Java自动装箱和扩展

public class Tester {

   public static void main(String args[]) {

      Tester tester = new Tester();

      short c = 1, d = 2;

      int e = 1, f = 2;

      System.out.println(tester.add(c, d));

      System.out.println(tester.add(e, f));

   }

   public int add(short a, short b) {

      System.out.println("short");

      return a + b;

   }

   public int add(int a, int b) {

      System.out.println("int"); return a + b;

   }

}