1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one
3 * or more contributor license agreements. See the NOTICE file
4 * distributed with this work for additional information
5 * regarding copyright ownership. The ASF licenses this file
6 * to you under the Apache License, Version 2.0 (the
7 * "License"); you may not use this file except in compliance
8 * with the License. You may obtain a copy of the License at
9 *
10 * https://www.apache.org/licenses/LICENSE-2.0
11 *
12 * Unless required by applicable law or agreed to in writing,
13 * software distributed under the License is distributed on an
14 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
15 * KIND, either express or implied. See the License for the
16 * specific language governing permissions and limitations
17 * under the License.
18 */
19 package org.apache.bcel.classfile;
20
21 import java.io.DataInput;
22 import java.io.DataOutputStream;
23 import java.io.IOException;
24
25 import org.apache.bcel.Const;
26
27 /**
28 * This class is derived from the abstract {@link Constant} and represents a reference to the name and signature of a
29 * field or method.
30 *
31 * @see Constant
32 */
33 public final class ConstantNameAndType extends Constant {
34
35 private int nameIndex; // Name of field/method
36 private int signatureIndex; // and its signature.
37
38 /**
39 * Initialize from another object.
40 *
41 * @param c Source to copy.
42 */
43 public ConstantNameAndType(final ConstantNameAndType c) {
44 this(c.getNameIndex(), c.getSignatureIndex());
45 }
46
47 /**
48 * Initialize instance from file data.
49 *
50 * @param file Input stream.
51 * @throws IOException if an I/O error occurs.
52 */
53 ConstantNameAndType(final DataInput file) throws IOException {
54 this(file.readUnsignedShort(), file.readUnsignedShort());
55 }
56
57 /**
58 * Constructs a ConstantNameAndType.
59 *
60 * @param nameIndex Name of field/method.
61 * @param signatureIndex and its signature.
62 */
63 public ConstantNameAndType(final int nameIndex, final int signatureIndex) {
64 super(Const.CONSTANT_NameAndType);
65 this.nameIndex = nameIndex;
66 this.signatureIndex = signatureIndex;
67 }
68
69 /**
70 * Called by objects that are traversing the nodes of the tree implicitly defined by the contents of a Java class.
71 * I.e., the hierarchy of methods, fields, attributes, etc. spawns a tree of objects.
72 *
73 * @param v Visitor object.
74 */
75 @Override
76 public void accept(final Visitor v) {
77 v.visitConstantNameAndType(this);
78 }
79
80 /**
81 * Dumps name and signature index to file stream in binary format.
82 *
83 * @param file Output file stream.
84 * @throws IOException if an I/O error occurs.
85 */
86 @Override
87 public void dump(final DataOutputStream file) throws IOException {
88 file.writeByte(super.getTag());
89 file.writeShort(nameIndex);
90 file.writeShort(signatureIndex);
91 }
92
93 /**
94 * Gets the name.
95 *
96 * @param cp the constant pool.
97 * @return name.
98 */
99 public String getName(final ConstantPool cp) {
100 return cp.constantToString(getNameIndex(), Const.CONSTANT_Utf8);
101 }
102
103 /**
104 * Gets the name index in constant pool of field/method name.
105 *
106 * @return Name index in constant pool of field/method name.
107 */
108 public int getNameIndex() {
109 return nameIndex;
110 }
111
112 /**
113 * Gets the signature.
114 *
115 * @param cp the constant pool.
116 * @return signature.
117 */
118 public String getSignature(final ConstantPool cp) {
119 return cp.constantToString(getSignatureIndex(), Const.CONSTANT_Utf8);
120 }
121
122 /**
123 * Gets the index in constant pool of field/method signature.
124 *
125 * @return Index in constant pool of field/method signature.
126 */
127 public int getSignatureIndex() {
128 return signatureIndex;
129 }
130
131 /**
132 * Sets the name index.
133 *
134 * @param nameIndex the name index of this constant.
135 */
136 public void setNameIndex(final int nameIndex) {
137 this.nameIndex = nameIndex;
138 }
139
140 /**
141 * Sets the signature index.
142 *
143 * @param signatureIndex the signature index in the constant pool of this type.
144 */
145 public void setSignatureIndex(final int signatureIndex) {
146 this.signatureIndex = signatureIndex;
147 }
148
149 /**
150 * @return String representation.
151 */
152 @Override
153 public String toString() {
154 return super.toString() + "(nameIndex = " + nameIndex + ", signatureIndex = " + signatureIndex + ")";
155 }
156 }