core/loggers/FileLogger.java

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

//---IMPORTS---
import uk.org.iscream.cms.server.util.*;
import uk.org.iscream.cms.server.core.*;
import java.util.Date;
import java.text.DateFormat;
import java.util.Locale;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileWriter;
import java.io.IOException;

/**
 * The FileLogger is an implementation of the LoggerImpl defined
 * in the associated interface. It provides quite extensive features to allow
 * logging ot a text file.
 *
 * @author  $Author: tdb1 $
 * @version $Id: FileLogger.java,v 1.8 2001/03/14 23:25:29 tdb1 Exp $
 */
public class FileLogger implements LoggerImpl {

//---FINAL ATTRIBUTES---

    /**
     * The current CVS revision of this class
     */
    public final String REVISION = "$Revision: 1.8 $";
    
//---STATIC METHODS---

//---CONSTRUCTORS---

        /**
         * Creates a new FileLogger.
         *
         * The constructor checks that writing will be ok, then sets up the
         * writer. It makes use of the fileCheck() method found later on to
         * ensure writing will be ok, and throws an IOException if there is
         * a problem. Errors at this stage cannot be logged because the
         * logging mechanism has not be setup completely, so any problems
         * are printed to the screen in the same format used for logging.
         * 
         * @throws IOException if there is a problem with the file check.
         */
    public FileLogger() throws IOException{
        filename = System.getProperty("uk.org.iscream.cms.server.LoggerClass.FileLogger.filename");
                // Perform file check to make sure writing is ok
        if(!fileCheck()){
                        // Have to system.out.println errors because logging mechanism failed !
                        System.out.println(FormatName.formatLogLine(this.toString(), Logger.FATAL, "File check failed, construction terminated"));
            throw new IOException("File check failed, unable to create FileLog");
        }
        try{
                        // Setup the writer
            writer = new BufferedWriter(new FileWriter(filename, true));
                        // File is now open
                        open = true;
        }
        catch(IOException e){
            System.out.println(FormatName.formatLogLine(this.toString(), Logger.FATAL, "Attempt to setup writer failed - " + e.getMessage()));
        }
                // Put an initial line into the log
        write(toString(), Logger.SYSINIT, "started");
    }

//---PUBLIC METHODS---
    
    /**
         * The write() method takes a line of text, pre-formatted
         * and outputs it using a method defined by the actual
         * implementation. The verbosity is given in case the
         * implementation wishes to utilise it in the layout -
         * eg. a different colour or font.
         * 
         * This instance writes the line to a file.
         *
         * @param line A line of formatted text to be logged
         * @param verbosity the verbosity of this message
         */  
    public synchronized void write(String line, int verbosity) {
                // Check to make sure file is open
                if(open){
                        // Produce a nicely formatted line for the logfile
                        try{
                                // We have to synchronize here due to problems with two write()'s being called before a newLine()
                                synchronized(writer){
                                        // Attempt to write the line
                                        writer.write(line);
                                        // Best to use newLine() as it will use the correct platform encoding
                                        writer.newLine();
                                }
                                // Make sure the line is written immeidiately
                                writer.flush();
                        }
                        catch(IOException e){
                                // We'd best log the error
                                System.out.println(FormatName.formatLogLine(this.toString(), Logger.FATAL, "Writing to logfile failed - " + e.getMessage()));
                                // As it's an IOException we should suspend logging
                                open = false;
                }
                }
                else{
                        // If file is not open we should print this to the screen
                        System.out.println(FormatName.formatLogLine(this.toString(), Logger.FATAL, "Write failed - file not open"));
                }
    }
 
        /**
         * The clear() method erases the contents of the logfile. It does
         * this in a very clumsy way - by closing the writer and opening a
         * new one which is set not to append. This results in the logfile
         * being overwritten, which effectively erases it.
         */
    public void clear(){
                // Check file is open
                if(open){
                        write(toString(), Logger.SYSMSG, "Attempting to clear logfile");
                        try{
                                // Close appending writer
                                open = false;
                                writer.close();
                                // Open a non-appending writer
                                writer = new BufferedWriter(new FileWriter(filename));
                                open = true;
                        }
                        catch(IOException e){
                                // We'd best log the error
                                write(toString(), Logger.ERROR, "Attempt to clear logfile failed - "+e.getMessage());
                                // As it's an IOException we should suspend logging
                                open = false;
                        }
                }
                else{
                        // If file is not open we should print this to the screen
                        System.out.println(FormatName.formatLogLine(this.toString(), Logger.FATAL, "Clearing failed - file not open"));
                }
    }
    
