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