server/componentmanager/ReferenceManager.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.componentmanager;

//---IMPORTS---
import org.omg.CORBA.ORB;
import org.omg.CosNaming.*;
import org.omg.PortableServer.*;
import uk.org.iscream.cms.server.core.*;
import uk.org.iscream.cms.util.*;

/**
 * This class returns references for global system objects.
 * This class is used to create and return references to objects
 * that are required throughout the system.  Most of which
 * are CORBA based.  It also manages the ORB for the component.
 *
 * It is a singleton object with a static method to obtain a
 * reference to it.  This removes the need for passing
 * references to all the objects it contains throughout 
 * a component.
 *
 * @author  $Author: tdb $
 * @version $Id: ReferenceManager.java,v 1.19 2003/02/05 16:43:46 tdb Exp $
 */
public class ReferenceManager {

//---FINAL ATTRIBUTES---
   
    /**
     * The current CVS revision of this class
     */
    public final String REVISION = "$Revision: 1.19 $";
    
//---STATIC METHODS---

    /**
     * This returns a reference to the single instance of the
     * ReferenceManager.
     *
     * This creates the single instance of the ReferenceManager
     * if it does not exist by calling the private constructor.
     *
     * @return a reference to the ReferenceManager
     */
    public synchronized static ReferenceManager getInstance() {
        if (_instance == null) {
            _instance = new ReferenceManager();
        }
        return _instance;
    }

//---CONSTRUCTORS---

    /**
     * This is a private constructor
     * This ensures that the system performs according to a Singleton design pattern
     */
    private ReferenceManager() {
        _orb = ORB.init(new String[] {}, null);
    }

//---PUBLIC METHODS---

    /**
     * Obtains a CORBA reference through the naming service
     * for the named object.
     * Calls the dieWithError() if any exceptions happen!
     *
     * @param name the name of the CORBA object to resolve
     *
     * @return a reference to the object
     */
    public org.omg.CORBA.Object getCORBARef(String name) {
        org.omg.CORBA.Object objRef = null;
        try {
            objRef = getNS().resolve(getNS().to_name(name));
        } catch (org.omg.CosNaming.NamingContextPackage.CannotProceed e) {
            dieWithError("\nCRITICAL:Naming Service Cannot Proceed - when resolving reference to " + name + "!\n" + 
                              "         Please check with your CORBA naming service provider.");
        } catch (org.omg.CosNaming.NamingContextPackage.InvalidName e) {
            dieWithError("\nCRITICAL:Invalid Name - when resolving reference to " + name + "!\n" + 
                              "         Please check with your CORBA naming service provider.");
        } catch (org.omg.CosNaming.NamingContextPackage.NotFound e) {
            recoverWithError("\nCRITICAL:Not Found - when resolving reference to " + name + "!\n" + 
                              "         Please check that this component is running.");
        }
        return objRef;
    }

    /** 
     * Binds a given servant with the given name
     * to the naming service.
     * Calls the dieWithError() if any exceptions happen!
     *
     * @param objRef a reverence to the servant object
     * @param name the name to bind to the naming service with
     */
    public void bindToOrb(org.omg.PortableServer.Servant objRef, String name) {
        try {
            getNS().bind(getNS().to_name(name), getRootPOA().servant_to_reference(objRef));
        } catch (org.omg.PortableServer.POAPackage.WrongPolicy e) {
            dieWithError("\nCRITICAL:Wrong POA Policy - when binding " + name + "!\n" + 
                              "         This indicates an error with your ORB.");
        } catch (org.omg.PortableServer.POAPackage.ServantNotActive e) {
            dieWithError("\nCRITICAL:ServantNotActive - when binding " + name + "!\n" + 
                              "         This indicates an error with your ORB.");
        } catch (org.omg.CosNaming.NamingContextPackage.InvalidName e) {
            dieWithError("\nCRITICAL:Invalid Name - when binding " + name + "!\n" + 
                              "         Please check with your CORBA naming service provider.");
        } catch (org.omg.CosNaming.NamingContextPackage.CannotProceed e) {
            dieWithError("\nCRITICAL:Naming Service Cannot Proceed - when binding " + name + "!\n" + 
                              "         Please check with your CORBA naming service provider.");
        } catch (org.omg.CosNaming.NamingContextPackage.NotFound e) {
            recoverWithError("\nCRITICAL:Naming Service Not Found - when binding " + name + "!\n" + 
                              "         Please check with your CORBA naming service provider.");
        } catch (org.omg.CosNaming.NamingContextPackage.AlreadyBound e) {
            dieWithError("\nCRITICAL:Already Bound - when binding " + name + "!\n" + 
                              "         Another component with this name is already running.");
        }
    }
    
