Log.java :  » Game » project-narwhal » gameEngine » Java Open Source

//********************************************************************************************
//*
//*    This file is part of Project Narwhal.
//*
//*    Project Narwhal 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 3 of the License, or
//*    (at your option) any later version.
//*
//*    Project Narwhal 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 Project Narwhal.  If not, see <http://www.gnu.org/licenses/>.
//*
//********************************************************************************************
package gameEngine;

import java.io.BufferedWriter;
import java.io.FileWriter;
import java.util.Calendar;
import java.text.SimpleDateFormat;

public class Log 
{
  static BufferedWriter logFile = null;
    
  /**
   * JJ> Initialize the logging system
   * @return true if it was successful.
   */
  public static boolean initialize() {
       try 
       {              
            //Construct the BufferedWriter object
            logFile = new BufferedWriter(new FileWriter("game.log"));
            
            //Start writing to the output stream
            message("System date is: " +  getDate());
            message("Initializing logging system... Success!");
            return true;
        } 
        catch (Exception ex) 
        {
            ex.printStackTrace();
        }   
     
     //Something went wrong
     return false;
  }
    
  
  /**
   * JJ> Writes the specified text to the log file and adds a new line feed  
   * @param rawText
   */
  public static void message(String rawText) {
    String text = "INFO: " + rawText; 
    System.out.println(text);
    println(text);
  }
  
  /**
   * JJ> Writes the specified warning to the log file and adds a new line feed  
   * @param rawText
   */
  public static void warning(String rawText) {
    String text = "WARNING: " + rawText; 
    System.err.println(text);
    println(text);
  }
  public static void warning(Exception ex) { warning(ex.toString()); }
  
  /**
   * JJ> Writes the specified error to the log file and then terminates the program  
   * @param rawText
   */
  public static void error(String rawText) {
    String text = "FATAL ERROR: " + rawText; 
    System.err.println(text);
    println(text);
    close();      //TODO: replace with GameWindow.exit()
    System.exit(-1);
  }
  public static void error(Exception ex) { error(ex.toString()); }
  
  /**
   * JJ> Writes the specified text to the log file
   * @param text
   */
  public static void println(String text) { print(text, true); }
  public static void print(String text, boolean newLine) {
    if( logFile == null ) return;
    
    String message = getTime() + " " + text;
      try  
      {   
          //Writing happens live, we want the log to be up to date if the 
          //program crashes for some reason
          logFile.write(message);
      if(newLine) logFile.newLine();   //We use this function instead of \n, since new line feeds are system dependent
          logFile.flush();
       }          
       catch (Exception ex) 
       {
         ex.printStackTrace();
       }           

  }
  
  //JJ> Helper functions to quickly get time and date
    static private String getDate() {
        Calendar cal = Calendar.getInstance();
        SimpleDateFormat date = new SimpleDateFormat("yyyy-MM-dd");
      return date.format( cal.getTime() );
    }
    static private String getTime() {
        Calendar cal = Calendar.getInstance();
        SimpleDateFormat date = new SimpleDateFormat("HH:mm:ss");
      return date.format( cal.getTime() );
    }
  
  /**
   * JJ> Close log file
   */
    public static void close() {
    if (logFile == null) return; 

    //Close the BufferedWriter
        try  
        {
          message("Shutting down logging system...");
            logFile.close();
        } 
        catch (Exception ex) 
        {
            ex.printStackTrace();
        }
  }
}