        /**
         * The close() method closes the logfile and no more data can be written.
         * If writing is attempted after close() has been called an error will be
         * generated. The open() method can be used to reopen or open a new file.
         */
    public void close(){
                // Check to see if a file is open
                if(open){
                        write(toString(), Logger.SYSMSG, "Attempting to terminate logging");
                        try{
                                open = false;
                        writer.close();         
                        }
                        catch(IOException e){
                                write(toString(), Logger.ERROR, "Attempt to close logfile failed - " + e.getMessage());
                                // As it's an IOException we should suspend logging
                                open = false;
                        }
                }
                else{
                        // If file is not open we should print this to the screen
                        System.out.println(FormatName.formatLogLine(this.toString(), Logger.FATAL, "Close failed - file not open"));
                }
    }
    
        /**
         * The open() method opens a new file after the close() method has
         * been called on the FileLog. This enables the user to easily change
         * the file to which the log is being written. An error is generated
         * if a file is already open.
         * 
         * @param filename The new file to write to.
         * @throws IOException if the file cannot be written to.
         */
        public void open(String filename) throws IOException{
                // Check to see if a file is open
                if(open){
                        // If file is already open then we should log that this went wrong
                        write(this.toString(), Logger.WARNING, "Open failed - a file is already open");
                }
                else{
                        this.filename = filename;
                        if(!fileCheck()) {
                                // Have to system.out.println errors because logging mechanism failed !
                                System.out.println(FormatName.formatLogLine(this.toString(), Logger.FATAL, "File check failed, construction terminated"));
                                throw new IOException("File check failed, unable to create FileLog");
                        }
                        try{
                                // Setup the writer
                                writer = new BufferedWriter(new FileWriter(filename, true));
                                // File is now open
                                open = true;
                        }
                        catch(IOException e){
                            System.out.println(FormatName.formatLogLine(this.toString(), Logger.FATAL, "Attempt to open writer failed - " + e.getMessage()));
                        }
                }
        }

        /**
         * The suspend() method halts writing to the file by setting the open
         * boolean to false, and thus blocking the write() method. A line is
         * written to the logfile beforehand to note that writing has been
         * suspended.
         */
        public void suspend(){
                // Check to see if a file is open
                if(open){
                        // Make a note of the fact that writing has been suspended
                        write(toString(), Logger.SYSMSG, "Writing suspended");
                        // Make sure writing not permitted
                        open=false;
                }
                else{
                        // If file is not open we should print this to the screen
                        System.out.println(FormatName.formatLogLine(this.toString(), Logger.FATAL, "Suspend failed - file not open"));
                }
        }
        
        /**
         * The resume() method resumes writing to the file by setting the open
         * boolean to true. A line is written to the logfile to signify this
         * event occuring.
         */
        public void resume(){
                // Check to see if a file is open
                if(open){
                        // If file is open we should print this to the screen
                        System.out.println(FormatName.formatLogLine(this.toString(), Logger.FATAL, "Resume failed - file open"));
                }
                else{
                        // Permit writing again
                        open=true;
                        // Make a note of the fact that writing has been resumed
                        write(toString(), Logger.SYSMSG, "Writing resumed");
                }
        }
    
    /**
     * 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.server.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---

        /**
         * The fileCheck() method is used to ensure that writing is ok. It
         * performs so basic checks to make sure that if the file exists
         * it can be written to, and if not a new file is created. A boolean
         * result is returned to signify success or failure.
         * 
         * @return A boolean value signify whether the test was sucessful.
         */
    private boolean fileCheck(){
        boolean fileOK = false;
        try{
            File file = new File(filename);
                        
