server/Queue/QueueMonitor.java

//---PACKAGE DECLARATION---
//package uk.ac.ukc.iscream.util;

//---IMPORTS---
//import uk.ac.ukc.iscream.util.*;

/**
 * This class monitors a given Queue at regular intervals,
 * reporting back to a Queue with XML - this could be the
 * same Queue being monitored.
 *
 * @author  $Author: tdb1 $
 * @version $Id: QueueMonitor.java,v 1.1 2001/02/12 02:20:23 tdb1 Exp $
 */
class QueueMonitor extends Thread {

//---FINAL ATTRIBUTES---

    /**
     * The current CVS revision of this class
     */
    public static final String REVISION = "$Revision: 1.1 $";
    
//---STATIC METHODS---

//---CONSTRUCTORS---
    
    /**
     * Construct a new QueueMonitor.
     *
     * @param sourceQueue The Queue to monitor
     * @param destQueue The Queue to monitor to
     * @param interval The interval, in milliseconds, at which to sample
     * @param name A name to identify the source Queue with
     */
    public QueueMonitor (Queue sourceQueue, Queue destQueue, long interval, String name) {
        _sourceQueue = sourceQueue;
        _destQueue = destQueue;
        _interval = interval;
        _srcName = name;
    }

//---PUBLIC METHODS---
    
    /**
     * Loops continuosly polling our source Queue at
     * the given interval, and then logging the results
     * in the destination Queue.
     */
    public void run() {
        _run = true;
        // so we can stop this thread...
        while(_run) {
            // first sleep for our interval
            try { Thread.sleep(_interval); } catch(Exception e) {}
            // check the Queue
            String status = _sourceQueue.xmlStatus();
            // create some XML
            String date = new Long(System.currentTimeMillis()/((long) 1000)).toString();
            String xml = "<packet type=\"queueStat\" date=\""+date+"\" name=\""+_srcName+"\">" + status + "</packet>";
            // write XML to destination Queue
            _destQueue.add(xml);
        }
    }
    
    /**
     * Shuts down this QueueMonitor
     */
    public void shutdown() {
        // this will stop the main loop
        _run = false;
    }
    
    /**
     * Overrides the {@link java.lang.Object#toString() Object.toString()}
     * method to provide clean logging (every class should have this).
     *
     * This uses the uk.ac.ukc.iscream.util.FormatName class
     * to format the toString()
     *
     * @return the name of this class and its CVS revision
     */
    public String toString() {
        return FormatName.getName(
            _name,
            getClass().getName(),
            REVISION);
    }

//---PRIVATE METHODS---

//---ACCESSOR/MUTATOR METHODS---

//---ATTRIBUTES---

    /**
     * This is the friendly identifier of the
     * component this class is running in.
     * eg, a Filter may be called "filter1",
     * If this class does not have an owning
     * component,  a name from the configuration
     * can be placed here.  This name could also
     * be changed to null for utility classes.
     */
    private String _name = null;
    
    /**
     * The Queue we're monitoring.
     */
    private Queue _sourceQueue;
    
    /**
     * The Queue we'll output results to.
     */
    private Queue _destQueue;
    
    /**
     * The interval at which we'll check the
     * sourceQueue status.
     */
    private long _interval;
    
    /**
     * The name to identify the source Queue
     */
    private String _srcName;
    
    /**
     * Allows us to stop the main loop cleanly.
     */
    private boolean _run;
    
//---STATIC ATTRIBUTES---

}
Revision:	1.1
Committed:	Mon Feb 12 02:27:56 2001 UTC (23 years, 9 months ago) by tdb
Branch:	MAIN
Log Message:	Brought in line with changes in main tree. Now supports Queue monitoring in XML format, to another Queue (or the same Queue).
#	User	Rev	Content
1	tdb	1.1	//---PACKAGE DECLARATION---
2			//package uk.ac.ukc.iscream.util;
3
4			//---IMPORTS---
5			//import uk.ac.ukc.iscream.util.*;
6
7			/**
8			* This class monitors a given Queue at regular intervals,
9			* reporting back to a Queue with XML - this could be the
10			* same Queue being monitored.
11			*
12			* @author $Author: tdb1 $
13			* @version $Id: QueueMonitor.java,v 1.1 2001/02/12 02:20:23 tdb1 Exp $
14			*/
15			class QueueMonitor extends Thread {
16
17			//---FINAL ATTRIBUTES---
18
19			/**
20			* The current CVS revision of this class
21			*/
22			public static final String REVISION = "$Revision: 1.1 $";
23
24			//---STATIC METHODS---
25
26			//---CONSTRUCTORS---
27
28			/**
29			* Construct a new QueueMonitor.
30			*
31			* @param sourceQueue The Queue to monitor
32			* @param destQueue The Queue to monitor to
33			* @param interval The interval, in milliseconds, at which to sample
34			* @param name A name to identify the source Queue with
35			*/
36			public QueueMonitor (Queue sourceQueue, Queue destQueue, long interval, String name) {
37			_sourceQueue = sourceQueue;
38			_destQueue = destQueue;
39			_interval = interval;
40			_srcName = name;
41			}
42
43			//---PUBLIC METHODS---
44
45			/**
46			* Loops continuosly polling our source Queue at
47			* the given interval, and then logging the results
48			* in the destination Queue.
49			*/
50			public void run() {
51			_run = true;
52			// so we can stop this thread...
53			while(_run) {
54			// first sleep for our interval
55			try { Thread.sleep(_interval); } catch(Exception e) {}
56			// check the Queue
57			String status = _sourceQueue.xmlStatus();
58			// create some XML
59			String date = new Long(System.currentTimeMillis()/((long) 1000)).toString();
60			String xml = "<packet type=\"queueStat\" date=\""+date+"\" name=\""+_srcName+"\">" + status + "</packet>";
61			// write XML to destination Queue
62			_destQueue.add(xml);
63			}
64			}
65
66			/**
67			* Shuts down this QueueMonitor
68			*/
69			public void shutdown() {
70			// this will stop the main loop
71			_run = false;
72			}
73
74			/**
75			* Overrides the {@link java.lang.Object#toString() Object.toString()}
76			* method to provide clean logging (every class should have this).
77			*
78			* This uses the uk.ac.ukc.iscream.util.FormatName class
79			* to format the toString()
80			*
81			* @return the name of this class and its CVS revision
82			*/
83			public String toString() {
84			return FormatName.getName(
85			_name,
86			getClass().getName(),
87			REVISION);
88			}
89
90			//---PRIVATE METHODS---
91
92			//---ACCESSOR/MUTATOR METHODS---
93
94			//---ATTRIBUTES---
95
96			/**
97			* This is the friendly identifier of the
98			* component this class is running in.
99			* eg, a Filter may be called "filter1",
100			* If this class does not have an owning
101			* component, a name from the configuration
102			* can be placed here. This name could also
103			* be changed to null for utility classes.
104			*/
105			private String _name = null;
106
107			/**
108			* The Queue we're monitoring.
109			*/
110			private Queue _sourceQueue;
111
112			/**
113			* The Queue we'll output results to.
114			*/
115			private Queue _destQueue;
116
117			/**
118			* The interval at which we'll check the
119			* sourceQueue status.
120			*/
121			private long _interval;
122
123			/**
124			* The name to identify the source Queue
125			*/
126			private String _srcName;
127
128			/**
129			* Allows us to stop the main loop cleanly.
130			*/
131			private boolean _run;
132
133			//---STATIC ATTRIBUTES---
134
135			}