如何过滤我在JTextField中输入的内容并显示过滤结果？

package javaisnotbannana;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.*;
import javax.swing.*;
public class  Javaisnotbannana{

    public static void main(String[] args) { 
        window();
    }       
////////////////////////////////////////////////////
public static void window()
    {
     JFrame window= new JFrame();
     JPanel jp = new JPanel();
     JLabel jl = new JLabel();
     JTextField jt = new JTextField(30);
     JButton jb = new JButton("Enter");
     window.setTitle("ThisisTitleofWindow");
     window.setVisible(true);
     window.setSize(500, 500);
     window.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
     //textfield
     jp.add(jt);
     jt.addActionListener(new ActionListener()
     {
     public void actionPerformed(ActionEvent e)
     {
     String inoutt = jt.getText();

     jl.setText(inoutt); 
     }
     });
package javaisnotbannana;
import java.awt.event