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 * Abstract superclass for reference constant pool entries, such as a method or field reference.
024 */
025public abstract class CPRef extends ConstantPoolEntry {
026
027    CPClass className;
028    transient int classNameIndex;
029
030    protected CPNameAndType nameAndType;
031    transient int nameAndTypeIndex;
032
033    /**
034     * Create a new CPRef
035     *
036     * @param type TODO
037     * @param className TODO
038     * @param descriptor TODO
039     * @param globalIndex index in CpBands
040     * @throws NullPointerException if descriptor or className is null
041     */
042    public CPRef(final byte type, final CPClass className, final CPNameAndType descriptor, final int globalIndex) {
043        super(type, globalIndex);
044        this.className = className;
045        this.nameAndType = descriptor;
046        if (descriptor == null || className == null) {
047            throw new NullPointerException("Null arguments are not allowed");
048        }
049    }
050
051    @Override
052    public boolean equals(final Object obj) {
053        if (this == obj) {
054            return true;
055        }
056        if (obj == null) {
057            return false;
058        }
059        if (getClass() != obj.getClass()) {
060            return false;
061        }
062        if (this.hashCode() != obj.hashCode()) {
063            return false;
064        }
065        final CPRef other = (CPRef) obj;
066        if (!className.equals(other.className)) {
067            return false;
068        }
069        if (!nameAndType.equals(other.nameAndType)) {
070            return false;
071        }
072        return true;
073    }
074
075    @Override
076    protected ClassFileEntry[] getNestedClassFileEntries() {
077        final ClassFileEntry[] entries = new ClassFileEntry[2];
078        entries[0] = className;
079        entries[1] = nameAndType;
080        return entries;
081    }
082
083    @Override
084    protected void resolve(final ClassConstantPool pool) {
085        super.resolve(pool);
086        nameAndTypeIndex = pool.indexOf(nameAndType);
087        classNameIndex = pool.indexOf(className);
088    }
089
090    protected String cachedToString;
091
092    @Override
093    public String toString() {
094        if (cachedToString == null) {
095            String type;
096            if (getTag() == ConstantPoolEntry.CP_Fieldref) {
097                type = "FieldRef"; //$NON-NLS-1$
098            } else if (getTag() == ConstantPoolEntry.CP_Methodref) {
099                type = "MethoddRef"; //$NON-NLS-1$
100            } else if (getTag() == ConstantPoolEntry.CP_InterfaceMethodref) {
101                type = "InterfaceMethodRef"; //$NON-NLS-1$
102            } else {
103                type = "unknown"; //$NON-NLS-1$
104            }
105            cachedToString = type + ": " + className + "#" + nameAndType; //$NON-NLS-1$ //$NON-NLS-2$
106        }
107        return cachedToString;
108    }
109
110    @Override
111    protected void writeBody(final DataOutputStream dos) throws IOException {
112        dos.writeShort(classNameIndex);
113        dos.writeShort(nameAndTypeIndex);
114    }
115
116}