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 1.4 2001/02/28 19:02:22 tdb1 Exp $
 */
class QueueMonitor extends Thread {

//---FINAL ATTRIBUTES---

    /**
     * The current CVS revision of this class
     */
    public static final String REVISION = "$Revision: 1.4 $";
    
//---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();
            // get a hash of our Queue (for identification)
            String hashCode = String.valueOf(_sourceQueue.hashCode());
            // create some XML
            String date = new Long(System.currentTimeMillis()/((long) 1000)).toString();
            String xml = "<packet type=\"queueStat\" date=\""+date+"\" name=\""+_srcName+"\" hashCode=\""+hashCode+"\">" + 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:	Thu Mar 1 03:04:28 2001 UTC (23 years, 1 month ago) by tdb
Branch:	MAIN
CVS Tags:	PROJECT_COMPLETION, HEAD
Changes since 1.2:	+5 -3 lines
Log Message:	Brought inline with main source tree.
#	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 1.4 2001/02/28 19:02:22 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: 1.4 $";
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	// get a hash of our Queue (for identification)
59	String hashCode = String.valueOf(_sourceQueue.hashCode());
60	// create some XML
61	String date = new Long(System.currentTimeMillis()/((long) 1000)).toString();
62	String xml = "<packet type=\"queueStat\" date=\""+date+"\" name=\""+_srcName+"\" hashCode=\""+hashCode+"\">" + status + "</packet>";
63	// write XML to destination Queue
64	_destQueue.add(xml);
65	}
66	}
67
68	/**
69	* Shuts down this QueueMonitor
70	*/
71	public void shutdown() {
72	// this will stop the main loop
73	_run = false;
74	// create some XML
75	String date = new Long(System.currentTimeMillis()/((long) 1000)).toString();
76	String xml = "<packet type=\"queueStat\" date=\""+date+"\" name=\""+_srcName+"\" shutdown=\"true\"></packet>";
77	// write XML to destination Queue
78	_destQueue.add(xml);
79	}
80
81	/**
82	* Overrides the {@link java.lang.Object#toString() Object.toString()}
83	* method to provide clean logging (every class should have this).
84	*
85	* This uses the uk.ac.ukc.iscream.util.FormatName class
86	* to format the toString()
87	*
88	* @return the name of this class and its CVS revision
89	*/
90	public String toString() {
91	return FormatName.getName(
92	_name,
93	getClass().getName(),
94	REVISION);
95	}
96
97	//---PRIVATE METHODS---
98
99	//---ACCESSOR/MUTATOR METHODS---
100
101	//---ATTRIBUTES---
102
103	/**
104	* This is the friendly identifier of the
105	* component this class is running in.
106	* eg, a Filter may be called "filter1",
107	* If this class does not have an owning
108	* component, a name from the configuration
109	* can be placed here. This name could also
110	* be changed to null for utility classes.
111	*/
112	private String _name = null;
113
114	/**
115	* The Queue we're monitoring.
116	*/
117	private Queue _sourceQueue;
118
119	/**
120	* The Queue we'll output results to.
121	*/
122	private Queue _destQueue;
123
124	/**
125	* The interval at which we'll check the
126	* sourceQueue status.
127	*/
128	private long _interval;
129
130	/**
131	* The name to identify the source Queue
132	*/
133	private String _srcName;
134
135	/**
136	* Allows us to stop the main loop cleanly.
137	*/
138	private boolean _run;
139
140	//---STATIC ATTRIBUTES---
141
142	}