addKeyListener()怎样监听的？为啥我输了内容没反应

[程序猿厨子]

import java.awt.Component;
import java.awt.event.KeyAdapter;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import java.util.Scanner;
public class B extends Component{
public static void main(String[] args) {
	// TODO Auto-generated method stub
	B b = new B();
	b.addKeyListener(new KeyAdapter() {
		 public void keyPressed(KeyEvent e)
         {
             if(e.getKeyCode()==KeyEvent.VK_G)
           
                System.exit(0);
             //组合键
             else if(e.isControlDown()&&e.getKeyCode()==KeyEvent.VK_ENTER)
                System.exit(0);
         else System.out.println(e.getKeyChar()+"..."+KeyEvent.getKeyText(e.getKeyCode()));
        }
	});
}
	}

为什么运行之后随便输个字母都不会打印出最后一行的内容呢

[你好sun悟空]

因为你添加完监听器之后,程序直接走完了,虚拟机都关闭了,你还怎么运行呢