1 //
2 // ========================================================================
3 // Copyright (c) 1995-2013 Mort Bay Consulting Pty. Ltd.
4 // ------------------------------------------------------------------------
5 // All rights reserved. This program and the accompanying materials
6 // are made available under the terms of the Eclipse Public License v1.0
7 // and Apache License v2.0 which accompanies this distribution.
8 //
9 // The Eclipse Public License is available at
10 // http://www.eclipse.org/legal/epl-v10.html
11 //
12 // The Apache License v2.0 is available at
13 // http://www.opensource.org/licenses/apache2.0.php
14 //
15 // You may elect to redistribute this code under either of these licenses.
16 // ========================================================================
17 //
18
19 package org.eclipse.jetty.jndi;
20
21
22 import java.io.IOException;
23 import java.util.Hashtable;
24 import java.util.Map;
25 import java.util.WeakHashMap;
26
27 import javax.naming.Context;
28 import javax.naming.Name;
29 import javax.naming.NameParser;
30 import javax.naming.Reference;
31 import javax.naming.StringRefAddr;
32 import javax.naming.spi.ObjectFactory;
33
34 import org.eclipse.jetty.server.handler.ContextHandler;
35 import org.eclipse.jetty.util.log.Logger;
36
37
38
39 /**
40 * ContextFactory.java
41 *
42 * This is an object factory that produces a jndi naming
43 * context based on a classloader.
44 *
45 * It is used for the java:comp context.
46 *
47 * This object factory is bound at java:comp. When a
48 * lookup arrives for java:comp, this object factory
49 * is invoked and will return a context specific to
50 * the caller's environment (so producing the java:comp/env
51 * specific to a webapp).
52 *
53 * The context selected is based on classloaders. First
54 * we try looking at the thread context classloader if it is set, and walk its
55 * hierarchy, creating a context if none is found. If the thread context classloader
56 * is not set, then we use the classloader associated with the current Context.
57 *
58 * If there is no current context, or no classloader, we return null.
59 *
60 * Created: Fri Jun 27 09:26:40 2003
61 *
62 *
63 *
64 */
65 public class ContextFactory implements ObjectFactory
66 {
67 private static Logger __log = NamingUtil.__log;
68
69 /**
70 * Map of classloaders to contexts.
71 */
72 private static final WeakHashMap __contextMap = new WeakHashMap();
73
74 /**
75 * Threadlocal for injecting a context to use
76 * instead of looking up the map.
77 */
78 private static final ThreadLocal __threadContext = new ThreadLocal();
79
80
81 /**
82 * Find or create a context which pertains to a classloader.
83 *
84 * If the thread context classloader is set, we try to find an already-created naming context
85 * for it. If one does not exist, we walk its classloader hierarchy until one is found, or we
86 * run out of parent classloaders. In the latter case, we will create a new naming context associated
87 * with the original thread context classloader.
88 *
89 * If the thread context classloader is not set, we obtain the classloader from the current
90 * jetty Context, and look for an already-created naming context.
91 *
92 * If there is no current jetty Context, or it has no associated classloader, we
93 * return null.
94 * @see javax.naming.spi.ObjectFactory#getObjectInstance(java.lang.Object, javax.naming.Name, javax.naming.Context, java.util.Hashtable)
95 */
96 public Object getObjectInstance (Object obj,
97 Name name,
98 Context nameCtx,
99 Hashtable env)
100 throws Exception
101 {
102 //First, see if we have had a context injected into us to use.