    /**
     * Activates the POA
     * Calls the dieWithError() if any exceptions happen!
     */
    public void activatePOA() {
        try {
            getRootPOA().the_POAManager().activate();
        } catch (org.omg.PortableServer.POAManagerPackage.AdapterInactive e) {
            dieWithError("\nCRITICAL:POA Set Inactive - when trying to activate POA!\n" + 
                              "         This indicates an error with your ORB.");
        }
    }
    
    /**
     * 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.NameFormat 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---

    /**
     * If there are any CORBA errors this method is called with the 
     * error message.
     *
     * The exception this throws is generic to CORBA communication
     * problems, this is a Runtime exception and is typically only
     * explicitly caught in the ComponentManager for the current VM
     * The ComponentManager can then decide what course of action to 
     * take.
     *
     * Also, if it can, it will log the message with the logger.
     *
     * @param message the error message to die with
     */
    private void recoverWithError(String message) throws ComponentCORBAException {
        if (_logger != null) {
            _logger.write(toString(), Logger.WARNING, "component CORBA error - " + message);
        }
        throw new ComponentCORBAException(message);
    }


    /**
     * If there are any CORBA errors this method is called with the 
     * error message.
     *
     * Currently this prints the error, on the local err stream.  Will
     * print to the logger if one is available.
     *
     * ANY CALLS TO THIS METHOD CAUSE
     * THE SYSTEM TO EXIT WITH A NON
     * ZERO CODE!
     *
     * @param message the error message to die with
     */
    private void dieWithError(String message) {
        System.err.println(message);
        if (_logger != null) {
            _logger.write(toString(), Logger.FATAL, message);
        }
        System.exit(1);
    }


//---ACCESSOR/MUTATOR METHODS---

    /**
     * Returns a reference to the ORB
     *
     * @return the reference this class holds
     */
    public ORB getORB() {
        return _orb;
    }

    /**
     * Returns a reference to the Root POA
     * Calls the dieWithError() if any exceptions happen!
     *
     * @return the reference this class holds
     */
    public POA getRootPOA() {
        if (_rootPOA == null) {
            org.omg.CORBA.Object objRef = null;
            try {
                objRef = getORB().resolve_initial_references("RootPOA");
            } catch (org.omg.CORBA.ORBPackage.InvalidName e) {
                dieWithError("\nCRITICAL:Unable to resolve reference to the RootPOA!\n" + 
                                  "         This indicates an error with your ORB.");
            }
            _rootPOA = POAHelper.narrow(objRef);
        }
        return _rootPOA;
    }
    
    /**
     * Returns a reference to the Naming Service
     * Calls the dieWithError() if any exceptions happen!
     *
     * @return the reference this class holds
     */
    public NamingContextExt getNS() {
        if (_ns == null) {
            org.omg.CORBA.Object objRef = null;
            try {
                objRef = getORB().resolve_initial_references("NameService");
            } catch (org.omg.CORBA.ORBPackage.InvalidName e) {
                dieWithError("\nCRITICAL:Unable to resolve reference to the Naming Service!\n" +
                                  "         Please check with your CORBA naming service provider.");
            } catch (java.lang.NullPointerException e) {
                dieWithError("\nCRITICAL:Unable to resolve reference to the Naming Service!\n" +
                             "         Please check with your CORBA naming service provider.");
            }
            _ns = NamingContextExtHelper.narrow(objRef);
        }
        // check we managed to talk to the naming service
        if (_ns == null) {
            dieWithError("\nCRITICAL:Unable to resolve reference to the Naming Service!\n" +
                              "         Please check with your CORBA naming service provider.");
        }
        return _ns;
    }
    
