TCLFilter


1   /*
2     * JBoss, Home of Professional Open Source
3     * Copyright 2005, JBoss Inc., and individual contributors as indicated
4     * by the @authors tag. See the copyright.txt in the distribution for a
5     * full listing of individual contributors.
6     *
7     * This is free software; you can redistribute it and/or modify it
8     * under the terms of the GNU Lesser General Public License as
9     * published by the Free Software Foundation; either version 2.1 of
10    * the License, or (at your option) any later version.
11    *
12    * This software is distributed in the hope that it will be useful,
13    * but WITHOUT ANY WARRANTY; without even the implied warranty of
14    * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15    * Lesser General Public License for more details.
16    *
17    * You should have received a copy of the GNU Lesser General Public
18    * License along with this software; if not, write to the Free
19    * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
20    * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
21    */
22  package org.jboss.logging.filter;
23  
24  
25  
26  import java.lang.reflect.Method  ;
27  
28  import java.net.URL  ;
29  
30  
31  
32  import org.apache.log4j.spi.Filter;
33  
34  import org.apache.log4j.spi.LoggingEvent;
35  
36  
37  
38  import org.jboss.util.collection.WeakSet;
39  
40  
41  
42  /** An appender filter that accepts log events based on whether the thread
43  
44   context class loader has a classpath URL that has the DeployURL
45  
46   attribute as a substring. A sample usage would be:
47  
48  
49  
50     <appender name="JMX-CONSOLE" class="org.jboss.logging.appender.FileAppender">
51  
52        <errorHandler class="org.jboss.logging.util.OnlyOnceErrorHandler"/>
53  
54        <param name="File" value="${jboss.server.home.dir}/log/jmx-console.log"/>
55  
56        <layout class="org.apache.log4j.PatternLayout">
57  
58           <!-- The default pattern: Date Priority [Category] Message\n -->
59  
60           <param name="ConversionPattern" value="%d %-5p [%c] %m%n"/>
61  
62        </layout>
63  
64        <filter class="org.jboss.logging.filter.TCLFilter">
65  
66           <param name="AcceptOnMatch" value="true"/>
67  
68           <param name="DeployURL" value="jmx-console.war"/>
69  
70        </filter>
71  
72     </appender>
73  
74  
75  
76   @author Scott.Stark@jboss.org
77  
78   @version $Revison:$
79  
80   */
81  
82  public class TCLFilter extends Filter
83  
84  {
85  
86     /** The set of TCLs seen to match DeployURL */
87  
88     private WeakSet matchSet = new WeakSet();
89  
90     /** The set of TCLs seen to not match DeployURL */
91  
92     private WeakSet missSet = new WeakSet();
93  
94     /** The deployment URL string fragment to match against */
95  
96     private String   deployURL;
97  
98     /** Whether a match should return ACCEPT or DENY */
99  
100    private boolean acceptOnMatch = true;
101 
102 
103 
104    public boolean isAcceptOnMatch()
105 
106    {
107 
108       return acceptOnMatch;
109 
110    }
111 
112    public void setAcceptOnMatch(boolean acceptOnMatch)
113 
114    {
115 
116       this.acceptOnMatch = acceptOnMatch;
117 
118    }
119 
120    public String   getDeployURL()
121 
122    {
123 
124       return deployURL;
125 
126    }
127 
128    public void setDeployURL(String   deployURL)
129 
130    {
131 
132       this.deployURL = deployURL;
133 
134    }
135 
136 
137 
138    public int decide(LoggingEvent event)
139 
140    {
141 
142       int ok = Filter.DENY;
143 
144       if( acceptOnMatch == true )
145 
146       {
147 
148          ok = Filter.DENY;
149 
150          if( isMatchingTCL() )
151 
152             ok = Filter.ACCEPT;
153 
154       }
155 
156       else
157 
158       {
159 
160          ok = Filter.ACCEPT;
161 
162          if( isMatchingTCL() )
163 
164             ok = Filter.DENY;
165 
166       }
167 
168       return ok;
169 
170    }
171 
172 
173 
174    /** Start with the current thread context class loader 
175 
176     * @return true if the caller tcl has a url matching our deployURL
177 
178     */ 
179 
180    private boolean isMatchingTCL()
181 
182    {
183 
184       ClassLoader   tcl = Thread.currentThread().getContextClassLoader();
185 
186       if( matchSet.contains(tcl) )
187 
188          return true;
189 
190       if( missSet.contains(tcl) )
191 
192          return false;
193 
194 
195 
196       // Search the class loader URLs for a match
197 
198       ClassLoader   cl = tcl;
199 
200       boolean match = false;
201 
202       while( cl != null )
203 
204       {
205 
206          URL  [] urls = getClassLoaderURLs(cl);
207 
208          for(int n = 0; n < urls.length; n ++)
209 
210          {
211 
212             URL   u = urls[n];
213 
214             String   file = u.getFile();
215 
216             if( file.indexOf(deployURL) > 0 )
217 
218             {
219 
220                match = true;
221 
222                break;
223 
224             }
225 
226          }
227 
228          cl = cl.getParent();
229 
230       }
231 
232       if( match == true )
233 
234          matchSet.add(tcl);
235 
236       else
237 
238          missSet.add(tcl);
239 
240 
241 
242       return match;
243 
244    }
245 
246 
247 
248    /** Use reflection to access a URL[] getURLs method so that non-URLClassLoader
249 
250     class loaders that support this method can provide info.
251 
252     */
253 
254    private static URL  [] getClassLoaderURLs(ClassLoader   cl)
255 
256    {
257 
258       URL  [] urls = {};
259 
260       try
261 
262       {
263 
264          Class   returnType = urls.getClass();
265 
266          Class  [] parameterTypes = {};
267 
268          Method   getURLs = cl.getClass().getMethod("getURLs", parameterTypes);
269 
270          if( returnType.isAssignableFrom(getURLs.getReturnType()) )
271 
272          {
273 
274             Object  [] args = {};
275 
276             urls = (URL  []) getURLs.invoke(cl, args);
277 
278          }
279 
280          if( urls == null || urls.length == 0 )
281 
282          {
283 
284             getURLs = cl.getClass().getMethod("getClasspath", parameterTypes);
285 
286             if( returnType.isAssignableFrom(getURLs.getReturnType()) )
287 
288             {
289 
290                Object  [] args = {};
291 
292                urls = (URL  []) getURLs.invoke(cl, args);
293 
294             }
295 
296          }
297 
298       }
299 
300       catch(Exception   ignore)
301 
302       {
303 
304       }
305 
306       return urls;
307 
308    }
309 
310 
311 
312 }
313 
314 
315 
316
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