java - 编译我的java小程序时出现两个警告

Question

package homework1;

import java.applet.Applet;
import java.awt.Graphics;

public class Homework1A extends Applet {

    public  void paint( Graphics g ){
        g.drawString("CIS 35A Student Learning Outcomes ",40,60);
    }
}

这是我收到的警告

The serializable class Homework1A does not declare a static final serialVersionUID field of type long 
Homework1A.java    /homework1/src/homework1    line 5    Java Problem

还有另一个类似的警告

Warning: Can't read AppletViewer properties file:

但在我运行代码几次后它就消失了。

Answer 1

您的类中需要一个串行版本 UID，例如:private static Final long serialVersionUID = 1L;。

您可以将此作为引用:Serial IDs