程序代码：

import javax.swing.JOptionPane;
import java.awt.*;
import javax.swing.*;


 public class MaxTest extends JApplet {
       JLabel  A1;
         int shuzhu[ ];
       public void init()
       {
        Container  contn = getContentPane();
        contn.setLayout( new FlowLayout() );

        A1 = new JLabel();  

        String input;
        int num1, num2, num3;
        input = JOptionPane.showInputDialog(" please input num1: ");
        num1 = Integer.parseInt( input );
        input = JOptionPane.showInputDialog(" please input num2: ");
        num2 = Integer.parseInt( input );
        input = JOptionPane.showInputDialog(" please input num3: ");
        num3 = Integer.parseInt( input );
        displayMax(num1, num2, num3);
        contn.add( A1 );
       }   
      
       public void displayMax( int x, int y, int z )
       {
            int max = 0;
            max = x>y?x:y;
            max = z>max?z:max;
            A1.setText(""+max);
       }            

 }