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1   /*
2    * Copyright 2002,2004 The Apache Software Foundation.
3    *
4    * Licensed under the Apache License, Version 2.0 (the "License");
5    * you may not use this file except in compliance with the License.
6    * You may obtain a copy of the License at
7    *
8    *      http://www.apache.org/licenses/LICENSE-2.0
9    *
10   * Unless required by applicable law or agreed to in writing, software
11   * distributed under the License is distributed on an "AS IS" BASIS,
12   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13   * See the License for the specific language governing permissions and
14   * limitations under the License.
15   */
16  
17  package org.apache.commons.jelly.tags.threads;
18  
19  import org.apache.commons.jelly.JellyTagException;
20  import org.apache.commons.jelly.TagSupport;
21  import org.apache.commons.jelly.XMLOutput;
22  
23  /***
24   * Base class for tags that will "use" mutexes.
25   *
26   * @author <a href="mailto:jason@jhorman.org">Jason Horman</a>
27   */
28  
29  public abstract class UseMutexTag extends TagSupport {
30      /*** The mutex to use in some way. */
31      private Object mutex = null;
32  
33      /*** Calls useMutex after checking to make sure that <i>setMutex</i> was called */
34      public void doTag(XMLOutput output) throws JellyTagException {
35          // either use the set thread or search for a parent thread to use
36          if (mutex == null) {
37              throw new JellyTagException("no mutex set");
38          }
39  
40          useMutex(mutex, output);
41      }
42  
43      /*** Implement this method to do something with the mutex */
44      protected abstract void useMutex(Object mutex, XMLOutput output) throws JellyTagException;
45  
46      /*** Get the mutex */
47      public Object getMutex() {
48          return mutex;
49      }
50  
51      /*** Set the mutex. Any object can be used as a mutex. */
52      public void setMutex(Object mutex) {
53          this.mutex = mutex;
54      }
55  }