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1   /*
2    * Copyright 2000-2001,2004 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.jetspeed.daemon;
18  
19  
20  /***
21  A simple interface to create Daemons within Jetspeed.  These are basically 
22  threads that get work done to facilitate content serving.
23  
24  @author <a href="mailto:burton@apache.org">Kevin A. Burton</a>
25  @version $Id: Daemon.java,v 1.9 2004/02/23 02:48:57 jford Exp $
26  */
27  public interface Daemon extends Runnable {
28  
29      public final static int STATUS_UNKNOWN          = 0;
30      public final static int STATUS_NOT_PROCESSED    = 1;
31      public final static int STATUS_PROCESSED        = 2;
32      public final static int STATUS_PROCESSING       = 3;
33      public final static int STATUS_NOT_STARTED      = 4;
34      public final static int STATUS_STARTED          = 5;
35  
36      /***
37      The result for this daemon is not yet known.
38      */
39      public final static int RESULT_UNKNOWN          = 0;
40  
41      /***
42      A daemon has processed and it was successful
43      */
44      public final static int RESULT_SUCCESS          = 1;
45  
46      /***
47      A daemon has processed but it has failed
48      */
49      public final static int RESULT_FAILED           = 2;
50  
51      /***
52      A daemon is processing so its result is not yet known
53      */
54      public final static int RESULT_PROCESSING       = 3;
55      
56      /***
57      Initialize this daemon providing configuration data.
58      */
59      public void init(DaemonConfig config, DaemonEntry entry);
60  
61      /***
62      Require that Daemons have a getter for the DaemonConfig
63      */
64      public DaemonConfig getDaemonConfig();
65  
66      /***
67      Report on the status of this daemon.  Should be of STATUS_NOT_PROCESSED, 
68      STATUS_PROCESSED, or STATUS_PROCESSING 
69      */
70      public int getStatus();
71  
72      /***
73      Force the status on this Daemon
74      */
75      public void setStatus(int status);
76      
77      /***
78      Get the entry for this daemon.
79      */
80      public DaemonEntry getDaemonEntry();
81  
82      /***
83      <p>
84      Get the result of this daemons processing.  All Daemon implementations 
85      are responsible for defining this.
86      </p>
87      
88      <p>
89      The default for this should be RESULT_UNKNOWN.  This usually means that
90      this daemon has never been called for processing.  
91      </p>
92      */
93      public int getResult();
94  
95      /***
96      Force the result of this Daemon
97      */
98      public void setResult( int result );
99  
100     /***
101     Provided so that a Daemon can provide a message to users.  Null if it has
102     nothing to give to the user.
103     */
104     public String getMessage();
105 }
106