java - 在Applet中显示图像

Question

package org.kodejava.example.applet;

import java.applet.Applet;
import java.awt.*;

public class AppletGetImage extends Applet {
    private Image logo;

    @Override
    public void init() {

        logo = getImage(getDocumentBase(), "/images/logo.png");
    }

    @Override
    public void paint(Graphics g) {
        g.drawRect(0, 0, getWidth() - 1, getHeight() - 1);
        g.drawImage(logo, 10, 10, this);
    }
}

问题:

1. compalsary包在所有java程序中声明吗？
2. 私有(private)图像 Logo ；该变量可以在小程序类中用于什么目的？
3. public void init()该方法可以在 applet 类中用于什么目的？

Answer 1

compalsary package declare in all java program?

没有。请参阅此处了解更多信息:Java Package

private Image logo; for which purpose this variable can be use in applet class?

请参阅此处:Declaring Member Variables in Java

public void init() for which purpose this method can be use in applet class?

请参阅此处:Life Cycle of an Applet和Applet init() method