1 /*
2 * reserved comment block
3 * DO NOT REMOVE OR ALTER!
4 */
5 package com.sun.org.apache.bcel.internal.classfile;
6
7 /* ====================================================================
8 * The Apache Software License, Version 1.1
9 *
10 * Copyright (c) 2001 The Apache Software Foundation. All rights
11 * reserved.
12 *
13 * Redistribution and use in source and binary forms, with or without
14 * modification, are permitted provided that the following conditions
15 * are met:
16 *
17 * 1. Redistributions of source code must retain the above copyright
18 * notice, this list of conditions and the following disclaimer.
19 *
20 * 2. Redistributions in binary form must reproduce the above copyright
21 * notice, this list of conditions and the following disclaimer in
22 * the documentation and/or other materials provided with the
23 * distribution.
24 *
25 * 3. The end-user documentation included with the redistribution,
26 * if any, must include the following acknowledgment:
27 * "This product includes software developed by the
28 * Apache Software Foundation (http://www.apache.org/)."
29 * Alternately, this acknowledgment may appear in the software itself,
30 * if and wherever such third-party acknowledgments normally appear.
31 *
32 * 4. The names "Apache" and "Apache Software Foundation" and
33 * "Apache BCEL" must not be used to endorse or promote products
34 * derived from this software without prior written permission. For
35 * written permission, please contact apache@apache.org.
36 *
37 * 5. Products derived from this software may not be called "Apache",
38 * "Apache BCEL", nor may "Apache" appear in their name, without
39 * prior written permission of the Apache Software Foundation.
40 *
41 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
42 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
43 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
44 * DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
45 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
46 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
47 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
48 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
49 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
50 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
51 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
52 * SUCH DAMAGE.
53 * ====================================================================
54 *
55 * This software consists of voluntary contributions made by many
56 * individuals on behalf of the Apache Software Foundation. For more
57 * information on the Apache Software Foundation, please see
58 * <http://www.apache.org/>.
59 */
60
61 import com.sun.org.apache.bcel.internal.Constants;
62 import java.io.*;
63
64 /**
65 * This class is derived from the abstract
66 * <A HREF="com.sun.org.apache.bcel.internal.classfile.Constant.html">Constant</A> class
67 * and represents a reference to a String object.
68 *
69 * @author <A HREF="mailto:markus.dahm@berlin.de">M. Dahm</A>
70 * @see Constant
71 */
72 public final class ConstantString extends Constant implements ConstantObject {
73 private int string_index; // Identical to ConstantClass except for this name
74
75 /**
76 * Initialize from another object.
77 */
78 public ConstantString(ConstantString c) {
79 this(c.getStringIndex());
80 }
81 /**
82 * Initialize instance from file data.
83 *
84 * @param file Input stream
85 * @throws IOException
86 */
87 ConstantString(DataInputStream file) throws IOException
88 {
89 this((int)file.readUnsignedShort());
90 }
91 /**
92 * @param string_index Index of Constant_Utf8 in constant pool
93 */
94 public ConstantString(int string_index)
95 {
96 super(Constants.CONSTANT_String);
97 this.string_index = string_index;
98 }
99 /**
100 * Called by objects that are traversing the nodes of the tree implicitely
101 * defined by the contents of a Java class. I.e., the hierarchy of methods,
102 * fields, attributes, etc. spawns a tree of objects.
103 *
104 * @param v Visitor object
105 */
106 public void accept(Visitor v) {
107 v.visitConstantString(this);
108 }
109 /**
110 * Dump constant field reference to file stream in binary format.
111 *
112 * @param file Output file stream
113 * @throws IOException
114 */
115 public final void dump(DataOutputStream file) throws IOException
116 {
117 file.writeByte(tag);
118 file.writeShort(string_index);
119 }
120 /**
121 * @return Index in constant pool of the string (ConstantUtf8).
122 */
123 public final int getStringIndex() { return string_index; }
124 /**
125 * @param string_index.
126 */
127 public final void setStringIndex(int string_index) {
128 this.string_index = string_index;
129 }
130 /**
131 * @return String representation.
132 */
133 public final String toString()
134 {
135 return super.toString() + "(string_index = " + string_index + ")";
136 }
137
138 /** @return String object
139 */
140 public Object getConstantValue(ConstantPool cp) {
141 Constant c = cp.getConstant(string_index, Constants.CONSTANT_Utf8);
142 return ((ConstantUtf8)c).getBytes();
143 }
144
145 /** @return dereferenced string
146 */
147 public String getBytes(ConstantPool cp) {
148 return (String)getConstantValue(cp);
149 }
150 }