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 * An {@link Attribute} representing a constant. 024 */ 025public class ConstantValueAttribute extends Attribute { 026 027 private int constantIndex; 028 029 private final ClassFileEntry entry; 030 031 private static CPUTF8 attributeName; 032 033 public static void setAttributeName(final CPUTF8 cpUTF8Value) { 034 attributeName = cpUTF8Value; 035 } 036 037 public ConstantValueAttribute(final ClassFileEntry entry) { 038 super(attributeName); 039 if (entry == null) { 040 throw new NullPointerException(); 041 } 042 this.entry = entry; 043 } 044 045 @Override 046 public boolean equals(final Object obj) { 047 if (this == obj) { 048 return true; 049 } 050 if (!super.equals(obj)) { 051 return false; 052 } 053 if (this.getClass() != obj.getClass()) { 054 return false; 055 } 056 final ConstantValueAttribute other = (ConstantValueAttribute) obj; 057 if (entry == null) { 058 if (other.entry != null) { 059 return false; 060 } 061 } else if (!entry.equals(other.entry)) { 062 return false; 063 } 064 return true; 065 } 066 067 @Override 068 protected int getLength() { 069 return 2; 070 } 071 072 @Override 073 protected ClassFileEntry[] getNestedClassFileEntries() { 074 return new ClassFileEntry[] {getAttributeName(), entry}; 075 } 076 077 @Override 078 public int hashCode() { 079 final int PRIME = 31; 080 int result = super.hashCode(); 081 result = PRIME * result + ((entry == null) ? 0 : entry.hashCode()); 082 return result; 083 } 084 085 @Override 086 protected void resolve(final ClassConstantPool pool) { 087 super.resolve(pool); 088 entry.resolve(pool); 089 this.constantIndex = pool.indexOf(entry); 090 } 091 092 @Override 093 public String toString() { 094 return "Constant:" + entry; 095 } 096 097 @Override 098 protected void writeBody(final DataOutputStream dos) throws IOException { 099 dos.writeShort(constantIndex); 100 } 101 102}