1 //
2 // ========================================================================
3 // Copyright (c) 1995-2012 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
20 package org.eclipse.jetty.monitor.triggers;
21
22 import javax.management.MalformedObjectNameException;
23
24
25 /* ------------------------------------------------------------ */
26 /**
27 * EqualToAttrEventTrigger
28 *
29 * Event trigger that polls a value of an MXBean attribute and
30 * checks if it is equal to specified value.
31 */
32 public class EqualToAttrEventTrigger<TYPE extends Comparable<TYPE>> extends AttrEventTrigger<TYPE>
33 {
34 protected final TYPE _value;
35
36 /* ------------------------------------------------------------ */
37 /**
38 * Construct event trigger and specify the MXBean attribute
39 * that will be polled by this event trigger as well as the
40 * target value of the attribute.
41 *
42 * @param objectName object name of an MBean to be polled
43 * @param attributeName name of an MBean attribute to be polled
44 * @param value target value of the attribute
45 *
46 * @throws MalformedObjectNameException
47 * @throws IllegalArgumentException
48 */
49 public EqualToAttrEventTrigger(String objectName, String attributeName, TYPE value)
50 throws MalformedObjectNameException, IllegalArgumentException
51 {
52 super(objectName,attributeName);
53
54 if (value == null)
55 throw new IllegalArgumentException("Value cannot be null");
56
57 _value = value;
58 }
59
60 /* ------------------------------------------------------------ */
61 /**
62 * Compare the value of the MXBean attribute being polling
63 * to check if it is equal to the specified value.
64 */
65 @Override
66 public boolean match(Comparable<TYPE> value)
67 {
68 return (value.compareTo(_value) == 0);
69 }
70
71 /* ------------------------------------------------------------ */
72 /**
73 * Returns the string representation of this event trigger
74 * in the format "name=value".
75 *
76 * @return string representation of the event trigger
77 *
78 * @see java.lang.Object#toString()
79 */
80 public String toString()
81 {
82 StringBuilder result = new StringBuilder();
83
84 result.append(getNameString());
85 result.append("==");
86 result.append(_value);
87
88 return result.toString();
89 }
90 }