Question

Java 为什么下面的程序会出错呢？？

“Java_2不是抽象的，并且未覆盖java.awt.event.WindowListener中的抽象方法windowClosing(java.awt.event.WindowListener)”?
import java.awt.Color;
import java.awt.Frame;
import java.awt.event.ActionEvent;
import java.awt.event.WindowEvent;
import java.awt.event.WindowListener;

/*
* To change this template, choose Tools | Templates
* and open the template in the editor.
*/
/**
*
* @author Administrator
*/
public class Java_2 extends Frame implements WindowListener {

public static void main(String args[]) {
Java_2 fr = new Java_2();
//*********Found**********
fr.setSize(200, 100);
fr.setBackground(Color.green);
//*********Found**********
fr.addWindowListener(fr);
fr.setVisible(true);
}

//*********Found**********
public void windowClosing(ActionEvent e) {
System.exit(0);
}

public void windowClosed(WindowEvent e) {
}

public void windowOpened(WindowEvent e) {
}

public void windowIconified(WindowEvent e) {
}

public void windowDeiconified(WindowEvent e) {
}

public void windowActivated(WindowEvent e) {
}

public void windowDeactivated(WindowEvent e) {
}
}

Answer 1

你的java_2类没实现java.awt.event.WindowListener中的抽象方法windowClosing(java.awt.event.WindowListener)

你建个空方法他就不暴错了

Answer 2

你用什么工具写代码的，eclipse提示很清楚，你少实现一个方法

public void windowClosing(WindowEvent e) {
// TOM Auto-generated method stub

}

你有一个
public void windowClosing(ActionEvent e) {
System.exit(0);
}
方法，不过参数不对，所以不行

Answer 3

public void windowClosing(ActionEvent e) {
System.exit(0);
}
改为
public void windowClosing(WindowEvent e) {
System.exit(0);
}