server/client/AlerterManager.java

//---PACKAGE DECLARATION---
package uk.org.iscream.client;

//---IMPORTS---
import uk.org.iscream.componentmanager.*;
import uk.org.iscream.core.*;
import uk.org.iscream.util.*;
import java.util.*;

/**
 * A manager for the Alerters.
 *
 * This class starts by loading all the alerters as specificed in the configuration.
 * These alerters should implement the PluginAlerter interface.
 *
 * This class is then simply a reference point for the Alerters to get hooks on
 * the various parts of the system that they require.
 *
 * @author  $Author: ajm4 $
 * @version $Id: AlerterManager.java,v 1.7 2001/03/23 02:30:44 ajm4 Exp $
 */
public class AlerterManager extends Thread {

//---FINAL ATTRIBUTES---

    /**
     * The current CVS revision of this class
     */
    public static final String REVISION = "$Revision: 1.7 $";
    
//---STATIC METHODS---
    
    /**
     * Return a reference to the single class.
     * Construct it if it does not already exist, otherwise just return the reference.
     */
    public synchronized static AlerterManager getInstance() {
        if (_instance == null){
            _instance = new AlerterManager();
        }
        return _instance;
    }

//---CONSTRUCTORS---
    
    /**
     * Constructs a new AlerterManager.
     * This initialises all the queues and loads
     * all the Alerters that have been specified in the configuration
     */
    private AlerterManager() {
        // set our name
        setName("client.AlerterManager");
        
        _logger.write(toString(), Logger.SYSINIT, "Initialising");
        _logger.write(toString(), Logger.SYSMSG, "Creating alerter pipeline for plugin alerters ...");
        
        // get the config proxy
        ConfigurationProxy cp = ConfigurationProxy.getInstance();
        
        // get the configuration for this plug-in setup
        String pluginsPackage, pluginsList;
        try {
            pluginsPackage = cp.getProperty(_name, "Alerter.PluginsPackage");
            pluginsList = cp.getProperty(_name, "Alerter.Plugins");
        } catch(PropertyNotFoundException e) {
            _logger.write(toString(), Logger.WARNING, "Unable to get required configuration, Alerter's will not be activated: "+e);
            // setting these will ensure we don't build a pipeline
            pluginsPackage = "";
            pluginsList = "";
        }
        
        StringTokenizer st = new StringTokenizer(pluginsList, ";");
        
        while(st.hasMoreTokens()) {
            String className = pluginsPackage + "." + st.nextToken() + _suffix;
            _logger.write(toString(), Logger.DEBUG, "Attempting to create plugin: "+className);
            
            // Create an instance of the specified PluginAlerter to include
            // within the alerterPipe.  Add it to the alerterPipeline
            try {
                PluginAlerter pa = (PluginAlerter)ClassLoader.getSystemClassLoader().loadClass(className).newInstance();
                _alerterPipeline.add(pa);
                _logger.write(toString(), Logger.DEBUG, "Added alerter: "+className+" ("+pa.getDescription()+")");
            }
            catch (InstantiationException e){
                _logger.write(toString(), Logger.ERROR, "Failed to instantiate "+className+" to the plugin alerter pipeline.");
                _logger.write(toString(), Logger.ERROR, e.getMessage());
            }
            catch (Exception e){
                _logger.write(toString(), Logger.ERROR, "Failed to add "+className+" to the plugin alerter pipeline.");
                _logger.write(toString(), Logger.ERROR, e.toString());
            }
        }
        _logger.write(toString(), Logger.SYSMSG, "The alerter pipeline has been set up with "+_alerterPipeline.size()+" plugin alerters.");
    }

//---PUBLIC METHODS---

    /**
     * Overrides the {@link java.lang.Object#toString() Object.toString()}
     * method to provide clean logging (every class should have this).
     *
     * This uses the uk.org.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---

    /**
     * Allows alerters to obtain a reference
     * to the alerting queue so that they can 
     * process any alerts
     *
     * @return a reference to the alert queue
     */
    public Queue getQueue() {
        return ClientMain._alerterQueue;
    }

//---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 = ClientMain.NAME;

    /**
     * This holds a reference to the
     * system logger that is being used.
     */
    private Logger _logger = ReferenceManager.getInstance().getLogger();
    
    /**
     * A reference to the reference manager in use
     */
    private ReferenceManager _refman = ReferenceManager.getInstance();
    
    /**
     * file name suffix for plugin alerter classes:
     */
    private final String _suffix = "__Alerter";
    
    /**
     * LinkedList for holding the PluginAlerter objects (the pipeline).
     */
    private LinkedList _alerterPipeline = new LinkedList();

//---STATIC ATTRIBUTES---

    /**
     * A reference to the single instance of this class
     */
    private static AlerterManager _instance;

