import java.awt.*;

import java.awt.event.*;

import javax.swing.*;

import java.math.*;

import java.util.*;

public class b{

    public static void main(String args[])

    {

        MathWindow win=new MathWindow();

    }

}

class MathWindow extends JFrame{

     JTextField inputText,showText;

     MathWindow(){

          inputText=new JTextField(10);

          showText=new JTextField(10);

          inputText.addActionListener(new ActionListener(){

              public void actionPerformed(ActionEvent e){

                  int n=0,i=0;

                  String s=inputText.getText();

                  try{

                       StringTokenizer fenxi=new StringTokenizer(s," ");

                       for(i=0;fenxi.hasMoreTokens();i++){

                             String str=fenxi.nextToken();

                             n+=Integer.parseInt(str);

                       }

                       showText.setText(String.valueOf(n/i));

                  }

                  catch(NumberFormatException ee)

                  {

                        showText.setText("输入字符串");

                        inputText.setText(null);

                  }

             }

           });

           setLayout(new FlowLayout());

           add(inputText);

           add(showText);

           setBounds(100,100,260,190);

           setVisible(true);

           validate();

           setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);

     }

}

运行结果如下：