server/client/AlerterManager.java

/* 
 * i-scream central monitoring system
 * http://www.i-scream.org.uk
 * Copyright (C) 2000-2002 i-scream
 * 
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 * 
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 */

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

//---IMPORTS---
import uk.org.iscream.cms.server.componentmanager.*;
import uk.org.iscream.cms.server.core.*;
import uk.org.iscream.cms.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: tdb $
 * @version $Id: AlerterManager.java,v 1.11 2002/05/21 16:47:16 tdb Exp $
 */
public class AlerterManager extends Thread {

//---FINAL ATTRIBUTES---

    /**
     * The current CVS revision of this class
     */
    public static final String REVISION = "$Revision: 1.11 $";
    
//---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.cms.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:	1.12
Committed:	Wed Feb 5 16:43:44 2003 UTC (21 years, 3 months ago) by tdb
Branch:	MAIN
Changes since 1.11:	+4 -4 lines
Log Message:	Changed the server to use the external util package. Quite a minor change, but does affect a lot of files.
#	User	Rev	Content
1	tdb	1.10	/*
2			* i-scream central monitoring system
3	tdb	1.11	* http://www.i-scream.org.uk
4	tdb	1.10	* Copyright (C) 2000-2002 i-scream
5			*
6			* This program is free software; you can redistribute it and/or
7			* modify it under the terms of the GNU General Public License
8			* as published by the Free Software Foundation; either version 2
9			* of the License, or (at your option) any later version.
10			*
11			* This program is distributed in the hope that it will be useful,
12			* but WITHOUT ANY WARRANTY; without even the implied warranty of
13			* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14			* GNU General Public License for more details.
15			*
16			* You should have received a copy of the GNU General Public License
17			* along with this program; if not, write to the Free Software
18			* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
19			*/
20
21	ajm	1.1	//---PACKAGE DECLARATION---
22	tdb	1.9	package uk.org.iscream.cms.server.client;
23	ajm	1.1
24			//---IMPORTS---
25	tdb	1.9	import uk.org.iscream.cms.server.componentmanager.*;
26			import uk.org.iscream.cms.server.core.*;
27	tdb	1.12	import uk.org.iscream.cms.util.*;
28	ajm	1.1	import java.util.*;
29
30			/**
31	ajm	1.5	* A manager for the Alerters.
32	ajm	1.1	*
33	ajm	1.7	* This class starts by loading all the alerters as specificed in the configuration.
34			* These alerters should implement the PluginAlerter interface.
35			*
36			* This class is then simply a reference point for the Alerters to get hooks on
37			* the various parts of the system that they require.
38			*
39	tdb	1.10	* @author $Author: tdb $
40	tdb	1.12	* @version $Id: AlerterManager.java,v 1.11 2002/05/21 16:47:16 tdb Exp $
41	ajm	1.1	*/
42	ajm	1.5	public class AlerterManager extends Thread {
43	ajm	1.1
44			//---FINAL ATTRIBUTES---
45
46			/**
47			* The current CVS revision of this class
48			*/
49	tdb	1.12	public static final String REVISION = "$Revision: 1.11 $";
50	ajm	1.1
51			//---STATIC METHODS---
52
53			/**
54			* Return a reference to the single class.
55			* Construct it if it does not already exist, otherwise just return the reference.
56			*/
57	tdb	1.6	public synchronized static AlerterManager getInstance() {
58	ajm	1.1	if (_instance == null){
59			_instance = new AlerterManager();
60			}
61			return _instance;
62			}
63
64			//---CONSTRUCTORS---
65	ajm	1.7
66			/**
67			* Constructs a new AlerterManager.
68			* This initialises all the queues and loads
69			* all the Alerters that have been specified in the configuration
70			*/
71	tdb	1.2	private AlerterManager() {
72			// set our name
73			setName("client.AlerterManager");
74
75	ajm	1.1	_logger.write(toString(), Logger.SYSINIT, "Initialising");
76			_logger.write(toString(), Logger.SYSMSG, "Creating alerter pipeline for plugin alerters ...");
77