    /**
     * Returns a reference to the configuration manager
     * Calls the dieWithError() if any exceptions happen!
     *
     * @return the reference this class holds
     */
    public ConfigurationManager getCM() {
        if (_cm == null) {
            _cm = ConfigurationManagerHelper.narrow(getCORBARef("iscream.ConfigurationManager"));
        }
        // check we managed to talk to the configuration manager
        if (_cm == null) {
            dieWithError("\nCRITICAL:Unable to resolve reference to the Configuration Manager!\n" +
                              "         Please check with your CORBA naming service provider.");
        }
        return _cm;
    }

    /**
     * Returns a reference to the logger
     * This will throw a Error if there is an error
     *
     * @return the reference this class holds
     */
    public Logger getLogger() {
        if (_logger == null) {
            _logger = LoggerHelper.narrow(getCORBARef("iscream.Logger"));
        }
        return _logger;
    }
    
//---ATTRIBUTES---
    
    /**
     * The ORB
     */
    private ORB _orb;
    
    /**
     * The Naming Service
     */
    private NamingContextExt _ns;
    
    /**
     * The Root POA
     */
    private POA _rootPOA;

    /**
     * The configuration manager
     */
    private ConfigurationManager _cm;

    /**
     * The logger
     */
    private Logger _logger;
    
    /**
     * 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;

