1 /* 2 * reserved comment block 3 * DO NOT REMOVE OR ALTER! 4 */ 5 /* 6 * Licensed to the Apache Software Foundation (ASF) under one or more 7 * contributor license agreements. See the NOTICE file distributed with 8 * this work for additional information regarding copyright ownership. 9 * The ASF licenses this file to You under the Apache License, Version 2.0 10 * (the "License"); you may not use this file except in compliance with 11 * the License. You may obtain a copy of the License at 12 * 13 * http://www.apache.org/licenses/LICENSE-2.0 14 * 15 * Unless required by applicable law or agreed to in writing, software 16 * distributed under the License is distributed on an "AS IS" BASIS, 17 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 18 * See the License for the specific language governing permissions and 19 * limitations under the License. 20 */ 21 22 package com.sun.org.apache.bcel.internal.classfile; 23 24 import java.io.DataInput; 25 import java.io.DataOutputStream; 26 import java.io.IOException; 27 28 import com.sun.org.apache.bcel.internal.Const; 29 30 /** 31 * This class is derived from <em>Attribute</em> and represents a constant 32 * value, i.e., a default value for initializing a class field. 33 * This class is instantiated by the <em>Attribute.readAttribute()</em> method. 34 * 35 * @see Attribute 36 */ 37 public final class ConstantValue extends Attribute { 38 39 private int constantvalue_index; 40 41 42 /** 43 * Initialize from another object. Note that both objects use the same 44 * references (shallow copy). Use clone() for a physical copy. 45 */ ConstantValue(final ConstantValue c)46 public ConstantValue(final ConstantValue c) { 47 this(c.getNameIndex(), c.getLength(), c.getConstantValueIndex(), c.getConstantPool()); 48 } 49 50 51 /** 52 * Construct object from input stream. 53 * @param name_index Name index in constant pool 54 * @param length Content length in bytes 55 * @param input Input stream 56 * @param constant_pool Array of constants 57 * @throws IOException 58 */ ConstantValue(final int name_index, final int length, final DataInput input, final ConstantPool constant_pool)59 ConstantValue(final int name_index, final int length, final DataInput input, final ConstantPool constant_pool) 60 throws IOException { 61 this(name_index, length, input.readUnsignedShort(), constant_pool); 62 } 63 64 65 /** 66 * @param name_index Name index in constant pool 67 * @param length Content length in bytes 68 * @param constantvalue_index Index in constant pool 69 * @param constant_pool Array of constants 70 */ ConstantValue(final int name_index, final int length, final int constantvalue_index, final ConstantPool constant_pool)71 public ConstantValue(final int name_index, final int length, final int constantvalue_index, 72 final ConstantPool constant_pool) { 73 super(Const.ATTR_CONSTANT_VALUE, name_index, length, constant_pool); 74 this.constantvalue_index = constantvalue_index; 75 } 76 77 78 /** 79 * Called by objects that are traversing the nodes of the tree implicitely 80 * defined by the contents of a Java class. I.e., the hierarchy of methods, 81 * fields, attributes, etc. spawns a tree of objects. 82 * 83 * @param v Visitor object 84 */ 85 @Override accept( final Visitor v )86 public void accept( final Visitor v ) { 87 v.visitConstantValue(this); 88 } 89 90 91 /** 92 * Dump constant value attribute to file stream on binary format. 93 * 94 * @param file Output file stream 95 * @throws IOException 96 */ 97 @Override dump( final DataOutputStream file )98 public void dump( final DataOutputStream file ) throws IOException { 99 super.dump(file); 100 file.writeShort(constantvalue_index); 101 } 102 103 104 /** 105 * @return Index in constant pool of constant value. 106 */ getConstantValueIndex()107 public int getConstantValueIndex() { 108 return constantvalue_index; 109 } 110 111 112 /** 113 * @param constantvalue_index the index info the constant pool of this constant value 114 */ setConstantValueIndex( final int constantvalue_index )115 public void setConstantValueIndex( final int constantvalue_index ) { 116 this.constantvalue_index = constantvalue_index; 117 } 118 119 120 /** 121 * @return String representation of constant value. 122 */ 123 @Override toString()124 public String toString() { 125 Constant c = super.getConstantPool().getConstant(constantvalue_index); 126 String buf; 127 int i; 128 // Print constant to string depending on its type 129 switch (c.getTag()) { 130 case Const.CONSTANT_Long: 131 buf = String.valueOf(((ConstantLong) c).getBytes()); 132 break; 133 case Const.CONSTANT_Float: 134 buf = String.valueOf(((ConstantFloat) c).getBytes()); 135 break; 136 case Const.CONSTANT_Double: 137 buf = String.valueOf(((ConstantDouble) c).getBytes()); 138 break; 139 case Const.CONSTANT_Integer: 140 buf = String.valueOf(((ConstantInteger) c).getBytes()); 141 break; 142 case Const.CONSTANT_String: 143 i = ((ConstantString) c).getStringIndex(); 144 c = super.getConstantPool().getConstant(i, Const.CONSTANT_Utf8); 145 buf = "\"" + Utility.convertString(((ConstantUtf8) c).getBytes()) + "\""; 146 break; 147 default: 148 throw new IllegalStateException("Type of ConstValue invalid: " + c); 149 } 150 return buf; 151 } 152 153 154 /** 155 * @return deep copy of this attribute 156 */ 157 @Override copy( final ConstantPool _constant_pool )158 public Attribute copy( final ConstantPool _constant_pool ) { 159 final ConstantValue c = (ConstantValue) clone(); 160 c.setConstantPool(_constant_pool); 161 return c; 162 } 163 } 164