78	tdb	1.4	// get the config proxy
79			ConfigurationProxy cp = ConfigurationProxy.getInstance();
80
81	ajm	1.1	// get the configuration for this plug-in setup
82	tdb	1.4	String pluginsPackage, pluginsList;
83			try {
84			pluginsPackage = cp.getProperty(_name, "Alerter.PluginsPackage");
85			pluginsList = cp.getProperty(_name, "Alerter.Plugins");
86			} catch(PropertyNotFoundException e) {
87			_logger.write(toString(), Logger.WARNING, "Unable to get required configuration, Alerter's will not be activated: "+e);
88			// setting these will ensure we don't build a pipeline
89			pluginsPackage = "";
90			pluginsList = "";
91			}
92	ajm	1.1
93			StringTokenizer st = new StringTokenizer(pluginsList, ";");
94
95			while(st.hasMoreTokens()) {
96			String className = pluginsPackage + "." + st.nextToken() + _suffix;
97			_logger.write(toString(), Logger.DEBUG, "Attempting to create plugin: "+className);
98
99			// Create an instance of the specified PluginAlerter to include
100			// within the alerterPipe. Add it to the alerterPipeline
101			try {
102			PluginAlerter pa = (PluginAlerter)ClassLoader.getSystemClassLoader().loadClass(className).newInstance();
103			_alerterPipeline.add(pa);
104			_logger.write(toString(), Logger.DEBUG, "Added alerter: "+className+" ("+pa.getDescription()+")");
105			}
106			catch (InstantiationException e){
107			_logger.write(toString(), Logger.ERROR, "Failed to instantiate "+className+" to the plugin alerter pipeline.");
108			_logger.write(toString(), Logger.ERROR, e.getMessage());
109			}
110			catch (Exception e){
111			_logger.write(toString(), Logger.ERROR, "Failed to add "+className+" to the plugin alerter pipeline.");
112			_logger.write(toString(), Logger.ERROR, e.toString());
113			}
114			}
115			_logger.write(toString(), Logger.SYSMSG, "The alerter pipeline has been set up with "+_alerterPipeline.size()+" plugin alerters.");
116			}
117
118			//---PUBLIC METHODS---
119
120			/**
121			* Overrides the {@link java.lang.Object#toString() Object.toString()}
122			* method to provide clean logging (every class should have this).
123			*
124	tdb	1.12	* This uses the uk.org.iscream.cms.util.FormatName class
125	ajm	1.1	* to format the toString()
126			*
127			* @return the name of this class and its CVS revision
128			*/
129			public String toString() {
130			return FormatName.getName(
131			_name,
132			getClass().getName(),
133			REVISION);
134			}
135
136			//---PRIVATE METHODS---
137
138			//---ACCESSOR/MUTATOR METHODS---
139	ajm	1.5
140			/**
141			* Allows alerters to obtain a reference
142			* to the alerting queue so that they can
143			* process any alerts
144			*
145			* @return a reference to the alert queue
146			*/
147			public Queue getQueue() {
148	tdb	1.8	return ClientMain._alerterQueue;
149	ajm	1.5	}
150	ajm	1.1
151			//---ATTRIBUTES---
152
153			/**
154			* This is the friendly identifier of the
155			* component this class is running in.
156			* eg, a Filter may be called "filter1",
157			* If this class does not have an owning
158			* component, a name from the configuration
159			* can be placed here. This name could also
160			* be changed to null for utility classes.
161			*/
162			private String _name = ClientMain.NAME;
163
164			/**
165			* This holds a reference to the
166			* system logger that is being used.
167			*/
168			private Logger _logger = ReferenceManager.getInstance().getLogger();
169
170			/**
171			* A reference to the reference manager in use
172			*/
173			private ReferenceManager _refman = ReferenceManager.getInstance();
174
175			/**
176			* file name suffix for plugin alerter classes:
177			*/
178			private final String _suffix = "__Alerter";
179
180			/**
181			* LinkedList for holding the PluginAlerter objects (the pipeline).
182			*/
183			private LinkedList _alerterPipeline = new LinkedList();
184
185			//---STATIC ATTRIBUTES---
186
187			/**
188			* A reference to the single instance of this class
189			*/
190			private static AlerterManager _instance;
191
192			}