//---STATIC ATTRIBUTES---
    
    /**
     * A reference to the single instance of this class
     */
    private static ReferenceManager _instance = null; 
}
Revision:	1.20
Committed:	Mon Jul 14 16:05:54 2003 UTC (20 years, 10 months ago) by ajm
Branch:	MAIN
Changes since 1.19:	+5 -2 lines
Log Message:	Added a NullPointerException check Niklas Saers, it now errors with a vaguely sensible error of: "Unable to resolve reference to the Naming Service!"
#	User	Rev	Content
1	tdb	1.17	/*
2			* i-scream central monitoring system
3	tdb	1.18	* http://www.i-scream.org.uk
4	tdb	1.17	* 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	1.16	package uk.org.iscream.cms.server.componentmanager;
23	ajm	1.1
24			//---IMPORTS---
25			import org.omg.CORBA.ORB;
26			import org.omg.CosNaming.*;
27			import org.omg.PortableServer.*;
28	tdb	1.16	import uk.org.iscream.cms.server.core.*;
29	tdb	1.19	import uk.org.iscream.cms.util.*;
30	ajm	1.1
31			/**
32			* This class returns references for global system objects.
33			* This class is used to create and return references to objects
34			* that are required throughout the system. Most of which
35	ajm	1.2	* are CORBA based. It also manages the ORB for the component.
36	ajm	1.1	*
37			* It is a singleton object with a static method to obtain a
38			* reference to it. This removes the need for passing
39			* references to all the objects it contains throughout
40			* a component.
41			*
42	tdb	1.17	* @author $Author: tdb $
43	ajm	1.20	* @version $Id: ReferenceManager.java,v 1.19 2003/02/05 16:43:46 tdb Exp $
44	ajm	1.1	*/
45			public class ReferenceManager {
46
47			//---FINAL ATTRIBUTES---
48
49			/**
50			* The current CVS revision of this class
51			*/
52	ajm	1.20	public final String REVISION = "$Revision: 1.19 $";
53	ajm	1.1
54			//---STATIC METHODS---
55
56			/**
57			* This returns a reference to the single instance of the
58			* ReferenceManager.
59			*
60	ajm	1.6	* This creates the single instance of the ReferenceManager
61			* if it does not exist by calling the private constructor.
62			*
63	ajm	1.1	* @return a reference to the ReferenceManager
64			*/
65	tdb	1.15	public synchronized static ReferenceManager getInstance() {
66	ajm	1.1	if (_instance == null) {
67	ajm	1.6	_instance = new ReferenceManager();
68	ajm	1.1	}
69			return _instance;
70			}
71
72			//---CONSTRUCTORS---
73
74			/**
75			* This is a private constructor
76			* This ensures that the system performs according to a Singleton design pattern
77	ajm	1.6	*/
78			private ReferenceManager() {
79			_orb = ORB.init(new String[] {}, null);
80			}
81	ajm	1.1
82			//---PUBLIC METHODS---
83
84			/**
85	ajm	1.2	* Obtains a CORBA reference through the naming service
86			* for the named object.
87	ajm	1.7	* Calls the dieWithError() if any exceptions happen!
88	ajm	1.2	*
89			* @param name the name of the CORBA object to resolve
90			*
91			* @return a reference to the object
92			*/
93			public org.omg.CORBA.Object getCORBARef(String name) {
94			org.omg.CORBA.Object objRef = null;
95			try {
96			objRef = getNS().resolve(getNS().to_name(name));
97			} catch (org.omg.CosNaming.NamingContextPackage.CannotProceed e) {
98	ajm	1.6	dieWithError("\nCRITICAL:Naming Service Cannot Proceed - when resolving reference to " + name + "!\n" +
99	ajm	1.5	" Please check with your CORBA naming service provider.");
100	ajm	1.2	} catch (org.omg.CosNaming.NamingContextPackage.InvalidName e) {
101	ajm	1.6	dieWithError("\nCRITICAL:Invalid Name - when resolving reference to " + name + "!\n" +
102	ajm	1.5	" Please check with your CORBA naming service provider.");
103	ajm	1.2	} catch (org.omg.CosNaming.NamingContextPackage.NotFound e) {
104	ajm	1.12	recoverWithError("\nCRITICAL:Not Found - when resolving reference to " + name + "!\n" +
105	ajm	1.5	" Please check that this component is running.");
106	ajm	1.2	}
107			return objRef;
108			}
109
110			/**
111			* Binds a given servant with the given name
112			* to the naming service.
113	ajm	1.7	* Calls the dieWithError() if any exceptions happen!
114	ajm	1.2	*
115			* @param objRef a reverence to the servant object
116			* @param name the name to bind to the naming service with
