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 * Abstract superclass for reference constant pool entries, such as a method or field reference.
025 */
026public abstract class CPRef extends ConstantPoolEntry {
027
028    CPClass className;
029    transient int classNameIndex;
030
031    protected CPNameAndType nameAndType;
032    transient int nameAndTypeIndex;
033
034    /**
035     * Create a new CPRef
036     *
037     * @param type TODO
038     * @param className TODO
039     * @param descriptor TODO
040     * @param globalIndex index in CpBands
041     * @throws NullPointerException if descriptor or className is null
042     */
043    public CPRef(final byte type, final CPClass className, final CPNameAndType descriptor, final int globalIndex) {
044        super(type, globalIndex);
045        this.className = Objects.requireNonNull(className, "className");
046        this.nameAndType = Objects.requireNonNull(descriptor, "descriptor");
047    }
048
049    @Override
050    public boolean equals(final Object obj) {
051        if (this == obj) {
052            return true;
053        }
054        if (obj == null) {
055            return false;
056        }
057        if (getClass() != obj.getClass()) {
058            return false;
059        }
060        if (this.hashCode() != obj.hashCode()) {
061            return false;
062        }
063        final CPRef other = (CPRef) obj;
064        if (!className.equals(other.className)) {
065            return false;
066        }
067        if (!nameAndType.equals(other.nameAndType)) {
068            return false;
069        }
070        return true;
071    }
072
073    @Override
074    protected ClassFileEntry[] getNestedClassFileEntries() {
075        final ClassFileEntry[] entries = new ClassFileEntry[2];
076        entries[0] = className;
077        entries[1] = nameAndType;
078        return entries;
079    }
080
081    @Override
082    protected void resolve(final ClassConstantPool pool) {
083        super.resolve(pool);
084        nameAndTypeIndex = pool.indexOf(nameAndType);
085        classNameIndex = pool.indexOf(className);
086    }
087
088    protected String cachedToString;
089
090    @Override
091    public String toString() {
092        if (cachedToString == null) {
093            String type;
094            if (getTag() == ConstantPoolEntry.CP_Fieldref) {
095                type = "FieldRef"; //$NON-NLS-1$
096            } else if (getTag() == ConstantPoolEntry.CP_Methodref) {
097                type = "MethoddRef"; //$NON-NLS-1$
098            } else if (getTag() == ConstantPoolEntry.CP_InterfaceMethodref) {
099                type = "InterfaceMethodRef"; //$NON-NLS-1$
100            } else {
101                type = "unknown"; //$NON-NLS-1$
102            }
103            cachedToString = type + ": " + className + "#" + nameAndType; //$NON-NLS-1$ //$NON-NLS-2$
104        }
105        return cachedToString;
106    }
107
108    @Override
109    protected void writeBody(final DataOutputStream dos) throws IOException {
110        dos.writeShort(classNameIndex);
111        dos.writeShort(nameAndTypeIndex);
112    }
113
114}