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Java > Open Source Codes > javassist > ByteArrayClassPath


1 /*
2  * Javassist, a Java-bytecode translator toolkit.
3  * Copyright (C) 1999-2005 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
16 package javassist;
17
18 import java.io.*;
19 import java.net.URL JavaDoc;
20 import java.net.MalformedURLException JavaDoc;
21
22 /**
23  * A <code>ByteArrayClassPath</code> contains bytes that is served as
24  * a class file to a <code>ClassPool</code>. It is useful to convert
25  * a byte array to a <code>CtClass</code> object.
26  *
27  * <p>For example, if you want to convert a byte array <code>b</code>
28  * into a <code>CtClass</code> object representing the class with a name
29  * <code>classname</code>, then do as following:
30  *
31  * <ul><pre>
32  * ClassPool cp = ClassPool.getDefault();
33  * cp.insertClassPath(new ByteArrayClassPath(classname, b));
34  * CtClass cc = cp.get(classname);
35  * </pre></ul>
36  *
37  * <p>The <code>ClassPool</code> object <code>cp</code> uses the created
38  * <code>ByteArrayClassPath</code> object as the source of the class file.
39  *
40  * <p>A <code>ByteArrayClassPath</code> must be instantiated for every
41  * class. It contains only a single class file.
42  *
43  * @see javassist.ClassPath
44  * @see ClassPool#insertClassPath(ClassPath)
45  * @see ClassPool#appendClassPath(ClassPath)
46  * @see ClassPool#makeClass(InputStream)
47  */
48 public class ByteArrayClassPath implements ClassPath {
49     protected String JavaDoc classname;
50     protected byte[] classfile;
51
52     /*
53      * Creates a <code>ByteArrayClassPath</code> containing the given
54      * bytes.
55      *
56      * @param name a fully qualified class name
57      * @param classfile the contents of a class file.
58      */
59     public ByteArrayClassPath(String JavaDoc name, byte[] classfile) {
60         this.classname = name;
61         this.classfile = classfile;
62     }
63
64     /**
65      * Closes this class path.
66      */
67     public void close() {}
68
69     public String JavaDoc toString() {
70         return "byte[]:" + classname;
71     }
72
73     /**
74      * Opens the class file.
75      */
76     public InputStream openClassfile(String JavaDoc classname) {
77         if(this.classname.equals(classname))
78             return new ByteArrayInputStream(classfile);
79         else
80             return null;
81     }
82
83     /**
84      * Obtains the URL.
85      */
86     public URL JavaDoc find(String JavaDoc classname) {
87         if(this.classname.equals(classname)) {
88             String JavaDoc cname = classname.replace('.', '/') + ".class";
89             try {
90                 // return new File(cname).toURL();
91 return new URL JavaDoc("file:/ByteArrayClassPath/" + cname);
92             }
93             catch (MalformedURLException JavaDoc e) {}
94         }
95
96         return null;
97     }
98 }
99
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