117			*/
118			public void bindToOrb(org.omg.PortableServer.Servant objRef, String name) {
119			try {
120			getNS().bind(getNS().to_name(name), getRootPOA().servant_to_reference(objRef));
121			} catch (org.omg.PortableServer.POAPackage.WrongPolicy e) {
122	ajm	1.6	dieWithError("\nCRITICAL:Wrong POA Policy - when binding " + name + "!\n" +
123	ajm	1.5	" This indicates an error with your ORB.");
124	ajm	1.2	} catch (org.omg.PortableServer.POAPackage.ServantNotActive e) {
125	ajm	1.6	dieWithError("\nCRITICAL:ServantNotActive - when binding " + name + "!\n" +
126	ajm	1.5	" This indicates an error with your ORB.");
127	ajm	1.2	} catch (org.omg.CosNaming.NamingContextPackage.InvalidName e) {
128	ajm	1.6	dieWithError("\nCRITICAL:Invalid Name - when binding " + name + "!\n" +
129	ajm	1.5	" Please check with your CORBA naming service provider.");
130	ajm	1.2	} catch (org.omg.CosNaming.NamingContextPackage.CannotProceed e) {
131	ajm	1.6	dieWithError("\nCRITICAL:Naming Service Cannot Proceed - when binding " + name + "!\n" +
132	ajm	1.5	" Please check with your CORBA naming service provider.");
133	ajm	1.2	} catch (org.omg.CosNaming.NamingContextPackage.NotFound e) {
134	ajm	1.12	recoverWithError("\nCRITICAL:Naming Service Not Found - when binding " + name + "!\n" +
135	ajm	1.5	" Please check with your CORBA naming service provider.");
136	ajm	1.2	} catch (org.omg.CosNaming.NamingContextPackage.AlreadyBound e) {
137	ajm	1.6	dieWithError("\nCRITICAL:Already Bound - when binding " + name + "!\n" +
138	ajm	1.5	" Another component with this name is already running.");
139	ajm	1.2	}
140			}
141
142			/**
143			* Activates the POA
144	ajm	1.7	* Calls the dieWithError() if any exceptions happen!
145	ajm	1.2	*/
146			public void activatePOA() {
147			try {
148			getRootPOA().the_POAManager().activate();
149			} catch (org.omg.PortableServer.POAManagerPackage.AdapterInactive e) {
150	ajm	1.6	dieWithError("\nCRITICAL:POA Set Inactive - when trying to activate POA!\n" +
151	ajm	1.5	" This indicates an error with your ORB.");
152	ajm	1.2	}
153			}
154
155			/**
156	ajm	1.1	* Overrides the {@link java.lang.Object#toString() Object.toString()}
157			* method to provide clean logging (every class should have this).
158			*
159	tdb	1.19	* This uses the uk.org.iscream.cms.util.NameFormat class
160	ajm	1.6	* to format the toString()
161			*
162	ajm	1.1	* @return the name of this class and its CVS revision
163			*/
164			public String toString() {
165	ajm	1.6	return FormatName.getName(
166	ajm	1.7	_name,
167			getClass().getName(),
168	ajm	1.6	REVISION);
169	ajm	1.1	}
170
171			//---PRIVATE METHODS---
172
173	ajm	1.6	/**
174			* If there are any CORBA errors this method is called with the
175			* error message.
176			*
177	ajm	1.11	* The exception this throws is generic to CORBA communication
178			* problems, this is a Runtime exception and is typically only
179			* explicitly caught in the ComponentManager for the current VM
180			* The ComponentManager can then decide what course of action to
181			* take.
182	ajm	1.6	*
183	ajm	1.11	* Also, if it can, it will log the message with the logger.
184	ajm	1.6	*
185			* @param message the error message to die with
186			*/
187	ajm	1.12	private void recoverWithError(String message) throws ComponentCORBAException {
188	ajm	1.6	if (_logger != null) {
189	ajm	1.11	_logger.write(toString(), Logger.WARNING, "component CORBA error - " + message);
190	ajm	1.6	}
191	ajm	1.11	throw new ComponentCORBAException(message);
192	ajm	1.6	}
193	ajm	1.12
194
195			/**
196			* If there are any CORBA errors this method is called with the
197			* error message.
198			*
199			* Currently this prints the error, on the local err stream. Will
200			* print to the logger if one is available.
201			*
202			* ANY CALLS TO THIS METHOD CAUSE
203			* THE SYSTEM TO EXIT WITH A NON
204			* ZERO CODE!
205			*
206			* @param message the error message to die with
207			*/
208			private void dieWithError(String message) {
209			System.err.println(message);
210			if (_logger != null) {
211			_logger.write(toString(), Logger.FATAL, message);
212			}
213			System.exit(1);
214			}
215
216
217	ajm	1.6
