import java.awt.FlowLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JTextField;
public class E_2{
    public static void main(String args[]){
        MathWindow win=new MathWindow();
    }
}
class MathWindow extends JFrame implements ActionListener{
    JTextField inputText,showUnicode;
    JButton button;
    MathWindow(){
        inputText=new JTextField(10);
        showUnicode=new JTextField(10);
        button=new JButton("排序");
        button.addActionListener(this);
        inputText.addActionListener(this);
        setLayout(new FlowLayout());
        add(inputText);
        add(button);
        add(showUnicode);
        setBounds(100,100,260,190);
        setVisible(true);
        validate();
        setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
   }
   public void actionPerformed(ActionEvent e){
        String s=inputText.getText();
        char c[] = null;
        char tem;
        StringBuffer str=new StringBuffer();
        for(int i=0;i<s.length();i++)
           c[i]=s.charAt(i);
        for(int i=0;i<s.length()-1;i++){
           for(int j=i+1;j<s.length();j++){
           if(c[i]<c[j])
           {
               tem=c[j];
               c[j]=c[i];
               c[i]=tem;
           }
           str.append(c);
           str.append(",");
           }
        }
        showUnicode.setText(new String(str));
   }
}
题目要求是在一个文本框中输入数，再另一个文本框中输出数的排序的结果，请高手指点

请把代码加到我的代码中   请高手指点