动手动脑

package lain1;
import javax.swing.*;

public class RollDie {
   public static void main( String args[] )
   {
      int frequency1 = 0, frequency2 = 0,
          frequency3 = 0, frequency4 = 0,
          frequency5 = 0, frequency6 = 0, face;
   
      // summarize results
      for ( int roll = 1; roll <= 6000; roll++ ) {
         face = 1 + (int) ( Math.random() * 6 );
   
         switch ( face ) {
            case 1:
               ++frequency1;
               break;
            case 2:
               ++frequency2;
               break;
            case 3:
               ++frequency3;
               break;
            case 4:
               ++frequency4;
               break;
            case 5:
               ++frequency5;
               break;
            case 6:
               ++frequency6;
               break;
         }
      }

      JTextArea outputArea = new JTextArea( 7, 10 );

      outputArea.setText(
         "Face\tFrequency" +
         "\n1\t" + frequency1 +
         "\n2\t" + frequency2 +
         "\n3\t" + frequency3 +
         "\n4\t" + frequency4 +
         "\n5\t" + frequency5 +
         "\n6\t" + frequency6 );

      JOptionPane.showMessageDialog( null, outputArea,
         "Rolling a Die 6000 Times",
         JOptionPane.INFORMATION_MESSAGE );
      System.exit( 0 );
   }
}

// MethodOverload.java
// Using overloaded methods
package lain1;
public class MethodOverload {

    public static void main(String[] args) {
        System.out.println("The square of integer 7 is " + square(7));
        System.out.println("\nThe square of double 7.5 is " + square(7.5));
    }

    public static int square(int x) {
        return x * x;
    }

    public static double square(double y) {
        return y * y;
    }
}