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1
5 package com.tc.object.loaders;
6
7 import com.tc.aspectwerkz.transform.inlining.AsmHelper;
8
9 import java.lang.ref.WeakReference  ;
10 import java.util.HashMap ;
11 import java.util.Map ;
12
13 public class StandardClassProvider implements ClassProvider {
14
15 private static final String BOOT = Namespace.getStandardBootstrapLoaderName();
16 private static final String EXT = Namespace.getStandardExtensionsLoaderName();
17 private static final String SYSTEM = Namespace.getStandardSystemLoaderName();
18
19 private final ClassLoader systemLoader = ClassLoader.getSystemClassLoader();
20 private final Map loaders = new HashMap ();
21
22 public StandardClassProvider() {
23 }
25
26 public ClassLoader getClassLoader(String desc) {
27 if (isStandardLoader(desc)) { return systemLoader; }
28
29 ClassLoader rv = lookupLoader(desc);
30 if (rv == null) { throw new AssertionError ("No registered loader for description: " + desc); }
31 return rv;
32 }
33
34 public Class getClassFor(final String className, String desc) throws ClassNotFoundException {
35 final ClassLoader loader;
36
37 if (isStandardLoader(desc)) {
38 loader = systemLoader;
39 } else {
40 loader = lookupLoader(desc);
41 if (loader == null) { throw new ClassNotFoundException ("No registered loader for description: " + desc
42 + ", trying to load " + className); }
43 }
44
45 try {
46 return Class.forName(className, false, loader);
47 } catch (ClassNotFoundException e) {
48 if (loader instanceof BytecodeProvider) {
49 BytecodeProvider provider = (BytecodeProvider) loader;
50 byte[] bytes = provider.__tc_getBytecodeForClass(className);
51 if (bytes != null && bytes.length != 0) { return AsmHelper.defineClass(loader, bytes, className); }
52 }
53 throw e;
54 }
55 }
56
57 public void registerNamedLoader(NamedClassLoader loader) {
58 final String name = getName(loader);
59 synchronized (loaders) {
60 loaders.put(name, new WeakReference (loader));
61 }
62 }
63
64 private static String getName(NamedClassLoader loader) {
65 String name = loader.__tc_getClassLoaderName();
66 if (name == null || name.length() == 0) { throw new AssertionError ("Invalid name [" + name + "] from loader "
67 + loader); }
68 return name;
69 }
70
71 public String getLoaderDescriptionFor(Class clazz) {
72 return getLoaderDescriptionFor(clazz.getClassLoader());
73 }
74
75 public String getLoaderDescriptionFor(ClassLoader loader) {
76 if (loader == null) { return BOOT; }
77 if (loader instanceof NamedClassLoader) { return getName((NamedClassLoader) loader); }
78 throw handleMissingLoader(loader);
79 }
80
81 private RuntimeException handleMissingLoader(ClassLoader loader) {
82 if ("org.apache.jasper.servlet.JasperLoader".equals(loader.getClass().getName())) {
83 return new RuntimeException ("JSP instances (and inner classes there of) cannot be distributed, loader = "
85 + loader);
86 }
87 return new RuntimeException ("No loader description for " + loader);
88 }
89
90 private boolean isStandardLoader(String desc) {
91 if (BOOT.equals(desc) || EXT.equals(desc) || SYSTEM.equals(desc)) { return true; }
92 return false;
93 }
94
95 private ClassLoader lookupLoader(String desc) {
96 final ClassLoader rv;
97 synchronized (loaders) {
98 WeakReference ref = (WeakReference ) loaders.get(desc);
99 if (ref != null) {
100 rv = (ClassLoader ) ref.get();
101 if (rv == null) {
102 loaders.remove(desc);
103 }
104 } else {
105 rv = null;
106 }
107 }
108 return rv;
109 }
110 }
111 |
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