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 * 017 */ 018package org.apache.bcel.classfile; 019 020import java.io.DataInput; 021import java.io.DataOutputStream; 022import java.io.IOException; 023 024import org.apache.bcel.Const; 025 026/** 027 * This class is derived from the abstract {@link Constant} and represents a reference to the name and signature of a 028 * field or method. 029 * 030 * @see Constant 031 */ 032public final class ConstantNameAndType extends Constant { 033 034 private int nameIndex; // Name of field/method 035 private int signatureIndex; // and its signature. 036 037 /** 038 * Initialize from another object. 039 */ 040 public ConstantNameAndType(final ConstantNameAndType c) { 041 this(c.getNameIndex(), c.getSignatureIndex()); 042 } 043 044 /** 045 * Initialize instance from file data. 046 * 047 * @param file Input stream 048 * @throws IOException if an I/O error occurs. 049 */ 050 ConstantNameAndType(final DataInput file) throws IOException { 051 this(file.readUnsignedShort(), file.readUnsignedShort()); 052 } 053 054 /** 055 * @param nameIndex Name of field/method 056 * @param signatureIndex and its signature 057 */ 058 public ConstantNameAndType(final int nameIndex, final int signatureIndex) { 059 super(Const.CONSTANT_NameAndType); 060 this.nameIndex = nameIndex; 061 this.signatureIndex = signatureIndex; 062 } 063 064 /** 065 * Called by objects that are traversing the nodes of the tree implicitly defined by the contents of a Java class. 066 * I.e., the hierarchy of methods, fields, attributes, etc. spawns a tree of objects. 067 * 068 * @param v Visitor object 069 */ 070 @Override 071 public void accept(final Visitor v) { 072 v.visitConstantNameAndType(this); 073 } 074 075 /** 076 * Dump name and signature index to file stream in binary format. 077 * 078 * @param file Output file stream 079 * @throws IOException if an I/O error occurs. 080 */ 081 @Override 082 public void dump(final DataOutputStream file) throws IOException { 083 file.writeByte(super.getTag()); 084 file.writeShort(nameIndex); 085 file.writeShort(signatureIndex); 086 } 087 088 /** 089 * @return name 090 */ 091 public String getName(final ConstantPool cp) { 092 return cp.constantToString(getNameIndex(), Const.CONSTANT_Utf8); 093 } 094 095 /** 096 * @return Name index in constant pool of field/method name. 097 */ 098 public int getNameIndex() { 099 return nameIndex; 100 } 101 102 /** 103 * @return signature 104 */ 105 public String getSignature(final ConstantPool cp) { 106 return cp.constantToString(getSignatureIndex(), Const.CONSTANT_Utf8); 107 } 108 109 /** 110 * @return Index in constant pool of field/method signature. 111 */ 112 public int getSignatureIndex() { 113 return signatureIndex; 114 } 115 116 /** 117 * @param nameIndex the name index of this constant 118 */ 119 public void setNameIndex(final int nameIndex) { 120 this.nameIndex = nameIndex; 121 } 122 123 /** 124 * @param signatureIndex the signature index in the constant pool of this type 125 */ 126 public void setSignatureIndex(final int signatureIndex) { 127 this.signatureIndex = signatureIndex; 128 } 129 130 /** 131 * @return String representation 132 */ 133 @Override 134 public String toString() { 135 return super.toString() + "(nameIndex = " + nameIndex + ", signatureIndex = " + signatureIndex + ")"; 136 } 137}