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