                        // File already exists
            if(file.exists()) {
                /* Only want success if it is a file (not a directory)
                                 * and can be written to.
                                 */
                                if(file.isFile() && file.canWrite()) {
                    fileOK = true;
                }
            }
                        // Create a new file and suceed
            else{
                file.createNewFile();
                fileOK = true;
            }
        }
        catch(IOException e){
            System.out.println(FormatName.formatLogLine(this.toString(), Logger.FATAL, "File check failed - "+e.getMessage()));
        }
        
        return fileOK;
    }

    /**
     * This method is provided if this class wishes to log
     * a message itself.
     *
         * @param source A String representation of the source
         * @param verbosity the verbosity of this message
         * @param message The message to log
         */  
    private void write(String source, int verbosity, String message) {
        write(FormatName.formatLogLine(source, verbosity, message), verbosity);
    }

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

//---ATTRIBUTES---

        /**
         * The filename of the currently open, or last open, file.
         */
    private String filename;
        
        /**
         * A reference to the writer being used.
         */
    private BufferedWriter writer;
        
        /**
         * A boolean signifying whether a file is open or not.
         */
        private boolean open = false;
        
        /**
     * 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:	1.9
Committed:	Tue May 29 17:02:35 2001 UTC (22 years, 11 months ago) by tdb
Branch:	MAIN
Branch point for:	SERVER_PIRCBOT
Changes since 1.8:	+7 -7 lines
Log Message:	Major change in the java package naming. This has been held off for some time now, but it really needed doing. The future packaging of all i-scream products will be; uk.org.iscream.<product>.<subpart>.* In the case of the central monitoring system server this will be; uk.org.iscream.cms.server.* The whole server has been changed to follow this structure, and tested to a smallish extent. Further changes in other parts of the CMS will follow.
#	Content
1	//---PACKAGE DECLARATION---
2	package uk.org.iscream.cms.server.core.loggers;
3
4	//---IMPORTS---
5	import uk.org.iscream.cms.server.util.*;
6	import uk.org.iscream.cms.server.core.*;
7	import java.util.Date;
8	import java.text.DateFormat;
9	import java.util.Locale;
10	import java.io.BufferedWriter;
11	import java.io.File;
12	import java.io.FileWriter;
13	import java.io.IOException;
14
15	/**
16	* The FileLogger is an implementation of the LoggerImpl defined
17	* in the associated interface. It provides quite extensive features to allow
18	* logging ot a text file.
19	*
20	* @author $Author: tdb1 $
21	* @version $Id: FileLogger.java,v 1.8 2001/03/14 23:25:29 tdb1 Exp $
22	*/
23	public class FileLogger implements LoggerImpl {
24
25	//---FINAL ATTRIBUTES---
26
27	/**
28	* The current CVS revision of this class
29	*/
30	public final String REVISION = "$Revision: 1.8 $";
31
32	//---STATIC METHODS---
33
34	//---CONSTRUCTORS---
35
36	/**
37	* Creates a new FileLogger.
38	*
39	* The constructor checks that writing will be ok, then sets up the
40	* writer. It makes use of the fileCheck() method found later on to
41	* ensure writing will be ok, and throws an IOException if there is
42	* a problem. Errors at this stage cannot be logged because the
43	* logging mechanism has not be setup completely, so any problems
44	* are printed to the screen in the same format used for logging.
45	*
46	* @throws IOException if there is a problem with the file check.
47	*/
48	public FileLogger() throws IOException{
49	filename = System.getProperty("uk.org.iscream.cms.server.LoggerClass.FileLogger.filename");
50	// Perform file check to make sure writing is ok
51	if(!fileCheck()){
52	// Have to system.out.println errors because logging mechanism failed !
53	System.out.println(FormatName.formatLogLine(this.toString(), Logger.FATAL, "File check failed, construction terminated"));
54	throw new IOException("File check failed, unable to create FileLog");
55	}
56	try{
57	// Setup the writer
58	writer = new BufferedWriter(new FileWriter(filename, true));
59	// File is now open
60	open = true;
61	}
62	catch(IOException e){
