java中的键盘监听器失效问题

Question

package com.tarena.swing;

import java.awt.event.KeyAdapter;
import java.awt.event.KeyEvent;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;

import javax.swing.JFrame;
import javax.swing.JPanel;

public class TestListener extends JPanel {
public void action(){
KeyAdapter k=new KeyAdapter() {
public void keyReleased(KeyEvent k){
System.out.println("sssss");
}
};
this.addKeyListener(k);
MouseAdapter l=new MouseAdapter() {
public void mouseMoved(MouseEvent e){
System.out.println(e.getX()+" ,"+e.getY());
}
};
this.addMouseMotionListener(l);

}
public static void main(String[] args) {
    JFrame j=new JFrame();
    TestListener l=new TestListener();
    j.setSize(400,654);
    j.add(l);
    j.setVisible(true);
    j.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    j.setAlwaysOnTop(true);
    l.action();

}

}

为TestSwing添加键盘监听事件和鼠标移动监听事件 但是键盘的监听失效 只有鼠标移动的能在控制台输出鼠标坐标

Answer 1

键盘监听应该添加JTextArea，在TextArea上进行输入接收
private JTextArea text = new JTextArea();
text.addKeyListener(k);