1 package org.sentrysoftware.jawk.util;
2
3 /*-
4 * ╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲
5 * Jawk
6 * ჻჻჻჻჻჻
7 * Copyright (C) 2006 - 2023 Sentry Software
8 * ჻჻჻჻჻჻
9 * This program is free software: you can redistribute it and/or modify
10 * it under the terms of the GNU Lesser General Public License as
11 * published by the Free Software Foundation, either version 3 of the
12 * License, or (at your option) any later version.
13 *
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 * GNU General Lesser Public License for more details.
18 *
19 * You should have received a copy of the GNU General Lesser Public
20 * License along with this program. If not, see
21 * <http://www.gnu.org/licenses/lgpl-3.0.html>.
22 * ╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱╲╱
23 */
24
25 import java.io.ByteArrayOutputStream;
26 import java.io.File;
27 import java.io.FileInputStream;
28 import java.io.IOException;
29
30 /**
31 * Load classes from a particular directory, disregarding the
32 * environmental class-path setting.
33 * This is useful when a directory is specified for class files,
34 * and it would not make sense to deviate from that directory.
35 * So this ClassLoader does practically the same
36 * like a <code>URLClassLoader</code> with a "file://.../" URL,
37 * except that it does not forward calls to its parent,
38 * if it can not find the class its self.
39 * <p>
40 * For Jawk, this is used when the -d argument is present.
41 *
42 * @author Danny Daglas
43 */
44 public final class DestDirClassLoader extends ClassLoader {
45
46 private String dirname;
47
48 /**
49 * <p>Constructor for DestDirClassLoader.</p>
50 *
51 * @param dirname a {@link java.lang.String} object
52 */
53 public DestDirClassLoader(String dirname) {
54 this.dirname = dirname;
55 }
56
57 /** {@inheritDoc} */
58 @Override
59 protected Class<?> findClass(String name)
60 throws ClassNotFoundException
61 {
62 byte[] b = loadClassData(name);
63 return defineClass(name, b, 0, b.length);
64 }
65
66 private byte[] loadClassData(String name)
67 throws ClassNotFoundException
68 {
69 String fileName = dirname + File.separator + name + ".class";
70 try {
71 FileInputStream f = new FileInputStream(fileName);
72 ByteArrayOutputStream baos = new ByteArrayOutputStream();
73 byte[] b = new byte[4096];
74 int len;
75 while ((len = f.read(b, 0, b.length)) >= 0) {
76 baos.write(b, 0, len);
77 }
78 f.close();
79 baos.close();
80 return baos.toByteArray();
81 } catch (IOException ioe) {
82 throw new ClassNotFoundException(
83 "Could not load class " + name
84 + " from file \"" + fileName + "\"", ioe);
85 }
86 }
87 }