logging - Java custom logger issues -

i have custom logger class:

import java.io.outputstream; import java.io.printstream;  public class logger extends printstream{      public logger(outputstream outputstream) {         super(outputstream);         logheader();     }      private void logheader(){         (int i=0; i<20; i++) print("#");         print("program execution start: ");         print(calendarclock.getinittimestamp());         (int i=0; i<20; i++) print("#");         println();     }      public void logfooter(){         (int i=0; i<=20; i++) print("#");         print("program execution stop: ");         print(calendarclock.getcurrenttimestamp());         (int i=0; i<=20; i++) print("#");         println("\n");     }      @override     public void print(string arg0) {         super.print(arg0);         if (this.out != system.out) system.out.print(arg0);     }      @override     public void println(string arg0) {         super.println(arg0);         if (this.out != system.out) system.out.println(arg0);     } } 

and here main class:

public class main {     @suppresswarnings("resource")     public static void main(string[] args){         file logfile = new file("data/test.log");         logger logger;          try{             if (!logfile.exists()) logfile.createnewfile();             logger = new logger(new fileoutputstream(logfile, false));         } catch (ioexception e) {             logger = new logger(system.out);          }                                            logger.println("hello world.");         logger.println("foo bar");                   logger.logfooter();         logger.close();      }  } 

firstly, eclipse keeps displaying warning @ logger = new logger(system.out); inside catch(ioexception e): resource leak: 'logger' not closed @ location. have add @suppresswarnings("resource") make disappear.

secondly program outputs following console:

####################program execution start: 2015-10-27 10:55:51####################hello world.hello world. foo barfoo bar #####################program execution stop: 2015-10-27 10:55:51##################### 

while logs file correctly:

####################program execution start: 2015-10-27 10:55:51#################### hello world. foo bar #####################program execution stop: 2015-10-27 10:55:51##################### 

lastly, if run following code:

public class main {     @suppresswarnings("resource")     public static void main(string[] args){         file logfile = new file("data/test.log");         logger logger;          try{             throw new ioexception("threw exception!");             /*if (!logfile.exists()) logfile.createnewfile();             logger = new logger(new fileoutputstream(logfile, false));*/         } catch (ioexception e) {             logger = new logger(system.out);             logger.println(e.getmessage());         }                    logger.println("hello world.");         logger.println("foo bar");         logger.logfooter();         logger.close();      }  } 

the output correctly printed as:

####################program execution start: 2015-10-27 10:59:18#################### threw exception! hello world. foo bar #####################program execution stop: 2015-10-27 10:59:18##################### 

obviously, seems beyond understanding, , explanation of behavior appreciated.

update: solved issue of no new line @ end of header overriding null argument println:

@override public void println() {     super.println();     if (out != system.out) system.out.println(); } 

now output of first main is:

####################program execution start: 2015-10-27 11:15:30#################### hello world.hello world. foo barfoo bar #####################program execution stop: 2015-10-27 11:15:30##################### 

i used debugger see sequence of code execution, , found printstream class implements prinln(arg0) call print(arg0) , newline() equivalent println(). every time println(arg0) called in logger, arg0 printed stdout twice, once in print(arg0) , once in println(arg0).

to overcome problem, changed implementation of println(arg0) in logger class this:

@override public void println(string arg0) {     print(arg0);     println(); }