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Java > Open Source Codes > org > apache > tools > ant > taskdefs > optional > sitraka > bytecode > MethodInfo


1 /*
2  * Copyright 2001-2002,2004 The Apache Software Foundation
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  * http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  *
16  */
17 package org.apache.tools.ant.taskdefs.optional.sitraka.bytecode;
18
19 import java.io.DataInputStream JavaDoc;
20 import java.io.IOException JavaDoc;
21 import org.apache.tools.ant.taskdefs.optional.depend.constantpool.ConstantPool;
22 import org.apache.tools.ant.taskdefs.optional.sitraka.bytecode.attributes.AttributeInfo;
23
24 /**
25  * Method info structure.
26  * @todo give a more appropriate name to methods.
27  *
28  */
29 public final class MethodInfo {
30     private int access_flags;
31     private int loc = -1;
32     private String JavaDoc name;
33     private String JavaDoc descriptor;
34
35     public MethodInfo() {
36     }
37
38     public void read(ConstantPool constantPool, DataInputStream JavaDoc dis) throws IOException JavaDoc {
39         access_flags = dis.readShort();
40
41         int name_index = dis.readShort();
42         name = Utils.getUTF8Value(constantPool, name_index);
43
44         int descriptor_index = dis.readShort();
45         descriptor = Utils.getUTF8Value(constantPool, descriptor_index);
46
47         int attributes_count = dis.readUnsignedShort();
48         for (int i = 0; i < attributes_count; i++) {
49             int attr_id = dis.readShort();
50             String JavaDoc attr_name = Utils.getUTF8Value(constantPool, attr_id);
51             int len = dis.readInt();
52             if (AttributeInfo.CODE.equals(attr_name)) {
53                 readCode(constantPool, dis);
54             } else {
55                 dis.skipBytes(len);
56             }
57         }
58
59     }
60
61     protected void readCode(ConstantPool constantPool, DataInputStream JavaDoc dis) throws IOException JavaDoc {
62         // skip max_stack (short), max_local (short)
63 dis.skipBytes(2 * 2);
64
65         // skip bytecode...
66 int bytecode_len = dis.readInt();
67         dis.skip(bytecode_len);
68
69         // skip exceptions... 1 exception = 4 short.
70 int exception_count = dis.readShort();
71         dis.skipBytes(exception_count * 4 * 2);
72
73         // read attributes...
74 int attributes_count = dis.readUnsignedShort();
75         for (int i = 0; i < attributes_count; i++) {
76             int attr_id = dis.readShort();
77             String JavaDoc attr_name = Utils.getUTF8Value(constantPool, attr_id);
78             int len = dis.readInt();
79             if (AttributeInfo.LINE_NUMBER_TABLE.equals(attr_name)) {
80                 // we're only interested in lines of code...
81 loc = dis.readShort();
82                 // skip the table which is 2*loc*short
83 dis.skip(loc * 2 * 2);
84             } else {
85                 dis.skipBytes(len);
86             }
87         }
88     }
89
90     public int getAccessFlags() {
91         return access_flags;
92     }
93
94     public String JavaDoc getName() {
95         return name;
96     }
97
98     public String JavaDoc getDescriptor() {
99         return descriptor;
100     }
101
102     public String JavaDoc getFullSignature() {
103         return getReturnType() + " " + getShortSignature();
104     }
105
106     public String JavaDoc getShortSignature() {
107         StringBuffer JavaDoc buf = new StringBuffer JavaDoc(getName());
108         buf.append("(");
109         String JavaDoc[] params = getParametersType();
110         for (int i = 0; i < params.length; i++) {
111             buf.append(params[i]);
112             if (i != params.length - 1) {
113                 buf.append(", ");
114             }
115         }
116         buf.append(")");
117         return buf.toString();
118     }
119
120     public String JavaDoc getReturnType() {
121         return Utils.getMethodReturnType(getDescriptor());
122     }
123
124     public String JavaDoc[] getParametersType() {
125         return Utils.getMethodParams(getDescriptor());
126     }
127
128     public int getNumberOfLines() {
129         return loc;
130     }
131
132     public String JavaDoc getAccess() {
133         return Utils.getMethodAccess(access_flags);
134     }
135
136     public String JavaDoc toString() {
137         StringBuffer JavaDoc sb = new StringBuffer JavaDoc();
138         sb.append("Method: ").append(getAccess()).append(" ");
139         sb.append(getFullSignature());
140         return sb.toString();
141     }
142 }
143
144
145
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