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8 package org.xml.sax.helpers;
9
10 import java.lang.reflect.Method;
11 import java.lang.reflect.InvocationTargetException;
12
13 /***
14 * Create a new instance of a class by name.
15 *
16 * <blockquote>
17 * <em>This module, both source code and documentation, is in the
18 * Public Domain, and comes with <strong>NO WARRANTY</strong>.</em>
19 * See <a href='http://www.saxproject.org'>http://www.saxproject.org</a>
20 * for further information.
21 * </blockquote>
22 *
23 * <p>This class contains a static method for creating an instance of a
24 * class from an explicit class name. It tries to use the thread's context
25 * ClassLoader if possible and falls back to using
26 * Class.forName(String).</p>
27 *
28 * <p>This code is designed to compile and run on JDK version 1.1 and later
29 * including versions of Java 2.</p>
30 *
31 * @author Edwin Goei, David Brownell
32 * @version 2.0.1 (sax2r2)
33 */
34 class NewInstance {
35
36 /***
37 * Creates a new instance of the specified class name
38 *
39 * Package private so this code is not exposed at the API level.
40 */
41 static Object newInstance (ClassLoader classLoader, String className)
42 throws ClassNotFoundException, IllegalAccessException,
43 InstantiationException
44 {
45 Class driverClass;
46 if (classLoader == null) {
47 driverClass = Class.forName(className);
48 } else {
49 driverClass = classLoader.loadClass(className);
50 }
51 return driverClass.newInstance();
52 }
53
54 /***
55 * Figure out which ClassLoader to use. For JDK 1.2 and later use
56 * the context ClassLoader.
57 */
58 static ClassLoader getClassLoader ()
59 {
60 Method m = null;
61
62 try {
63 m = Thread.class.getMethod("getContextClassLoader", null);
64 } catch (NoSuchMethodException e) {
65
66 return NewInstance.class.getClassLoader();
67 }
68
69 try {
70 return (ClassLoader) m.invoke(Thread.currentThread(), null);
71 } catch (IllegalAccessException e) {
72
73 throw new UnknownError(e.getMessage());
74 } catch (InvocationTargetException e) {
75
76 throw new UnknownError(e.getMessage());
77 }
78 }
79 }