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1   //
2   //  ========================================================================
3   //  Copyright (c) 1995-2015 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.monitor.jmx;
20  
21  import static java.util.UUID.randomUUID;
22  
23  import java.security.InvalidParameterException;
24  
25  /* ------------------------------------------------------------ */
26  /**
27   * MonitorAction
28   * 
29   * Abstract base class for all MonitorAction implementations. 
30   * Receives notification when an associated EventTrigger is matched.
31   */
32  public abstract class MonitorAction
33      extends NotifierGroup
34  {
35      public static final int DEFAULT_POLL_INTERVAL = 5000;
36      
37      private final String _id;
38      private final EventTrigger _trigger;
39      private final EventNotifier _notifier;
40      private final long _pollInterval;
41      private final long _pollDelay;
42  
43      /* ------------------------------------------------------------ */
44      /**
45       * Creates a new monitor action 
46       * 
47       * @param trigger event trigger to be associated with this action
48       * @throws InvalidParameterException
49       */
50      public MonitorAction(EventTrigger trigger)
51          throws InvalidParameterException
52      {
53          this(trigger, null, 0, 0);
54      }
55      
56      
57      /* ------------------------------------------------------------ */
58      /**
59       * Creates a new monitor action 
60       * 
61       * @param trigger event trigger to be associated with this action
62       * @param notifier event notifier to be associated with this action
63       * @throws InvalidParameterException
64       */
65      public MonitorAction(EventTrigger trigger, EventNotifier notifier)
66          throws InvalidParameterException
67      {
68          this(trigger, notifier, 0);
69      }
70      
71      /* ------------------------------------------------------------ */
72      /**
73       * Creates a new monitor action 
74       * 
75       * @param trigger event trigger to be associated with this action
76       * @param notifier event notifier to be associated with this action
77       * @param pollInterval interval for polling of the JMX server
78       * @throws InvalidParameterException
79       */
80      public MonitorAction(EventTrigger trigger, EventNotifier notifier, long pollInterval)
81          throws InvalidParameterException
82      {
83          this(trigger, notifier, pollInterval, 0);
84      }
85  
86      /* ------------------------------------------------------------ */
87      /**
88       * Creates a new monitor action 
89       * 
90       * @param trigger event trigger to be associated with this action
91       * @param notifier event notifier to be associated with this action
92       * @param pollInterval interval for polling of the JMX server
93       * @param pollDelay delay before starting to poll the JMX server
94       * @throws InvalidParameterException
95       */
96      public MonitorAction(EventTrigger trigger, EventNotifier notifier, long pollInterval, long pollDelay)
97          throws InvalidParameterException
98      {
99          if (trigger == null)
100             throw new InvalidParameterException("Trigger cannot be null");
101         
102         _id = randomUUID().toString();
103         _trigger = trigger;
104         _notifier = notifier;
105         _pollInterval = pollInterval > 0 ? pollInterval : DEFAULT_POLL_INTERVAL;
106         _pollDelay = pollDelay > 0 ? pollDelay : _pollInterval;
107     }
108     
109     /* ------------------------------------------------------------ */
110     /**
111      * Retrieve the identification string of the monitor action
112      * 
113      * @return unique identification string
114      */
115 
116     public final String getID()
117     {
118         return _id;
119     }
120     
121    
122     /* ------------------------------------------------------------ */
123     /**
124      * Retrieve the event trigger of the monitor action
125      * 
126      * @return associated event trigger
127      */
128     public EventTrigger getTrigger()
129     {
130         return _trigger;
131     }
132     
133     /* ------------------------------------------------------------ */
134     /**
135      * Retrieve the poll interval
136      * 
137      * @return interval value (in milliseconds)
138      */
139     public long getPollInterval()
140     {
141         return _pollInterval;
142     }
143     
144 
145     /* ------------------------------------------------------------ */
146     /** Retrieve the poll delay
147      * @return delay value (in milliseconds)
148      */
149     public long getPollDelay()
150     {
151         return _pollDelay;
152     }
153 
154     /* ------------------------------------------------------------ */
155     /**
156      * This method will be called when event trigger associated
157      * with this monitor action matches its conditions.
158      * 
159      * @param timestamp time stamp of the event
160      */
161     public final void doExecute(long timestamp)
162     {
163         EventState<?> state =_trigger.getState(timestamp);
164         if (_notifier != null)
165             _notifier.notify(_trigger, state, timestamp);
166         execute(_trigger, state, timestamp);
167     }
168 
169     /* ------------------------------------------------------------ */
170     /**
171      * This method will be called to allow subclass to execute
172      * the desired action in response to the event.
173      * 
174      * @param trigger event trigger associated with this monitor action
175      * @param state event state associated with current invocation of event trigger
176      * @param timestamp time stamp of the current invocation of event trigger
177      */
178     public abstract void execute(EventTrigger trigger, EventState<?> state, long timestamp);
179  }