server/core/Core.java

//---PACKAGE DECLARATION---
package uk.ac.ukc.iscream.core;

//---IMPORTS---
import uk.ac.ukc.iscream.util.*;
import uk.ac.ukc.iscream.componentmanager.*;

/**
 * The main class for the CORE of the I-Scream system.
 * This class is the component for CORE I-Scream services
 * namely the Logger and the ConfigurationManager.
 * It registers and starts them, at which point it essentially
 * finishs its role and the started services continue to
 * serve requests from the I-Scream system.
 *
 * @author  $Author: tdb1 $
 * @version $Id: Core.java,v 1.22 2001/01/18 23:11:57 tdb1 Exp $
 */
public class Core implements Component {

//---FINAL ATTRIBUTES---

    /**
     * The current CVS revision of this class
     */
    public static final String REVISION = "$Revision: 1.22 $";
    
    /**
     * The friendly name for this component, used by
     * all related classes.
     */
    public static final String NAME = "Core";
    
//---STATIC METHODS---

//---CONSTRUCTORS---

//---PUBLIC METHODS---

    /**
     * This method starts the CORE
     * Currently the args are passed direct to the ORB,
     * so any ORB paramaters could go there.
     *
     */
    public void start() throws ComponentStartException {
        // start and bind each server in turn
        
        // work out which logger to use
        String whichLogger = System.getProperty("uk.ac.ukc.iscream.LoggerClass");
        String loggerPackage = System.getProperty("uk.ac.ukc.iscream.LoggerPackage");
       
        // construct the relevant LoggerImpl
        LoggerImpl loggerImplRef = null;
        try {
            loggerImplRef = (LoggerImpl) ClassLoader.getSystemClassLoader().loadClass(loggerPackage + "." + whichLogger).newInstance();
        } catch (Exception e) {
            // if anything goes wrong we throw a failed start exception
            throw new ComponentStartException("unable to load logging class");
        }

        // setup and bind the LoggerServant
        LoggerServant loggerRef = new LoggerServant(loggerImplRef);
        _refman.bindToOrb(loggerRef, "iscream.Logger");

        // get a reference to the servant as a Logger
        _logger = _refman.getLogger();          
    
        // create the Configurator
        ConfigurationManagerServant configManRef = new ConfigurationManagerServant();
        
        // and advertise it to the naming context
        _refman.bindToOrb(configManRef, "iscream.ConfigurationManager");

        _logger.write(toString(), Logger.SYSINIT, "started");
    }
    
    /**
     * Does a dependency check. Used mainly at startup to
     * see if the required dependencies (components) are up
     * and running.
     *
     * @return a boolean value, true if the depdencies are satisfied
     */
    public boolean depCheck() {
        // the core has no depedencies
        return true;
    }
    
    /**
     * 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.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---

//---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 = Core.NAME;

    /**
     * This holds a reference to the
     * system logger that is being used.
     */
    private Logger _logger;

    /**
     * A reference to the reference manager in use
     */
    private ReferenceManager _refman = ReferenceManager.getInstance();
    
