFieldRef other = (CPFieldRef) obj;
    055        if (!Objects.equals(className, other.className)) {
    056            return false;
    057        }
    058        if (!Objects.equals(nameAndType, other.nameAndType)) {
    059            return false;
    060        }
    061        return true;
    062    }
    063
    064    private void generateHashCode() {
    065        hashCodeComputed = true;
    066        final int PRIME = 31;
    067        int result = 1;
    068        result = PRIME * result + ((className == null) ? 0 : className.hashCode());
    069        result = PRIME * result + ((nameAndType == null) ? 0 : nameAndType.hashCode());
    070        cachedHashCode = result;
    071    }
    072
    073    @Override
    074    protected ClassFileEntry[] getNestedClassFileEntries() {
    075        return new ClassFileEntry[] {className, nameAndType};
    076    }
    077    @Override
    078    public int hashCode() {
    079        if (!hashCodeComputed) {
    080            generateHashCode();
    081        }
    082        return cachedHashCode;
    083    }
    084
    085    @Override
    086    protected void resolve(final ClassConstantPool pool) {
    087        super.resolve(pool);
    088        nameAndTypeIndex = pool.indexOf(nameAndType);
    089        classNameIndex = pool.indexOf(className);
    090    }
    091
    092    @Override
    093    public String toString() {
    094        return "FieldRef: " + className + "#" + nameAndType;
    095    }
    096
    097    @Override
    098    protected void writeBody(final DataOutputStream dos) throws IOException {
    099        dos.writeShort(classNameIndex);
    100        dos.writeShort(nameAndTypeIndex);
    101    }
    102
    103}