Log.java

package com.jaivox.util;

import java.util.logging.*;

/**
 * Creates a logger that can then be used to log messages at various
 * levels.
 */

public class Log {

	public static Logger logger;
	
	static Handler console;
	static Handler file;
	
	public static boolean initialized = false;
	static boolean reported = false;
	
/**
 * It is not necessary to create a logger. If there is no logger present,
 * you get one message asking to create a logger. If a logger is created,
 * you will get the messages at the selected level of fineness on the
 * console.
 * We initially create the logger with the FINEST level, thus after a
 * logger is created, the creating program should set the logging level
 * to the desired level of fineness.
 */
	public Log () {
		initialize ();
	}
	
	void initialize () {
		// set this as a top level logger, to control console level
		logger = Logger.getLogger ("com.jaivox.util.Log");
		logger.setUseParentHandlers (false);
		Handler hConsole = new ConsoleHandler ();
		hConsole.setFormatter (new Logformat ());
		hConsole.setLevel (Level.FINEST);
		logger.addHandler (hConsole);
		logger.setLevel (Level.FINEST);
	    // what is the level of this logger?
	    String s = logger.getLevel ().toString ();
		System.out.println ("Logger log level after creating "+s);
		initialized = true;
	}
	
	static boolean check () {
		if (!initialized) {
			if (!reported) {
				System.out.println ("Please create a com.jaivox.util.Log object");
				reported = true;
			}
			return false;
		}
		else return true;
	}
	
/**
 * Log the given message at the given level
@param level
@param s
 */
	public static void log (Level level, String s) {
		if (check ()) logger.log (level, s);
	}
	
/**
 * Set the logging level using a Level value.
@param level
 */
	public static void setLevel (Level level) {
		if (check ()) logger.setLevel (level);
	}
	
/**
 * Set the logging level using one of the words "severe", "warning" etc
 * corresponding to logging levels. This function is case insensitive.
@param word
 */
	
	public static void setLevelByName (String word) {
		String s = word.toUpperCase ();
		Level level = Level.SEVERE;
		if (s.equals ("SEVERE")) level = Level.SEVERE;
		if (s.equals ("WARNING")) level = Level.WARNING;
		if (s.equals ("INFO")) level = Level.INFO;
		if (s.equals ("CONFIG")) level = Level.CONFIG;
		if (s.equals ("FINE")) level = Level.FINE;
		if (s.equals ("FINER")) level = Level.FINER;
		if (s.equals ("FINEST")) level = Level.FINEST;
		logger.setLevel (level);
		Level ll = logger.getLevel ();
		System.out.println ("Logging level now "+ll.toString ());
	}
	
/**
 * The default logger sends logging messages to the screen. This function
 * can be used to designate a file also as a log output.
@param filename
 */
	public static void addFileLog (String filename) {
		if (!check ()) return;
		try {
			file = new FileHandler (filename);
			logger.addHandler (file);
		}
		catch (Exception e) {
			e.printStackTrace ();
		}
	}

/**
 * Open an existing file and log to that.
@param filename
 */
	public static void openFile (String filename) {
		if (!check ()) return;
		try {
			file = new FileHandler (filename);
			logger.addHandler (file);
		}
		catch (Exception e) {
			e.printStackTrace ();
		}
	}

/**
 * Stop logging to the console, i.e. screen
 */
	public static void clearConsole () {
		if (check ()) logger.removeHandler (console);
	}
	
/**
 * Stop logging to a file
 */
	public static void clearFile () {
		if (check ()) {
			file.close ();
			logger.removeHandler (file);
		}
	}

/**
 * Close the file log if any
 */
	public static void closeFile () {
		if (check ()) {
			file.close ();
			logger.removeHandler (file);
		}
	}

/**
 * Log Level.FINE messages
@param s
 */
	
	public static void fine (String s) {
		if (check ()) logger.fine (s);
	}
	
	/**
	 * Log Level.FINER messages
	@param s
	 */
		
	public static void finer (String s) {
		if (check ()) logger.finer (s);
	}
	
	/**
	 * Log Level.FINEST messages
	@param s
	 */
		
	public static void finest (String s) {
		if (check ()) logger.finest (s);
	}
	
	/**
	 * Log Level.INFO messages
	@param s
	 */
		
	public static void info (String s) {
		if (check ()) logger.info (s);
	}
	
	/**
	 * Log Level.SEVERE messages
	@param s
	 */
		
	public static void severe (String s) {
		if (check ()) logger.severe (s);
	}
	
	/**
	 * Log Level.WARNING messages
	@param s
	 */
		
	public static void warning (String s) {
		if (check ()) logger.warning (s);
	}
	
}