//---STATIC ATTRIBUTES---

}
Revision:	1.23
Committed:	Wed Mar 14 01:34:26 2001 UTC (23 years, 2 months ago) by tdb
Branch:	MAIN
Changes since 1.22:	+14 -2 lines
Log Message:	New dependency checking. The old method was to attempt to start a Component, and if it failed, it probably had a depdency problem. The approach now is to ask the Component to perform a dependency check first, then if this suceeds, have a go at actually starting it up. The actual dependency check is a bit neater and more precise than before, and should be much more fool proof. The order the components are specified in the default.properties file is now irrelevant, although the "correct" order would certainly increase booting time.
#	User	Rev	Content
1	tdb	1.13	//---PACKAGE DECLARATION---
2	ajm	1.16	package uk.ac.ukc.iscream.core;
3	tdb	1.13
4			//---IMPORTS---
5	ajm	1.18	import uk.ac.ukc.iscream.util.*;
6	tdb	1.21	import uk.ac.ukc.iscream.componentmanager.*;
7	tdb	1.13
8			/**
9			* The main class for the CORE of the I-Scream system.
10	ajm	1.18	* This class is the component for CORE I-Scream services
11			* namely the Logger and the ConfigurationManager.
12			* It registers and starts them, at which point it essentially
13	tdb	1.13	* finishs its role and the started services continue to
14			* serve requests from the I-Scream system.
15			*
16	tdb	1.22	* @author $Author: tdb1 $
17	tdb	1.23	* @version $Id: Core.java,v 1.22 2001/01/18 23:11:57 tdb1 Exp $
18	tdb	1.13	*/
19	tdb	1.22	public class Core implements Component {
20	tdb	1.13
21			//---FINAL ATTRIBUTES---
22
23			/**
24			* The current CVS revision of this class
25			*/
26	tdb	1.23	public static final String REVISION = "$Revision: 1.22 $";
27	tdb	1.13
28			/**
29	ajm	1.20	* The friendly name for this component, used by
30	ajm	1.18	* all related classes.
31	tdb	1.13	*/
32	ajm	1.19	public static final String NAME = "Core";
33	tdb	1.13
34			//---STATIC METHODS---
35
36	ajm	1.17	//---CONSTRUCTORS---
37
38			//---PUBLIC METHODS---
39
40	tdb	1.13	/**
41	ajm	1.18	* This method starts the CORE
42	tdb	1.13	* Currently the args are passed direct to the ORB,
43			* so any ORB paramaters could go there.
44			*
45			*/
46	ajm	1.18	public void start() throws ComponentStartException {
47	ajm	1.17	// start and bind each server in turn
48
49			// work out which logger to use
50			String whichLogger = System.getProperty("uk.ac.ukc.iscream.LoggerClass");
51			String loggerPackage = System.getProperty("uk.ac.ukc.iscream.LoggerPackage");
52
53			// construct the relevant LoggerImpl
54			LoggerImpl loggerImplRef = null;
55	tdb	1.13	try {
56	ajm	1.17	loggerImplRef = (LoggerImpl) ClassLoader.getSystemClassLoader().loadClass(loggerPackage + "." + whichLogger).newInstance();
57	tdb	1.13	} catch (Exception e) {
58	ajm	1.18	// if anything goes wrong we throw a failed start exception
59			throw new ComponentStartException("unable to load logging class");
60	tdb	1.13	}
61	ajm	1.19
62	ajm	1.17	// setup and bind the LoggerServant
63			LoggerServant loggerRef = new LoggerServant(loggerImplRef);
64			_refman.bindToOrb(loggerRef, "iscream.Logger");
65	tdb	1.13
66	ajm	1.17	// get a reference to the servant as a Logger
67			_logger = _refman.getLogger();
68	tdb	1.13
69	ajm	1.17	// create the Configurator
70	ajm	1.18	ConfigurationManagerServant configManRef = new ConfigurationManagerServant();
71	ajm	1.17
72			// and advertise it to the naming context
73			_refman.bindToOrb(configManRef, "iscream.ConfigurationManager");
74
75	ajm	1.18	_logger.write(toString(), Logger.SYSINIT, "started");
76	tdb	1.23	}
77
78			/**
79			* Does a dependency check. Used mainly at startup to
80			* see if the required dependencies (components) are up
81			* and running.
82			*
83			* @return a boolean value, true if the depdencies are satisfied
84			*/
85			public boolean depCheck() {
86			// the core has no depedencies
87			return true;
88	ajm	1.18	}
89
90			/**
91			* Overrides the {@link java.lang.Object#toString() Object.toString()}
92			* method to provide clean logging (every class should have this).
93			*
94			* This uses the uk.ac.ukc.iscream.util.NameFormat class
95			* to format the toString()
96			*
97			* @return the name of this class and its CVS revision
98			*/
99			public String toString() {
100			return FormatName.getName(
101			_name,
102	ajm	1.20	getClass().getName(),
103	ajm	1.18	REVISION);
104	tdb	1.13	}
105
106			//---PRIVATE METHODS---
107
108			//---ACCESSOR/MUTATOR METHODS---
109
110			//---ATTRIBUTES---
111	ajm	1.18
112			/**
113			* This is the friendly identifier of the
114			* component this class is running in.
115			* eg, a Filter may be called "filter1",
116			* If this class does not have an owning
117			* component, a name from the configuration
118			* can be placed here. This name could also
119			* be changed to null for utility classes.
120			*/
121			private String _name = Core.NAME;
122
123			/**
124			* This holds a reference to the
125			* system logger that is being used.
126			*/
127			private Logger _logger;
128
129			/**
130			* A reference to the reference manager in use
131			*/
132			private ReferenceManager _refman = ReferenceManager.getInstance();
133	tdb	1.13
134			//---STATIC ATTRIBUTES---
135
136			}