1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
|
/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*/
package org.apache.tuscany.sca.extensibility;
import java.io.IOException;
import java.lang.ref.WeakReference;
import java.net.URL;
import java.security.AccessController;
import java.security.PrivilegedAction;
import java.security.PrivilegedActionException;
import java.security.PrivilegedExceptionAction;
import java.util.Collection;
import java.util.Collections;
import java.util.Enumeration;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.logging.Level;
import java.util.logging.Logger;
/**
* A ServiceDiscoverer that find META-INF/services/... using the Context ClassLoader.
*
* @version $Rev$ $Date$
*/
public class ContextClassLoaderServiceDiscoverer implements ServiceDiscoverer {
private static final Logger logger = Logger.getLogger(ContextClassLoaderServiceDiscoverer.class.getName());
public class ServiceDeclarationImpl implements ServiceDeclaration {
private URL url;
private String className;
private Class<?> javaClass;
private Map<String, String> attributes;
public ServiceDeclarationImpl(URL url, String className, Map<String, String> attributes) {
super();
this.url = url;
this.className = className;
this.attributes = attributes;
}
public Map<String, String> getAttributes() {
return attributes;
}
public String getClassName() {
return className;
}
public URL getLocation() {
return url;
}
public Class<?> loadClass() throws ClassNotFoundException {
if (className == null) {
return null;
}
if (javaClass == null) {
javaClass = loadClass(className);
}
return javaClass;
}
public Class<?> loadClass(String className) throws ClassNotFoundException {
return Class.forName(className, false, classLoaderReference.get());
}
@Override
public String toString() {
StringBuffer sb = new StringBuffer();
sb.append("Location: ").append(url);
sb.append(" ClassLoader: ").append(classLoaderReference.get());
sb.append(" Attributes: ").append(attributes);
return sb.toString();
}
public URL getResource(final String name) {
return AccessController.doPrivileged(new PrivilegedAction<URL>() {
public URL run() {
return classLoaderReference.get().getResource(name);
}
});
}
public boolean isAssignableTo(Class<?> serviceType) {
try {
loadClass();
} catch (ClassNotFoundException e) {
// Ignore
}
return (javaClass != null && serviceType.isAssignableFrom(javaClass));
}
@Override
public Enumeration<URL> getResources(String name) throws IOException {
return Collections.enumeration(ContextClassLoaderServiceDiscoverer.this.getResources(name));
}
}
private WeakReference<ClassLoader> classLoaderReference;
public ContextClassLoaderServiceDiscoverer() {
ClassLoader classLoader = Thread.currentThread().getContextClassLoader();
this.classLoaderReference = new WeakReference<ClassLoader>(classLoader);
}
public ContextClassLoaderServiceDiscoverer(ClassLoader classLoader) {
if (classLoader == null) {
classLoader = Thread.currentThread().getContextClassLoader();
}
this.classLoaderReference = new WeakReference<ClassLoader>(classLoader);
}
public ClassLoader getContextClassLoader() {
//return classLoaderReference.get();
return Thread.currentThread().getContextClassLoader();
}
private Collection<URL> getResources(final String name) throws IOException {
try {
return AccessController.doPrivileged(new PrivilegedExceptionAction<Collection<URL>>() {
public Collection<URL> run() throws IOException {
List<URL> urls = Collections.list(classLoaderReference.get().getResources(name));
// Eliminate the duplicate URLs (which can be found from child/parent classloaders)
return new HashSet<URL>(urls);
}
});
} catch (PrivilegedActionException e) {
throw (IOException)e.getException();
}
}
public ServiceDeclaration getServiceDeclaration(String name) throws IOException {
Collection<ServiceDeclaration> declarations = getServiceDeclarations(name);
if (declarations.isEmpty()) {
return null;
} else {
return declarations.iterator().next();
}
}
public Collection<ServiceDeclaration> getServiceDeclarations(String serviceName) {
Collection<ServiceDeclaration> descriptors = new HashSet<ServiceDeclaration>();
// http://java.sun.com/j2se/1.5.0/docs/api/javax/xml/xpath/XPathFactory.html
boolean isPropertyFile = "javax.xml.xpath.XPathFactory".equals(serviceName);
String name = serviceName;
if (serviceName.startsWith("/")) {
// If the service name starts with /, treat it as the entry name
name = serviceName.substring(1);
} else {
// Use JDK SPI pattern
name = "META-INF/services/" + serviceName;
}
boolean debug = logger.isLoggable(Level.FINE);
try {
for (final URL url : getResources(name)) {
if (debug) {
logger.fine("Reading service provider file: " + url.toExternalForm());
}
for (Map<String, String> attributes : ServiceDeclarationParser.load(url, isPropertyFile)) {
String className = attributes.get("class");
ServiceDeclarationImpl descriptor = new ServiceDeclarationImpl(url, className, attributes);
descriptors.add(descriptor);
}
}
} catch (IOException e) {
logger.log(Level.SEVERE, e.getMessage(), e);
}
return descriptors;
}
}
|
