core/loggers/ScreenLogger.java

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

//---IMPORTS---
import uk.ac.ukc.iscream.util.*;
import uk.ac.ukc.iscream.core.*;
import java.util.Date;
import java.text.DateFormat;
import java.util.Locale;

/**
 * The ScreenLogger is an implementation of the LoggerImpl defined
 * in the associated interface. It's only purpose is to simply print
 * all the logging information it receives to the screen.
 *
 * @author  $Author: ajm4 $
 * @version $Id: ScreenLogger.java,v 1.2 2000/11/29 21:27:25 ajm4 Exp $
 */
public class ScreenLogger implements LoggerImpl {

//---FINAL ATTRIBUTES---

    /**
     * The current CVS revision of this class
     */
    public final String REVISION = "$Revision: 1.2 $";
    
//---STATIC METHODS---

//---CONSTRUCTORS---

    /**
     * Creates a new ScreenLoggerServant.
     */
    public ScreenLogger() {
        _verbosityLevel = Integer.parseInt(System.getProperty("uk.ac.ukc.iscream.Verbosity"));
        write(toString(), Logger.SYSINIT, "started");
        write(toString(), Logger.SYSMSG, "using verbosity " + _verbosityLevel);
    }

//---PUBLIC METHODS---

    /**
     * The write() method takes a message, formats it using the
     * formatLogLine() method, and then outputs it to the screen
     * using System.out.println(). The source is usually the
     * calling object, referenced by `this'. The method has been
     * made synchronized to avoid it being called by two different
     * objects and the output ending up merged on the screen.
     * 
     * @param source A string representation of the calling object.
     * @param verbosity the verbosity of this message
     * @param message The text to be logged.
     */   
    public synchronized void write(String source, int verbosity, String message) {
        if (verbosity <= _verbosityLevel) {
            String line = formatLogLine(source, message);
            System.out.println(line);
        }
    }
       
    /**
     * 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.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---

    /**
     * This method generates a nicely formatted line for the log,
     * including the date/time and the source of the message. The date
     * and time are formatted using the DateFormat class, and the source
     * class is formatted using the toString() method found in every
     * source file. This is then prepended to the message and returned.
     * 
     * @param source A string representation of the calling object.
     * @param message The message to be logged.
     * @return The string to be written to the log.
     */
    private String formatLogLine(String source, String message){
        String date = DateFormat.getDateTimeInstance(DateFormat.SHORT, DateFormat.MEDIUM).format(new Date());
        return "[" + date + "] " + source + ": " + message;
    }

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

//---ATTRIBUTES---

    /**
     * The verbosity level of this instance
     */
    private int _verbosityLevel;
    
    /**
     * 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;
    
//---STATIC ATTRIBUTES---
    
}
Revision:	1.3
Committed:	Tue Dec 12 18:28:19 2000 UTC (23 years, 5 months ago) by ajm
Branch:	MAIN
Changes since 1.2:	+56 -39 lines
Log Message:	brought inline with new standards
#	Content
1	//---PACKAGE DECLARATION---
2	package uk.ac.ukc.iscream.core.loggers;
3
4	//---IMPORTS---
5	import uk.ac.ukc.iscream.util.*;
6	import uk.ac.ukc.iscream.core.*;
7	import java.util.Date;
8	import java.text.DateFormat;
9	import java.util.Locale;
10
11	/**
12	* The ScreenLogger is an implementation of the LoggerImpl defined
13	* in the associated interface. It's only purpose is to simply print
14	* all the logging information it receives to the screen.
15	*
16	* @author $Author: ajm4 $
17	* @version $Id: ScreenLogger.java,v 1.2 2000/11/29 21:27:25 ajm4 Exp $
18	*/
19	public class ScreenLogger implements LoggerImpl {
20
21	//---FINAL ATTRIBUTES---
22
23	/**
24	* The current CVS revision of this class
25	*/
26	public final String REVISION = "$Revision: 1.2 $";
27
28	//---STATIC METHODS---
29
30	//---CONSTRUCTORS---
31
32	/**
33	* Creates a new ScreenLoggerServant.
34	*/
35	public ScreenLogger() {
36	_verbosityLevel = Integer.parseInt(System.getProperty("uk.ac.ukc.iscream.Verbosity"));
37	write(toString(), Logger.SYSINIT, "started");
38	write(toString(), Logger.SYSMSG, "using verbosity " + _verbosityLevel);
39	}
40
41	//---PUBLIC METHODS---
42
43	/**
44	* The write() method takes a message, formats it using the
45	* formatLogLine() method, and then outputs it to the screen
46	* using System.out.println(). The source is usually the
47	* calling object, referenced by `this'. The method has been
48	* made synchronized to avoid it being called by two different
49	* objects and the output ending up merged on the screen.
50	*
51	* @param source A string representation of the calling object.
52	* @param verbosity the verbosity of this message
53	* @param message The text to be logged.
54	*/
55	public synchronized void write(String source, int verbosity, String message) {
56	if (verbosity <= _verbosityLevel) {
57	String line = formatLogLine(source, message);
58	System.out.println(line);
59	}
60	}
61
62	/**
63	* Overrides the {@link java.lang.Object#toString() Object.toString()}
64	* method to provide clean logging (every class should have this).
65	*
66	* This uses the uk.ac.ukc.iscream.util.FormatName class
67	* to format the toString()
68	*
69	* @return the name of this class and its CVS revision
70	*/
71	public String toString() {
72	return FormatName.getName(
73	_name,
74	getClass().getName(),
75	REVISION);
76	}
77
78	//---PRIVATE METHODS---
79
80	/**
81	* This method generates a nicely formatted line for the log,
82	* including the date/time and the source of the message. The date
83	* and time are formatted using the DateFormat class, and the source
84	* class is formatted using the toString() method found in every
85	* source file. This is then prepended to the message and returned.
86	*
87	* @param source A string representation of the calling object.
88	* @param message The message to be logged.
89	* @return The string to be written to the log.
90	*/
91	private String formatLogLine(String source, String message){
92	String date = DateFormat.getDateTimeInstance(DateFormat.SHORT, DateFormat.MEDIUM).format(new Date());
93	return "[" + date + "] " + source + ": " + message;
94	}
95
96	//---ACCESSOR/MUTATOR METHODS---
97
98	//---ATTRIBUTES---
99
100	/**
101	* The verbosity level of this instance
102	*/
103	private int _verbosityLevel;
104
105	/**
106	* This is the friendly identifier of the
107	* component this class is running in.
108	* eg, a Filter may be called "filter1",
109	* If this class does not have an owning
110	* component, a name from the configuration
111	* can be placed here. This name could also
112	* be changed to null for utility classes.
113	*/
114	private String _name = Core.NAME;
115
116	//---STATIC ATTRIBUTES---
117
118	}