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1
22 package org.jboss.virtual.spi;
23
24 import java.io.BufferedReader  ;
25 import java.io.IOException ;
26 import java.io.InputStream ;
27 import java.io.InputStreamReader ;
28 import java.net.URI ;
29 import java.net.URL ;
30 import java.security.AccessController ;
31 import java.security.PrivilegedAction ;
32 import java.util.ArrayList ;
33 import java.util.Arrays ;
34 import java.util.Enumeration ;
35 import java.util.Map ;
36 import java.util.StringTokenizer ;
37 import java.util.concurrent.ConcurrentHashMap ;
38
39 import org.jboss.logging.Logger;
40 import org.jboss.virtual.plugins.context.file.FileSystemContextFactory;
41 import org.jboss.virtual.plugins.context.jar.JarContextFactory;
42
43
50 public class VFSContextFactoryLocator
51 {
52
53 private static final Logger log = Logger.getLogger(VFSContextFactoryLocator.class);
54
55
56 private static final Map <String , VFSContextFactory> factoryByProtocol = new ConcurrentHashMap <String , VFSContextFactory>();
57
58
59 public static final String DEFAULT_FACTORY_PROPERTY = VFSContextFactory.class.getName();
60
61
62 public static final String SERVICES_PATH = "META-INF/services/" + VFSContextFactory.class.getName();
63
64
65 private static boolean initialized;
66
67
75 public synchronized static void registerFactory(VFSContextFactory factory)
76 {
77 if (factory == null)
78 throw new IllegalArgumentException ("Null VFSContextFactory");
79
80 String [] protocols = factory.getProtocols();
81 if (protocols == null || protocols.length == 0)
82 throw new IllegalArgumentException ("VFSContextFactory trying to register null or no protocols: " + factory);
83
84 for (String protocol : protocols)
85 {
86 if (protocol == null)
87 throw new IllegalArgumentException ("VFSContextFactory try to register a null protocol: " + factory + " protocols=" + Arrays.asList(protocols));
88 VFSContextFactory other = factoryByProtocol.get(protocol);
89 if (other != null)
90 throw new IllegalStateException ("VFSContextFactory: " + other + " already registered for protocol: " + protocol);
91 }
92
93 boolean trace = log.isTraceEnabled();
94 for (String protocol : protocols)
95 {
96 factoryByProtocol.put(protocol, factory);
97 if (trace)
98 log.trace("Registered " + factory + " for protocol: " + protocol);
99 }
100 }
101
102
109 public synchronized static boolean unregisterFactory(VFSContextFactory factory)
110 {
111 if (factory == null)
112 throw new IllegalArgumentException ("Null VFSContextFactory");
113
114 ArrayList <String > protocols = new ArrayList <String >();
115 for (Map.Entry <String , VFSContextFactory> entry : factoryByProtocol.entrySet())
116 {
117 if (factory == entry.getValue())
118 protocols.add(entry.getKey());
119 }
120
121 boolean trace = log.isTraceEnabled();
122 for (String protocol : protocols)
123 {
124 factoryByProtocol.remove(protocol);
125 if (trace)
126 log.trace("Unregistered " + factory + " for protocol: " + protocol);
127 }
128
129 return protocols.isEmpty() == false;
130 }
131
132
140 public static VFSContextFactory getFactory(URL rootURL)
141 {
142 if (rootURL == null)
143 throw new IllegalArgumentException ("Null rootURL");
144
145 init();
146 String protocol = rootURL.getProtocol();
147 return factoryByProtocol.get(protocol);
148 }
149
157 public static VFSContextFactory getFactory(URI rootURI)
158 {
159 if (rootURI == null)
160 throw new IllegalArgumentException ("Null rootURI");
161
162 init();
163 String scheme = rootURI.getScheme();
164 return factoryByProtocol.get(scheme);
165 }
166
167
177 private static synchronized void init()
178 {
