cms/util/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 1.2 2001/02/12 02:27:17 tdb1 Exp $
 */
class QueueMonitor extends Thread {

//---FINAL ATTRIBUTES---

    /**
     * The current CVS revision of this class
     */
    public static final String REVISION = "$Revision: 1.2 $";
    
//---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;
        // create some XML
        String date = new Long(System.currentTimeMillis()/((long) 1000)).toString();
        String xml = "<packet type=\"queueStat\" date=\""+date+"\" name=\""+_srcName+"\" shutdown=\"true\"></packet>";
        // write XML to destination Queue
        _destQueue.add(xml);
    }
    
    /**
     * 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:	1.3
Committed:	Mon Feb 26 00:36:10 2001 UTC (23 years, 2 months ago) by tdb
Branch:	MAIN
Changes since 1.2:	+7 -2 lines
Log Message:	Just sending out a packet to say we're no longer monitoring a Queue. Could be useful in the Client if it's displaying queueStat information.
#	Content
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 1.2 2001/02/12 02:27:17 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: 1.2 $";
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	// create some XML
73	String date = new Long(System.currentTimeMillis()/((long) 1000)).toString();
74	String xml = "<packet type=\"queueStat\" date=\""+date+"\" name=\""+_srcName+"\" shutdown=\"true\"></packet>";
75	// write XML to destination Queue
76	_destQueue.add(xml);
77	}
78
79	/**
80	* Overrides the {@link java.lang.Object#toString() Object.toString()}
81	* method to provide clean logging (every class should have this).
82	*
83	* This uses the uk.ac.ukc.iscream.util.FormatName class
84	* to format the toString()
85	*
86	* @return the name of this class and its CVS revision
87	*/
88	public String toString() {
89	return FormatName.getName(
90	_name,
91	getClass().getName(),
92	REVISION);
93	}
94
95	//---PRIVATE METHODS---
96
97	//---ACCESSOR/MUTATOR METHODS---
98
99	//---ATTRIBUTES---
100
101	/**
102	* This is the friendly identifier of the
103	* component this class is running in.
104	* eg, a Filter may be called "filter1",
105	* If this class does not have an owning
106	* component, a name from the configuration
107	* can be placed here. This name could also
108	* be changed to null for utility classes.
109	*/
110	private String _name = null;
111
112	/**
113	* The Queue we're monitoring.
114	*/
115	private Queue _sourceQueue;
116
117	/**
118	* The Queue we'll output results to.
119	*/
120	private Queue _destQueue;
121
122	/**
123	* The interval at which we'll check the
124	* sourceQueue status.
125	*/
126	private long _interval;
127
128	/**
129	* The name to identify the source Queue
130	*/
131	private String _srcName;
132
133	/**
134	* Allows us to stop the main loop cleanly.
135	*/
136	private boolean _run;
137
138	//---STATIC ATTRIBUTES---
139
140	}