1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one or more
3 * contributor license agreements. See the NOTICE file distributed with
4 * this work for additional information regarding copyright ownership.
5 * The ASF licenses this file to You under the Apache License, Version 2.0
6 * (the "License"); you may not use this file except in compliance with
7 * the License. You may obtain a copy of the License at
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 */
17 package org.apache.bcel.classfile;
18
19 import java.io.DataInput;
20 import java.io.DataOutputStream;
21 import java.io.IOException;
22
23 import org.apache.bcel.Const;
24
25 /**
26 * This class is derived from the abstract {@link Constant} and represents a reference to the name and signature of a
27 * field or method.
28 *
29 * @see Constant
30 */
31 public final class ConstantNameAndType extends Constant {
32
33 private int nameIndex; // Name of field/method
34 private int signatureIndex; // and its signature.
35
36 /**
37 * Initialize from another object.
38 *
39 * @param c Source to copy.
40 */
41 public ConstantNameAndType(final ConstantNameAndType c) {
42 this(c.getNameIndex(), c.getSignatureIndex());
43 }
44
45 /**
46 * Initialize instance from file data.
47 *
48 * @param file Input stream
49 * @throws IOException if an I/O error occurs.
50 */
51 ConstantNameAndType(final DataInput file) throws IOException {
52 this(file.readUnsignedShort(), file.readUnsignedShort());
53 }
54
55 /**
56 * @param nameIndex Name of field/method
57 * @param signatureIndex and its signature
58 */
59 public ConstantNameAndType(final int nameIndex, final int signatureIndex) {
60 super(Const.CONSTANT_NameAndType);
61 this.nameIndex = nameIndex;
62 this.signatureIndex = signatureIndex;
63 }
64
65 /**
66 * Called by objects that are traversing the nodes of the tree implicitly defined by the contents of a Java class.
67 * I.e., the hierarchy of methods, fields, attributes, etc. spawns a tree of objects.
68 *
69 * @param v Visitor object
70 */
71 @Override
72 public void accept(final Visitor v) {
73 v.visitConstantNameAndType(this);
74 }
75
76 /**
77 * Dump name and signature index to file stream in binary format.
78 *
79 * @param file Output file stream
80 * @throws IOException if an I/O error occurs.
81 */
82 @Override
83 public void dump(final DataOutputStream file) throws IOException {
84 file.writeByte(super.getTag());
85 file.writeShort(nameIndex);
86 file.writeShort(signatureIndex);
87 }
88
89 /**
90 * @return name
91 */
92 public String getName(final ConstantPool cp) {
93 return cp.constantToString(getNameIndex(), Const.CONSTANT_Utf8);
94 }
95
96 /**
97 * @return Name index in constant pool of field/method name.
98 */
99 public int getNameIndex() {
100 return nameIndex;
101 }
102
103 /**
104 * @return signature
105 */
106 public String getSignature(final ConstantPool cp) {
107 return cp.constantToString(getSignatureIndex(), Const.CONSTANT_Utf8);
108 }
109
110 /**
111 * @return Index in constant pool of field/method signature.
112 */
113 public int getSignatureIndex() {
114 return signatureIndex;
115 }
116
117 /**
118 * @param nameIndex the name index of this constant
119 */
120 public void setNameIndex(final int nameIndex) {
121 this.nameIndex = nameIndex;
122 }
123
124 /**
125 * @param signatureIndex the signature index in the constant pool of this type
126 */
127 public void setSignatureIndex(final int signatureIndex) {
128 this.signatureIndex = signatureIndex;
129 }
130
131 /**
132 * @return String representation
133 */
134 @Override
135 public String toString() {
136 return super.toString() + "(nameIndex = " + nameIndex + ", signatureIndex = " + signatureIndex + ")";
137 }
138 }