Can I have macros in Java source files

Question

In my program I\'m reading integers form console many times. Every time, I need to type this line.

new Scanner(System.in).nextInt(); 

I\'m

Answer 1

Java doesn't support macros simply because the designers of Java chose not to include that functionality. The longer answer is that Java doesn't have a preprocessor the way C/C++ does and cannot perform that functionality that the preprocessor normally would. The way I would implement this is simply create a wrapper class that wraps up the Scanner constructor calls. Perhaps something like

public static int readInt(){
  return new Scanner(System.in).nextInt();
}

Or, better yet,

public class ScannerWrapper{
  private static Scanner instance = null;

  public static int readInt(){
   if (instance == null){
     instance = new Scanner(System.in);
   }

   return instance.nextInt();
 }