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
18 package org.apache.bcel.classfile;
19
20 import java.io.DataInput;
21 import java.io.DataOutputStream;
22 import java.io.IOException;
23
24 import org.apache.bcel.Const;
25
26 /**
27 * Entry of the parameters table.
28 * <p>
29 * Implements {@link Node} as of 6.7.0.
30 * </p>
31 *
32 * @see <a href="https://docs.oracle.com/javase/specs/jvms/se8/html/jvms-4.html#jvms-4.7.24"> The class File Format :
33 * The MethodParameters Attribute</a>
34 * @since 6.0
35 */
36 public class MethodParameter implements Cloneable, Node {
37
38 /** Index of the CONSTANT_Utf8_info structure in the constant_pool table representing the name of the parameter */
39 private int nameIndex;
40
41 /** The access flags */
42 private int accessFlags;
43
44 public MethodParameter() {
45 }
46
47 /**
48 * Constructs an instance from a DataInput.
49 *
50 * @param input Input stream
51 * @throws IOException if an I/O error occurs.
52 * @throws ClassFormatException if a class is malformed or cannot be interpreted as a class file
53 */
54 MethodParameter(final DataInput input) throws IOException {
55 nameIndex = input.readUnsignedShort();
56 accessFlags = input.readUnsignedShort();
57 }
58
59 @Override
60 public void accept(final Visitor v) {
61 v.visitMethodParameter(this);
62 }
63
64 /**
65 * @return deep copy of this object
66 */
67 public MethodParameter copy() {
68 try {
69 return (MethodParameter) clone();
70 } catch (final CloneNotSupportedException e) {
71 // TODO should this throw?
72 }
73 return null;
74 }
75
76 /**
77 * Dumps object to file stream on binary format.
78 *
79 * @param file Output file stream
80 * @throws IOException if an I/O error occurs.
81 */
82 public final void dump(final DataOutputStream file) throws IOException {
83 file.writeShort(nameIndex);
84 file.writeShort(accessFlags);
85 }
86
87 public int getAccessFlags() {
88 return accessFlags;
89 }
90
91 public int getNameIndex() {
92 return nameIndex;
93 }
94
95 /**
96 * Gets the name of the parameter.
97 *
98 * @param constantPool The pool to query.
99 * @return Constant from the given pool.
100 */
101 public String getParameterName(final ConstantPool constantPool) {
102 if (nameIndex == 0) {
103 return null;
104 }
105 return constantPool.getConstantUtf8(nameIndex).getBytes();
106 }
107
108 public boolean isFinal() {
109 return (accessFlags & Const.ACC_FINAL) != 0;
110 }
111
112 public boolean isMandated() {
113 return (accessFlags & Const.ACC_MANDATED) != 0;
114 }
115
116 public boolean isSynthetic() {
117 return (accessFlags & Const.ACC_SYNTHETIC) != 0;
118 }
119
120 public void setAccessFlags(final int accessFlags) {
121 this.accessFlags = accessFlags;
122 }
123
124 public void setNameIndex(final int nameIndex) {
125 this.nameIndex = nameIndex;
126 }
127 }