You will often need to verify the correct running of your code. While you can use the debug mode of an IDE or compiler, you can also include some debugging code as well. First, use a global static boolean variable in the class that contains the “main” method (i.e. “debugMode”) to indicate whether or not you want it to display debug messages:

    static boolean debugMode;

Then, where you want a debug message, write:

    MyClass.debug("This is a debug message"/*type what you need*/);

“MyClass” is the name of the class that contains the “main” method; it is a call for a method whose code should be:

    public static void debug(String message){      if(debugMode)         System.out.println(message);   }

Obviously this method should be in the class that contains the “main” method.

In order to select the debug mode, you should type an extra parameter in the command to execute your application (i.e. “–debug”) and include some code in the “main” method:

    public static void main(String args[]){      if(args.length > 0)         if(args[args.length -1].equals("--debug"))            debugMode = true;      ...   }

Finally, when you want to run your application in debug mode, type:

    java MyClass [parameters] --debug