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Java > Open Source Codes > test > aopc > ClassCreator


1 /**************************************************************************************
2  * Copyright (c) Jonas Bon?r, Alexandre Vasseur. All rights reserved. *
3  * http://aspectwerkz.codehaus.org *
4  * ---------------------------------------------------------------------------------- *
5  * The software in this package is published under the terms of the LGPL license *
6  * a copy of which has been included with this distribution in the license.txt file. *
7  **************************************************************************************/
8 package test.aopc;
9
10 import org.codehaus.aspectwerkz.exception.WrappedRuntimeException;
11
12 import java.io.File JavaDoc;
13 import java.lang.reflect.Array JavaDoc;
14 import java.lang.reflect.Method JavaDoc;
15 import java.net.MalformedURLException JavaDoc;
16 import java.net.URL JavaDoc;
17 import java.net.URLClassLoader JavaDoc;
18
19 /**
20  * Test helper for AspectContainer, emulates a ClassLoader hierarchy sys/sub/ sys/sub/a sys/sub/b
21  *
22  * FIXME - rewrite with ASM
23  *
24  * @author <a HREF="mailto:alex@gnilux.com">Alexandre Vasseur </a>
25  */
26 public class ClassCreator {
27     /**
28      * ClassLoader.defineClass(name, bytes, from, to)
29      */
30     private static Method JavaDoc CLASSLOADER_DEFINECLASS_METHOD;
31
32     static {
33         try {
34             Object JavaDoc b = Array.newInstance(byte.class, 1);
35             CLASSLOADER_DEFINECLASS_METHOD = ClassLoader JavaDoc.class.getDeclaredMethod(
36                     "defineClass",
37                     new Class JavaDoc[]{
38                         String JavaDoc.class, b.getClass(), int.class, int.class
39                     }
40             );
41             CLASSLOADER_DEFINECLASS_METHOD.setAccessible(true);
42         } catch (Throwable JavaDoc t) {
43             t.printStackTrace();
44         }
45     }
46
47     public static Object JavaDoc createInstance(String JavaDoc name, Class JavaDoc classPrototype, ClassLoader JavaDoc loader) {
48         try {
49             return createClass(name, classPrototype, loader).newInstance();
50         } catch (Throwable JavaDoc t) {
51             throw new WrappedRuntimeException(t);
52         }
53     }
54
55     public static Class JavaDoc createClass(String JavaDoc name, Class JavaDoc classPrototype, ClassLoader JavaDoc loader) {
56         return classPrototype;
57 // try {
58 // ClassPool cp = new ClassPool(null);
59 // cp.appendClassPath(new LoaderClassPath(loader));
60 // CtClass prototype = cp.get(classPrototype.getName());
61 // prototype.setName(name);
62 // return define(prototype.toBytecode(), name, loader);
63 // } catch (Throwable throwable) {
64 // throw new WrappedRuntimeException(throwable);
65 // }
66 }
67
68     public static void main(String JavaDoc[] a) throws Throwable JavaDoc {
69         ClassLoader JavaDoc myCL = new URLClassLoader JavaDoc(
70                 new URL JavaDoc[]{
71                     getPathFor(Callable.class.getResource("META-INF/aop.xml"))
72                 }, ClassLoader.getSystemClassLoader()
73         );
74         ClassLoader JavaDoc mySubCLA = new URLClassLoader JavaDoc(
75                 new URL JavaDoc[]{
76                     getPathFor(Callable.class.getResource("a/META-INF/aop.xml"))
77                 }, myCL
78         );
79         Callable ca = (Callable) (createClass("test.aopc.a.Callee", CallablePrototype.class, mySubCLA)).newInstance();
80         ca.methodAround();
81         ca.debug();
82         ClassLoader JavaDoc mySubCLB = new URLClassLoader JavaDoc(new URL JavaDoc[]{}, myCL);
83         Callable cb = (Callable) (createClass("test.aopc.b.Callee", CallablePrototype.class, mySubCLB)).newInstance();
84         cb.methodAround();
85         cb.debug();
86     }
87
88     public static URL JavaDoc getPathFor(URL JavaDoc definition) {
89         try {
90             System.out.println(definition);
91             System.out.println(definition.getFile());
92             File JavaDoc f = new File JavaDoc(definition.getFile());
93             if (!f.exists()) {
94                 System.err.println("<WARN> could not find " + f);
95             }
96             String JavaDoc path = new File JavaDoc(f.getParent()).getParent();
97             File JavaDoc testExists = new File JavaDoc(path);
98             if (!testExists.isDirectory()) {
99                 System.err.println("<WARN> could not find " + path);
100             }
101             return new File JavaDoc(path).toURL();
102         } catch (MalformedURLException JavaDoc e) {
103             throw new WrappedRuntimeException(e);
104         }
105     }
106
107     /**
108      * Helper to define a Class within a specific ClassLoader
109      *
110      * @param b
111      * @param name
112      * @param loader
113      * @return @throws Throwable
114      */
115     public static Class JavaDoc define(byte[] b, String JavaDoc name, ClassLoader JavaDoc loader) throws Throwable JavaDoc {
116         Object JavaDoc k = CLASSLOADER_DEFINECLASS_METHOD.invoke(
117                 loader, new Object JavaDoc[]{
118                     name, b, new Integer JavaDoc(0), new Integer JavaDoc(b.length)
119                 }
120         );
121         return (Class JavaDoc) k;
122     }
123 }
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