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: tdb1 $
 * @version $Id: AlerterManager.java,v 1.6 2001/03/23 00:05:23 tdb1 Exp $
 */
public class AlerterManager extends Thread {

//---FINAL ATTRIBUTES---

    /**
     * The current CVS revision of this class
     */
    public static final String REVISION = "$Revision: 1.6 $";
    
//---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");
        
        _queue = ClientMain._alerterQueue;
        _qID = _queue.getQueue();
        _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 _queue;
    }

//---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();
    
    /**
     * A reference to our Queue
     */
    private Queue _queue;
    
    /**
     * Our queue ID
     */
    private int _qID;
    
    /**
     * 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:	1.7
Committed:	Fri Mar 23 02:30:44 2001 UTC (23 years, 2 months ago) by ajm
Branch:	MAIN
Changes since 1.6:	+15 -4 lines
Log Message:	Javadoc'd the whole bally lot.
#	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			* @author $Author: tdb1 $
20			* @version $Id: AlerterManager.java,v 1.6 2001/03/23 00:05:23 tdb1 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	ajm	1.7	public static final String REVISION = "$Revision: 1.6 $";
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	_queue = ClientMain._alerterQueue;
56			_qID = _queue.getQueue();
57			_logger.write(toString(), Logger.SYSINIT, "Initialising");
58			_logger.write(toString(), Logger.SYSMSG, "Creating alerter pipeline for plugin alerters ...");
59
60	tdb	1.4	// get the config proxy
61			ConfigurationProxy cp = ConfigurationProxy.getInstance();
62
63	ajm	1.1	// get the configuration for this plug-in setup
64	tdb	1.4	String pluginsPackage, pluginsList;
65			try {
66			pluginsPackage = cp.getProperty(_name, "Alerter.PluginsPackage");
67			pluginsList = cp.getProperty(_name, "Alerter.Plugins");
68			} catch(PropertyNotFoundException e) {
69			_logger.write(toString(), Logger.WARNING, "Unable to get required configuration, Alerter's will not be activated: "+e);
70			// setting these will ensure we don't build a pipeline
71			pluginsPackage = "";
72			pluginsList = "";
73			}
74	ajm	1.1
75			StringTokenizer st = new StringTokenizer(pluginsList, ";");
76
77			while(st.hasMoreTokens()) {
78			String className = pluginsPackage + "." + st.nextToken() + _suffix;
79			_logger.write(toString(), Logger.DEBUG, "Attempting to create plugin: "+className);
80
81			// Create an instance of the specified PluginAlerter to include
82			// within the alerterPipe. Add it to the alerterPipeline
83			try {
84			PluginAlerter pa = (PluginAlerter)ClassLoader.getSystemClassLoader().loadClass(className).newInstance();
85			_alerterPipeline.add(pa);
86			_logger.write(toString(), Logger.DEBUG, "Added alerter: "+className+" ("+pa.getDescription()+")");
87			}
88			catch (InstantiationException e){
89			_logger.write(toString(), Logger.ERROR, "Failed to instantiate "+className+" to the plugin alerter pipeline.");
90			_logger.write(toString(), Logger.ERROR, e.getMessage());
91			}
92			catch (Exception e){
93			_logger.write(toString(), Logger.ERROR, "Failed to add "+className+" to the plugin alerter pipeline.");
94			_logger.write(toString(), Logger.ERROR, e.toString());
95			}
96			}
97			_logger.write(toString(), Logger.SYSMSG, "The alerter pipeline has been set up with "+_alerterPipeline.size()+" plugin alerters.");
98			}
99
100			//---PUBLIC METHODS---
101
102			/**
103			* Overrides the {@link java.lang.Object#toString() Object.toString()}
104			* method to provide clean logging (every class should have this).
105			*
106	tdb	1.3	* This uses the uk.org.iscream.util.FormatName class
107	ajm	1.1	* to format the toString()
108			*
109			* @return the name of this class and its CVS revision
110			*/
111			public String toString() {
112			return FormatName.getName(
113			_name,
114			getClass().getName(),
115			REVISION);
116			}
117
118			//---PRIVATE METHODS---
119
120			//---ACCESSOR/MUTATOR METHODS---
121	ajm	1.5
122			/**
123			* Allows alerters to obtain a reference
124			* to the alerting queue so that they can
125			* process any alerts
126			*
127			* @return a reference to the alert queue
128			*/
129			public Queue getQueue() {
130			return _queue;
131			}
132	ajm	1.1
133			//---ATTRIBUTES---
134
135			/**
136			* This is the friendly identifier of the
137			* component this class is running in.
138			* eg, a Filter may be called "filter1",
139			* If this class does not have an owning
140			* component, a name from the configuration
141			* can be placed here. This name could also
142			* be changed to null for utility classes.
143			*/
144			private String _name = ClientMain.NAME;
145
146			/**
147			* This holds a reference to the
148			* system logger that is being used.
149			*/
150			private Logger _logger = ReferenceManager.getInstance().getLogger();
151
152			/**
153			* A reference to the reference manager in use
154			*/
155			private ReferenceManager _refman = ReferenceManager.getInstance();
156
157			/**
158			* A reference to our Queue
159			*/
160			private Queue _queue;
161
162			/**
163			* Our queue ID
164			*/
165			private int _qID;
166
167			/**
168			* file name suffix for plugin alerter classes:
169			*/
170			private final String _suffix = "__Alerter";
171
172			/**
173			* LinkedList for holding the PluginAlerter objects (the pipeline).
174			*/
175			private LinkedList _alerterPipeline = new LinkedList();
176
177			//---STATIC ATTRIBUTES---
178
179			/**
180			* A reference to the single instance of this class
181			*/
182			private static AlerterManager _instance;
183
184			}