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Java > Open Source Codes > jbet > CpFieldRef


1 /*
2  * JBET - Java Binary Enhancement Tool
3  * Copyright (c) 2003 Networks Associates Technology, Inc.
4  *
5  * This software was developed under DARPA/SPAWAR contract
6  * N66001-00-C-8602 "SPMA" as part of the
7  * DARPA OASIS research program.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  * notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  * notice, this list of conditions and the following disclaimer in the
16  * documentation and/or other materials provided with the distribution.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
19  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21  * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
22  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28  * SUCH DAMAGE.
29  */
30
31 /**
32  * Represent a reference to a field in the constant pool. Each
33  * instruction that references a field (variable) indexes one of
34  * these.
35  *
36  * $Id: CpFieldRef.java,v 1.4 2003/09/09 17:31:53 areisse Exp $
37  *
38  * @author Larry D'Anna
39  * @author Lee Badger
40  * @version 0.1
41  * @since JDK 1.1.8
42  */
43 package jbet;
44 import java.io.*;
45
46 class CpFieldRef extends CpEntry {
47     int classIndex = -1; // JVM spec 4.4.2 class_index
48 int nameAndTypeIndex = -1; // " name_and_type_index
49
50     String JavaDoc cname, // Class name
51 fname; // field name
52 Type t; // field type
53
54
55     // Constructors
56
57     /**
58      * Used by ConstantPool.ConstantPool(DataInputStream dataIn)...
59      * during Pass 1.
60      *
61      * @param i index into the our representation of the constant pool
62      */
63     CpFieldRef(int i, CPInterface cp) {
64     super(i, CPInterface.CONSTANT_Fieldref, cp);
65     }
66
67
68     /**
69      * Used by ConstantPool.internFieldRef(String cname, String mname,
70      * Type type)
71      * wich in involked by Instruction.resolveConstants().
72      *
73      * @see CPInterface.internFieldRef
74      * @see Instruction.resolveConstants
75      *
76      */
77     CpFieldRef(CPInterface cp, String JavaDoc cname, String JavaDoc fname, Type t) {
78     super(cp.poolCount(), CPInterface.CONSTANT_Fieldref, cp);
79     this.cname = cname;
80     this.fname = fname;
81     this.t = t;
82     }
83     
84     public String JavaDoc toString() {
85     return classname() + " " + name() + " " + type();
86     }
87
88     String JavaDoc classname() { return cname; }
89     String JavaDoc name() { return fname; }
90     Type type() { return t; }
91
92     /**
93      * Resolve index fields into direct references to objects. Called
94      * in pass-3 of the ConstantPool's initialization.
95      */
96     void setup() throws ClassFileException {
97     if (cname == null || fname == null || t == null) {
98         CpClass cpc = constantPool.cpClassAt(classIndex);
99         cpc.setup();
100         CpNameAndType cpnat = constantPool.cpNameAndTypeAt(nameAndTypeIndex);
101         cpnat.setup();
102         cname = cpc.string();
103         fname = cpnat.name();
104         t = cpnat.type();
105     }
106     }
107
108     public int hashCode() {
109     return cname.hashCode() + fname.hashCode() + t.hashCode();
110     }
111
112     public boolean equals(Object JavaDoc o) {
113     if (!( o instanceof CpFieldRef)) return false;
114     CpFieldRef cp = (CpFieldRef) o;
115     return cp.cname.equals(cname) && cp.fname.equals(fname) &&
116         cp.t.equals(t);
117     }
118
119
120     void write(DataOutputStream dataOut) throws IOException {
121     dataOut.writeByte(tag);
122     dataOut.writeShort(classIndex);
123     dataOut.writeShort(nameAndTypeIndex);
124     }
125
126 }
127
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