1/*
2 * Javassist, a Java-bytecode translator toolkit.
3 * Copyright (C) 1999-2007 Shigeru Chiba. All Rights Reserved.
4 *
5 * The contents of this file are subject to the Mozilla Public License Version
6 * 1.1 (the "License"); you may not use this file except in compliance with
7 * the License.  Alternatively, the contents of this file may be used under
8 * the terms of the GNU Lesser General Public License Version 2.1 or later.
9 *
10 * Software distributed under the License is distributed on an "AS IS" basis,
11 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
12 * for the specific language governing rights and limitations under the
13 * License.
14 */
15
16package javassist.bytecode;
17
18import java.io.DataInputStream;
19import java.util.Map;
20import java.io.IOException;
21
22/**
23 * <code>ConstantValue_attribute</code>.
24 */
25public class ConstantAttribute extends AttributeInfo {
26    /**
27     * The name of this attribute <code>"ConstantValue"</code>.
28     */
29    public static final String tag = "ConstantValue";
30
31    ConstantAttribute(ConstPool cp, int n, DataInputStream in)
32        throws IOException
33    {
34        super(cp, n, in);
35    }
36
37    /**
38     * Constructs a ConstantValue attribute.
39     *
40     * @param cp                a constant pool table.
41     * @param index             <code>constantvalue_index</code>
42     *                          of <code>ConstantValue_attribute</code>.
43     */
44    public ConstantAttribute(ConstPool cp, int index) {
45        super(cp, tag);
46        byte[] bvalue = new byte[2];
47        bvalue[0] = (byte)(index >>> 8);
48        bvalue[1] = (byte)index;
49        set(bvalue);
50    }
51
52    /**
53     * Returns <code>constantvalue_index</code>.
54     */
55    public int getConstantValue() {
56        return ByteArray.readU16bit(get(), 0);
57    }
58
59    /**
60     * Makes a copy.  Class names are replaced according to the
61     * given <code>Map</code> object.
62     *
63     * @param newCp     the constant pool table used by the new copy.
64     * @param classnames        pairs of replaced and substituted
65     *                          class names.
66     */
67    public AttributeInfo copy(ConstPool newCp, Map classnames) {
68        int index = getConstPool().copy(getConstantValue(), newCp,
69                                        classnames);
70        return new ConstantAttribute(newCp, index);
71    }
72}
73