P2 Panoptikum

System.out is handy for quick and dirty debugging, but sometime you want to turn it of.

There are three solutions

1. Have an output object that you pass to all methods that do printing. Make two implementation of class Out, a class Verbose that prints to the console and a class Silence that does not print.

   public interface Out {
       public void put(String text);
   }
   
   public class Whatever {
       public void method(Out out, Object... args) {
           ...
           out.put("Hic sunt leones.");
           ...
       }
   }
   
   Out out = new Verbose();
   new Whatever().method(out, ...);
   

2. Have static method that uses a static flag to switch between printing and silence.

   public class Out {
       public static boolean SILENT = true;
       public static void put(String text) {
           if (!SILENT) System.out.println(text);
       }
   }
   
   public class Whatever {
       public void method(Object... args) {
           ...
           Out.put("Hic sunt leones.");
           ...
       }
   }
   
   Out.SILENCE = false;
   new Whatever().method(...);
   

3. Redirect the standard output to custom PrintStream instance. I wont go into details here, because this is black magic. But it is good to know that this can be done, for example to silence a third-party library. (In case you want to take this path, see the API documentation of System#setOut)

akuhn Java