}
Revision:	1.8
Committed:	Fri Mar 23 19:12:43 2001 UTC (23 years, 1 month ago) by tdb
Branch:	MAIN
CVS Tags:	PROJECT_COMPLETION
Changes since 1.7:	+4 -16 lines
Log Message:	We were grabbing a queue and then not actually using it. Thus the queue just built up and overflowed. Opps.
#	User	Rev	Content
1	ajm	1.1	//---PACKAGE DECLARATION---
2	tdb	1.3	package uk.org.iscream.client;
3	ajm	1.1
4			//---IMPORTS---
5	tdb	1.3	import uk.org.iscream.componentmanager.*;
6			import uk.org.iscream.core.*;
7			import uk.org.iscream.util.*;
8	ajm	1.1	import java.util.*;
9
10			/**
11	ajm	1.5	* A manager for the Alerters.
12	ajm	1.1	*
13	ajm	1.7	* This class starts by loading all the alerters as specificed in the configuration.
14			* These alerters should implement the PluginAlerter interface.
15			*
16			* This class is then simply a reference point for the Alerters to get hooks on
17			* the various parts of the system that they require.
18			*
19	tdb	1.8	* @author $Author: ajm4 $
20			* @version $Id: AlerterManager.java,v 1.7 2001/03/23 02:30:44 ajm4 Exp $
21	ajm	1.1	*/
22	ajm	1.5	public class AlerterManager extends Thread {
23	ajm	1.1
24			//---FINAL ATTRIBUTES---
25
26			/**
27			* The current CVS revision of this class
28			*/
29	tdb	1.8	public static final String REVISION = "$Revision: 1.7 $";
30	ajm	1.1
31			//---STATIC METHODS---
32
33			/**
34			* Return a reference to the single class.
35			* Construct it if it does not already exist, otherwise just return the reference.
36			*/
37	tdb	1.6	public synchronized static AlerterManager getInstance() {
38	ajm	1.1	if (_instance == null){
39			_instance = new AlerterManager();
40			}
41			return _instance;
42			}
43
44			//---CONSTRUCTORS---
45	ajm	1.7
46			/**
47			* Constructs a new AlerterManager.
48			* This initialises all the queues and loads
49			* all the Alerters that have been specified in the configuration
50			*/
51	tdb	1.2	private AlerterManager() {
52			// set our name
53			setName("client.AlerterManager");
54
55	ajm	1.1	_logger.write(toString(), Logger.SYSINIT, "Initialising");
56			_logger.write(toString(), Logger.SYSMSG, "Creating alerter pipeline for plugin alerters ...");
57
58	tdb	1.4	// get the config proxy
59			ConfigurationProxy cp = ConfigurationProxy.getInstance();
60
61	ajm	1.1	// get the configuration for this plug-in setup
62	tdb	1.4	String pluginsPackage, pluginsList;
63			try {
64			pluginsPackage = cp.getProperty(_name, "Alerter.PluginsPackage");
65			pluginsList = cp.getProperty(_name, "Alerter.Plugins");
66			} catch(PropertyNotFoundException e) {
67			_logger.write(toString(), Logger.WARNING, "Unable to get required configuration, Alerter's will not be activated: "+e);
68			// setting these will ensure we don't build a pipeline
69			pluginsPackage = "";
70			pluginsList = "";
71			}
72	ajm	1.1
73			StringTokenizer st = new StringTokenizer(pluginsList, ";");
74
75			while(st.hasMoreTokens()) {
76			String className = pluginsPackage + "." + st.nextToken() + _suffix;
77			_logger.write(toString(), Logger.DEBUG, "Attempting to create plugin: "+className);
78
79			// Create an instance of the specified PluginAlerter to include
80			// within the alerterPipe. Add it to the alerterPipeline
81			try {
82			PluginAlerter pa = (PluginAlerter)ClassLoader.getSystemClassLoader().loadClass(className).newInstance();
83			_alerterPipeline.add(pa);
84			_logger.write(toString(), Logger.DEBUG, "Added alerter: "+className+" ("+pa.getDescription()+")");
85			}
86			catch (InstantiationException e){
87			_logger.write(toString(), Logger.ERROR, "Failed to instantiate "+className+" to the plugin alerter pipeline.");
88			_logger.write(toString(), Logger.ERROR, e.getMessage());
89			}
90			catch (Exception e){
91			_logger.write(toString(), Logger.ERROR, "Failed to add "+className+" to the plugin alerter pipeline.");
92			_logger.write(toString(), Logger.ERROR, e.toString());
93			}
94			}
95			_logger.write(toString(), Logger.SYSMSG, "The alerter pipeline has been set up with "+_alerterPipeline.size()+" plugin alerters.");
96			}
97
98			//---PUBLIC METHODS---
99
100			/**
101			* Overrides the {@link java.lang.Object#toString() Object.toString()}
102			* method to provide clean logging (every class should have this).
103			*
104	tdb	1.3	* This uses the uk.org.iscream.util.FormatName class
105	ajm	1.1	* to format the toString()
106			*
107			* @return the name of this class and its CVS revision
108			*/
109			public String toString() {
110			return FormatName.getName(
111			_name,
112			getClass().getName(),
113			REVISION);
114			}
115
116			//---PRIVATE METHODS---
117
118			//---ACCESSOR/MUTATOR METHODS---
119	ajm	1.5
120			/**
121			* Allows alerters to obtain a reference
122			* to the alerting queue so that they can
123			* process any alerts
124			*
125			* @return a reference to the alert queue
126			*/
127			public Queue getQueue() {
128	tdb	1.8	return ClientMain._alerterQueue;
129	ajm	1.5	}
130	ajm	1.1
131			//---ATTRIBUTES---
132
133			/**
134			* This is the friendly identifier of the
135			* component this class is running in.
136			* eg, a Filter may be called "filter1",
137			* If this class does not have an owning
138			* component, a name from the configuration
139			* can be placed here. This name could also
140			* be changed to null for utility classes.
141			*/
142			private String _name = ClientMain.NAME;
143
144			/**
145			* This holds a reference to the
146			* system logger that is being used.
147			*/
148			private Logger _logger = ReferenceManager.getInstance().getLogger();
149
150			/**
151			* A reference to the reference manager in use
152			*/
153			private ReferenceManager _refman = ReferenceManager.getInstance();
154
155			/**
156			* file name suffix for plugin alerter classes:
157			*/
158			private final String _suffix = "__Alerter";
159
160			/**
161			* LinkedList for holding the PluginAlerter objects (the pipeline).
162			*/
163			private LinkedList _alerterPipeline = new LinkedList();
164
165			//---STATIC ATTRIBUTES---
166
167			/**
168			* A reference to the single instance of this class
169			*/
170			private static AlerterManager _instance;
171
172			}