218	ajm	1.1	//---ACCESSOR/MUTATOR METHODS---
219
220			/**
221			* Returns a reference to the ORB
222			*
223			* @return the reference this class holds
224			*/
225			public ORB getORB() {
226			return _orb;
227			}
228
229			/**
230			* Returns a reference to the Root POA
231	ajm	1.7	* Calls the dieWithError() if any exceptions happen!
232	ajm	1.1	*
233			* @return the reference this class holds
234			*/
235			public POA getRootPOA() {
236			if (_rootPOA == null) {
237			org.omg.CORBA.Object objRef = null;
238			try {
239			objRef = getORB().resolve_initial_references("RootPOA");
240			} catch (org.omg.CORBA.ORBPackage.InvalidName e) {
241	ajm	1.6	dieWithError("\nCRITICAL:Unable to resolve reference to the RootPOA!\n" +
242	ajm	1.5	" This indicates an error with your ORB.");
243	ajm	1.1	}
244			_rootPOA = POAHelper.narrow(objRef);
245			}
246			return _rootPOA;
247			}
248
249			/**
250			* Returns a reference to the Naming Service
251	ajm	1.7	* Calls the dieWithError() if any exceptions happen!
252	ajm	1.1	*
253			* @return the reference this class holds
254			*/
255			public NamingContextExt getNS() {
256			if (_ns == null) {
257			org.omg.CORBA.Object objRef = null;
258			try {
259			objRef = getORB().resolve_initial_references("NameService");
260			} catch (org.omg.CORBA.ORBPackage.InvalidName e) {
261	ajm	1.6	dieWithError("\nCRITICAL:Unable to resolve reference to the Naming Service!\n" +
262	ajm	1.5	" Please check with your CORBA naming service provider.");
263	ajm	1.20	} catch (java.lang.NullPointerException e) {
264			dieWithError("\nCRITICAL:Unable to resolve reference to the Naming Service!\n" +
265			" Please check with your CORBA naming service provider.");
266	ajm	1.1	}
267			_ns = NamingContextExtHelper.narrow(objRef);
268			}
269	ajm	1.5	// check we managed to talk to the naming service
270			if (_ns == null) {
271	ajm	1.6	dieWithError("\nCRITICAL:Unable to resolve reference to the Naming Service!\n" +
272	ajm	1.5	" Please check with your CORBA naming service provider.");
273			}
274	ajm	1.1	return _ns;
275			}
276
277			/**
278			* Returns a reference to the configuration manager
279	ajm	1.7	* Calls the dieWithError() if any exceptions happen!
280	ajm	1.1	*
281			* @return the reference this class holds
282			*/
283			public ConfigurationManager getCM() {
284			if (_cm == null) {
285	ajm	1.2	_cm = ConfigurationManagerHelper.narrow(getCORBARef("iscream.ConfigurationManager"));
286	ajm	1.1	}
287	ajm	1.5	// check we managed to talk to the configuration manager
288			if (_cm == null) {
289	ajm	1.6	dieWithError("\nCRITICAL:Unable to resolve reference to the Configuration Manager!\n" +
290	ajm	1.5	" Please check with your CORBA naming service provider.");
291			}
292	ajm	1.1	return _cm;
293			}
294
295			/**
296			* Returns a reference to the logger
297	ajm	1.5	* This will throw a Error if there is an error
298	ajm	1.1	*
299			* @return the reference this class holds
300			*/
301			public Logger getLogger() {
302			if (_logger == null) {
303	ajm	1.2	_logger = LoggerHelper.narrow(getCORBARef("iscream.Logger"));
304	ajm	1.1	}
305			return _logger;
306	ajm	1.4	}
307	ajm	1.1
308			//---ATTRIBUTES---
309
310			/**
311			* The ORB
312			*/
313			private ORB _orb;
314
315			/**
316			* The Naming Service
317			*/
318			private NamingContextExt _ns;
319
320			/**
321			* The Root POA
322			*/
323			private POA _rootPOA;
324
325			/**
326			* The configuration manager
327			*/
328			private ConfigurationManager _cm;
329
330			/**
331			* The logger
332			*/
333			private Logger _logger;
334
335			/**
336	ajm	1.7	* This is the friendly identifier of the
337			* component this class is running in.
338			* eg, a Filter may be called "filter1",
339			* If this class does not have an owning
340			* component, a name from the configuration
341			* can be placed here. This name could also
342			* be changed to null for utility classes.
343	ajm	1.1	*/
344	ajm	1.7	private String _name = null;
345	ajm	1.1
346			//---STATIC ATTRIBUTES---
347
348			/**
349			* A reference to the single instance of this class
350			*/
351	ajm	1.14	private static ReferenceManager _instance = null;
352	ajm	1.1	}