63	System.out.println(FormatName.formatLogLine(this.toString(), Logger.FATAL, "Attempt to setup writer failed - " + e.getMessage()));
64	}
65	// Put an initial line into the log
66	write(toString(), Logger.SYSINIT, "started");
67	}
68
69	//---PUBLIC METHODS---
70
71	/**
72	* The write() method takes a line of text, pre-formatted
73	* and outputs it using a method defined by the actual
74	* implementation. The verbosity is given in case the
75	* implementation wishes to utilise it in the layout -
76	* eg. a different colour or font.
77	*
78	* This instance writes the line to a file.
79	*
80	* @param line A line of formatted text to be logged
81	* @param verbosity the verbosity of this message
82	*/
83	public synchronized void write(String line, int verbosity) {
84	// Check to make sure file is open
85	if(open){
86	// Produce a nicely formatted line for the logfile
87	try{
88	// We have to synchronize here due to problems with two write()'s being called before a newLine()
89	synchronized(writer){
90	// Attempt to write the line
91	writer.write(line);
92	// Best to use newLine() as it will use the correct platform encoding
93	writer.newLine();
94	}
95	// Make sure the line is written immeidiately
96	writer.flush();
97	}
98	catch(IOException e){
99	// We'd best log the error
100	System.out.println(FormatName.formatLogLine(this.toString(), Logger.FATAL, "Writing to logfile failed - " + e.getMessage()));
101	// As it's an IOException we should suspend logging
102	open = false;
103	}
104	}
105	else{
106	// If file is not open we should print this to the screen
107	System.out.println(FormatName.formatLogLine(this.toString(), Logger.FATAL, "Write failed - file not open"));
108	}
109	}
110
111	/**
112	* The clear() method erases the contents of the logfile. It does
113	* this in a very clumsy way - by closing the writer and opening a
114	* new one which is set not to append. This results in the logfile
115	* being overwritten, which effectively erases it.
116	*/
117	public void clear(){
118	// Check file is open
119	if(open){
120	write(toString(), Logger.SYSMSG, "Attempting to clear logfile");
121	try{
122	// Close appending writer
123	open = false;
124	writer.close();
125	// Open a non-appending writer
126	writer = new BufferedWriter(new FileWriter(filename));
127	open = true;
128	}
129	catch(IOException e){
130	// We'd best log the error
131	write(toString(), Logger.ERROR, "Attempt to clear logfile failed - "+e.getMessage());
132	// As it's an IOException we should suspend logging
133	open = false;
134	}
135	}
136	else{
137	// If file is not open we should print this to the screen
138	System.out.println(FormatName.formatLogLine(this.toString(), Logger.FATAL, "Clearing failed - file not open"));
139	}
140	}
141
142	/**
143	* The close() method closes the logfile and no more data can be written.
144	* If writing is attempted after close() has been called an error will be
145	* generated. The open() method can be used to reopen or open a new file.
146	*/
147	public void close(){
148	// Check to see if a file is open
149	if(open){
150	write(toString(), Logger.SYSMSG, "Attempting to terminate logging");
151	try{
152	open = false;
153	writer.close();
154	}
155	catch(IOException e){
156	write(toString(), Logger.ERROR, "Attempt to close logfile failed - " + e.getMessage());
157	// As it's an IOException we should suspend logging
158	open = false;
159	}
160	}
161	else{
162	// If file is not open we should print this to the screen
163	System.out.println(FormatName.formatLogLine(this.toString(), Logger.FATAL, "Close failed - file not open"));
164	}
165	}
166
167	/**
168	* The open() method opens a new file after the close() method has
169	* been called on the FileLog. This enables the user to easily change
170	* the file to which the log is being written. An error is generated
171	* if a file is already open.
172	*
173	* @param filename The new file to write to.
174	* @throws IOException if the file cannot be written to.
175	*/
176	public void open(String filename) throws IOException{
177	// Check to see if a file is open
178	if(open){
179	// If file is already open then we should log that this went wrong
180	write(this.toString(), Logger.WARNING, "Open failed - a file is already open");
181	}
182	else{
183	this.filename = filename;
184	if(!fileCheck()) {
185	// Have to system.out.println errors because logging mechanism failed !
186	System.out.println(FormatName.formatLogLine(this.toString(), Logger.FATAL, "File check failed, construction terminated"));