179 if (initialized)
181 return;
182
183 ClassLoader loader = AccessController.doPrivileged(new GetContextClassLoader());
185 Enumeration <URL > urls = AccessController.doPrivileged(new EnumerateServices());
186 if (urls != null)
187 {
188 while (urls.hasMoreElements())
189 {
190 URL url = urls.nextElement();
191
192 VFSContextFactory[] factories = loadFactories(url, loader);
193 for (VFSContextFactory factory : factories)
194 {
195 try
196 {
197 registerFactory(factory);
198 }
199 catch (Exception e)
200 {
201 log.warn("Error registering factory from " + url, e);
202 }
203 }
204 }
205 }
206
207 String defaultFactoryNames = AccessController.doPrivileged(new GetDefaultFactories());
208 if (defaultFactoryNames != null)
209 {
210 StringTokenizer tokenizer = new StringTokenizer (defaultFactoryNames, ",");
211 while (tokenizer.hasMoreTokens())
212 {
213 String factoryName = tokenizer.nextToken();
214 VFSContextFactory factory = createVFSContextFactory(loader, factoryName, " from system property.");
215 if (factory != null)
216 registerFactory(factory);
217 }
218 }
219
220 if (factoryByProtocol.containsKey("file") == false)
222 registerFactory(new FileSystemContextFactory());
223
224 if (factoryByProtocol.containsKey("jar") == false)
226 registerFactory(new JarContextFactory());
227
228 initialized = true;
229 }
230
231
239 private static VFSContextFactory[] loadFactories(URL serviceURL, ClassLoader loader)
240 {
241 ArrayList <VFSContextFactory> temp = new ArrayList <VFSContextFactory>();
242 try
243 {
244 InputStream is = serviceURL.openStream();
245 try
246 {
247 BufferedReader br = new BufferedReader (new InputStreamReader (is));
248 String line;
249 while ( (line = br.readLine()) != null )
250 {
251 if (line.startsWith("#") == true)
252 continue;
253 String [] classes = line.split("\\s+|#.*");
254 for (int n = 0; n < classes.length; n ++)
255 {
256 String name = classes[n];
257 if (name.length() == 0)
258 continue;
259 VFSContextFactory factory = createVFSContextFactory(loader, name, " defined in " + serviceURL);
260 if (factory != null)
261 temp.add(factory);
262 }
263 }
264 }
265 finally
266 {
267 is.close();
268 }
269 }
270 catch(Exception e)
271 {
272 log.warn("Error parsing " + serviceURL, e);
273 }
274
275 VFSContextFactory[] factories = new VFSContextFactory[temp.size()];
276 return temp.toArray(factories);
277 }
278
279
286 private static VFSContextFactory createVFSContextFactory(ClassLoader cl, String className, String context)
287 {
288 try
289 {
290 Class factoryClass = cl.loadClass(className);
291 return (VFSContextFactory) factoryClass.newInstance();
292 }
293 catch (Exception e)
294 {
295 log.warn("Error creating VFSContextFactory " + className + " " + context, e);
296 return null;
297 }
298 }
299
300
303 private static class GetContextClassLoader implements PrivilegedAction <ClassLoader >
304 {
305 public ClassLoader run()
306 {
307 return Thread.currentThread().getContextClassLoader();
308 }
309 }
310
311
314 private static class GetDefaultFactories implements PrivilegedAction <String >
315 {
316 public String run()
317 {
318 return System.getProperty(DEFAULT_FACTORY_PROPERTY);
319 }
320 }
321
322
325 private static class EnumerateServices implements PrivilegedAction <Enumeration <URL >>
326 {
327 public Enumeration <URL > run()
328 {
329 ClassLoader cl = Thread.currentThread().getContextClassLoader();
330 try
331 {
332 return cl.getResources(SERVICES_PATH);
333 }
334 catch (IOException e)
335 {
336 log.warn("Error retrieving " + SERVICES_PATH, e);
337 return null;
338 }
339 }
340 }
341 }
342 |
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