103 Context ctx = (Context)__threadContext.get();
104 if (ctx != null)
105 {
106 if(__log.isDebugEnabled()) __log.debug("Using the Context that is bound on the thread");
107 return ctx;
108 }
109
110
111 ClassLoader tccl = Thread.currentThread().getContextClassLoader();
112 ClassLoader loader = tccl;
113 //If the thread context classloader is set, then try its hierarchy to find a matching context
114 if (loader != null)
115 {
116 if (__log.isDebugEnabled() && loader != null) __log.debug("Trying thread context classloader");
117 while (ctx == null && loader != null)
118 {
119 ctx = getContextForClassLoader(loader);
120 if (ctx == null && loader != null)
121 loader = loader.getParent();
122 }
123
124 if (ctx == null)
125 {
126 ctx = newNamingContext(obj, tccl, env, name, nameCtx);
127 __contextMap.put (tccl, ctx);
128 if(__log.isDebugEnabled())__log.debug("Made context "+name.get(0)+" for classloader: "+tccl);
129 }
130 return ctx;
131 }
132
133
134 //If trying thread context classloader hierarchy failed, try the
135 //classloader associated with the current context
136 if (ContextHandler.getCurrentContext() != null)
137 {
138
139 if (__log.isDebugEnabled() && loader != null) __log.debug("Trying classloader of current org.eclipse.jetty.server.handler.ContextHandler");
140 loader = ContextHandler.getCurrentContext().getContextHandler().getClassLoader();
141 ctx = (Context)__contextMap.get(loader);
142
143 if (ctx == null && loader != null)
144 {
145 ctx = newNamingContext(obj, loader, env, name, nameCtx);
146 __contextMap.put (loader, ctx);
147 if(__log.isDebugEnabled())__log.debug("Made context "+name.get(0)+" for classloader: "+loader);
148 }
149
150 return ctx;
151 }
152 return null;
153 }
154
155
156 /**
157 * Create a new NamingContext.
158 * @param obj
159 * @param loader
160 * @param env
161 * @param name
162 * @param parentCtx
163 * @return
164 * @throws Exception
165 */
166 public NamingContext newNamingContext(Object obj, ClassLoader loader, Hashtable env, Name name, Context parentCtx)
167 throws Exception
168 {
169 Reference ref = (Reference)obj;
170 StringRefAddr parserAddr = (StringRefAddr)ref.get("parser");
171 String parserClassName = (parserAddr==null?null:(String)parserAddr.getContent());
172 NameParser parser = (NameParser)(parserClassName==null?null:loader.loadClass(parserClassName).newInstance());
173
174 return new NamingContext (env,
175 name.get(0),
176 (NamingContext)parentCtx,
177 parser);
178 }
179
180
181 /**
182 * Find the naming Context for the given classloader
183 * @param loader
184 * @return
185 */
186 public Context getContextForClassLoader(ClassLoader loader)
187 {
188 if (loader == null)
189 return null;
190
191 return (Context)__contextMap.get(loader);
192 }
193
194
195 /**
196 * Associate the given Context with the current thread.
197 * resetComponentContext method should be called to reset the context.
198 * @param ctx the context to associate to the current thread.
199 * @return the previous context associated on the thread (can be null)
200 */
201 public static Context setComponentContext(final Context ctx)
202 {
203 Context previous = (Context)__threadContext.get();
204 __threadContext.set(ctx);
205 return previous;
206 }
207
208 /**
209 * Set back the context with the given value.
210 * Don't return the previous context, use setComponentContext() method for this.
211 * @param ctx the context to associate to the current thread.
212 */
213 public static void resetComponentContext(final Context ctx)
214 {
215 __threadContext.set(ctx);
216 }
217
218 public static void dump(Appendable out, String indent) throws IOException
219 {
220 out.append("o.e.j.jndi.ContextFactory@").append(Long.toHexString(__contextMap.hashCode())).append("\n");
221 int size=__contextMap.size();
222 int i=0;
223 for (Map.Entry<ClassLoader,NamingContext> entry : ((Map<ClassLoader,NamingContext>)__contextMap).entrySet())
224 {
225 boolean last=++i==size;
226 ClassLoader loader=entry.getKey();
227 out.append(indent).append(" +- ").append(loader.getClass().getSimpleName()).append("@").append(Long.toHexString(loader.hashCode())).append(": ");
228
229 NamingContext context = entry.getValue();
230 context.dump(out,indent+(last?" ":" | "));
231 }
232 }
233
234 }