ClassLoaderTarg.java revision 0:37a05a11f281 
1/*
2 * Copyright 2001 Sun Microsystems, Inc.  All Rights Reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
20 * CA 95054 USA or visit www.sun.com if you need additional information or
21 * have any questions.
22 */
23
24/**
25 *
26 */
27import java.util.*;
28import java.io.*;
29
30class ClassLoaderTarg extends ClassLoader {
31    private Hashtable loaded = new Hashtable();
32    String id;
33
34    public ClassLoaderTarg(String id) {
35        this.id = id;
36    }
37
38    private byte[] loadClassBytes(String cname)
39                                         throws ClassNotFoundException {
40        StringTokenizer stk = new StringTokenizer(System.getProperty("java.class.path"),
41                                                  File.pathSeparator);
42        /* search class path for the class file */
43        while (stk.hasMoreTokens()) {
44           File cfile = new File(stk.nextToken() + File.separator +
45                                 cname + ".class");
46           if (cfile.exists()) {
47               System.out.println("loading from: " + cfile);
48               return loadBytes(cfile, cname);
49           } else {
50               System.out.println("no file: " + cfile + " - trying next");
51           }
52        }
53        throw new ClassNotFoundException(cname);
54    }
55
56
57    private byte[] loadBytes(File cfile, String cname)
58                                         throws ClassNotFoundException {
59        try {
60            long fsize = cfile.length();
61            if (fsize > 0) {
62                FileInputStream in = new FileInputStream(cfile);
63                byte[] cbytes = new byte[(int)fsize];
64                in.read(cbytes);
65                in.close();
66                return cbytes;
67            }
68        } catch (IOException exc) {
69            // drop down
70        }
71        throw new ClassNotFoundException(cname);
72    }
73
74    public synchronized Class findClass(String cname)
75                                     throws ClassNotFoundException {
76        Class klass = (Class)loaded.get(cname);
77        if (klass == null) {
78            byte[] cbytes = loadClassBytes(cname);
79            klass = defineClass(cname, cbytes, 0, cbytes.length);
80            loaded.put(cname, klass);
81            System.err.println("ClassLoaderTarg (" + id +") loaded: " + cname);
82        }
83        return klass;
84    }
85
86    protected void finalize() {
87        UnloadEventTarg.classLoaderFinalized(id);
88        try {
89            super.finalize();
90        } catch (Throwable thrown) {
91        }
92    }
93}
94