187	throw new IOException("File check failed, unable to create FileLog");
188	}
189	try{
190	// Setup the writer
191	writer = new BufferedWriter(new FileWriter(filename, true));
192	// File is now open
193	open = true;
194	}
195	catch(IOException e){
196	System.out.println(FormatName.formatLogLine(this.toString(), Logger.FATAL, "Attempt to open writer failed - " + e.getMessage()));
197	}
198	}
199	}
200
201	/**
202	* The suspend() method halts writing to the file by setting the open
203	* boolean to false, and thus blocking the write() method. A line is
204	* written to the logfile beforehand to note that writing has been
205	* suspended.
206	*/
207	public void suspend(){
208	// Check to see if a file is open
209	if(open){
210	// Make a note of the fact that writing has been suspended
211	write(toString(), Logger.SYSMSG, "Writing suspended");
212	// Make sure writing not permitted
213	open=false;
214	}
215	else{
216	// If file is not open we should print this to the screen
217	System.out.println(FormatName.formatLogLine(this.toString(), Logger.FATAL, "Suspend failed - file not open"));
218	}
219	}
220
221	/**
222	* The resume() method resumes writing to the file by setting the open
223	* boolean to true. A line is written to the logfile to signify this
224	* event occuring.
225	*/
226	public void resume(){
227	// Check to see if a file is open
228	if(open){
229	// If file is open we should print this to the screen
230	System.out.println(FormatName.formatLogLine(this.toString(), Logger.FATAL, "Resume failed - file open"));
231	}
232	else{
233	// Permit writing again
234	open=true;
235	// Make a note of the fact that writing has been resumed
236	write(toString(), Logger.SYSMSG, "Writing resumed");
237	}
238	}
239
240	/**
241	* Overrides the {@link java.lang.Object#toString() Object.toString()}
242	* method to provide clean logging (every class should have this).
243	*
244	* This uses the uk.org.iscream.cms.server.util.FormatName class
245	* to format the toString()
246	*
247	* @return the name of this class and its CVS revision
248	*/
249	public String toString() {
250	return FormatName.getName(
251	_name,
252	getClass().getName(),
253	REVISION);
254	}
255
256	//---PRIVATE METHODS---
257
258	/**
259	* The fileCheck() method is used to ensure that writing is ok. It
260	* performs so basic checks to make sure that if the file exists
261	* it can be written to, and if not a new file is created. A boolean
262	* result is returned to signify success or failure.
263	*
264	* @return A boolean value signify whether the test was sucessful.
265	*/
266	private boolean fileCheck(){
267	boolean fileOK = false;
268	try{
269	File file = new File(filename);
270
271	// File already exists
272	if(file.exists()) {
273	/* Only want success if it is a file (not a directory)
274	* and can be written to.
275	*/
276	if(file.isFile() && file.canWrite()) {
277	fileOK = true;
278	}
279	}
280	// Create a new file and suceed
281	else{
282	file.createNewFile();
283	fileOK = true;
284	}
285	}
286	catch(IOException e){
287	System.out.println(FormatName.formatLogLine(this.toString(), Logger.FATAL, "File check failed - "+e.getMessage()));
288	}
289
290	return fileOK;
291	}
292
293	/**
294	* This method is provided if this class wishes to log
295	* a message itself.
296	*
297	* @param source A String representation of the source
298	* @param verbosity the verbosity of this message
299	* @param message The message to log
300	*/
301	private void write(String source, int verbosity, String message) {
302	write(FormatName.formatLogLine(source, verbosity, message), verbosity);
303	}
304
305	//---ACCESSOR/MUTATOR METHODS---
306
307	//---ATTRIBUTES---
308
309	/**
310	* The filename of the currently open, or last open, file.
311	*/
312	private String filename;
313
314	/**
315	* A reference to the writer being used.
316	*/
317	private BufferedWriter writer;
318
319	/**
320	* A boolean signifying whether a file is open or not.
321	*/
322	private boolean open = false;
323
324	/**
325	* This is the friendly identifier of the
326	* component this class is running in.
327	* eg, a Filter may be called "filter1",
328	* If this class does not have an owning
329	* component, a name from the configuration
330	* can be placed here. This name could also
331	* be changed to null for utility classes.
332	*/
333	private String _name = Core.NAME;
334
335	//---STATIC ATTRIBUTES---
336
337	}