java登录界面背景图片

① java怎么添加背景图片

这是我以前的一个小代码你可以看看
public class demo_9 extends JFrame {
jsplitPane jsp = null;
JList jlist;
JLabel jlabel;

public static void main(String[] args) {
demo_9 a = new demo_9();

}
public demo_9(){
String []words ={"boy","girl"};
JList jlist = new JList(words);
jlabel = new JLabel(new ImageIcon("Image//真三.gif")); //这里就是引入图片了
//拆分窗格
jsp = new JSplitPane(JSplitPane.HORIZONTAL_SPLIT,jlist,jlabel);
jsp.setDividerLocation(70);
//设置可以伸缩
jsp.setOneTouchExpandable(true);
this.add(jsp);
this.setTitle("test");
this.setSize(400,300);
this.setLocation(400,200);
this.setVisible(true);
}

}
步骤：首先先在project里新建个文件夹（Folder），然后把你要插入的图片复制黏贴到这个文件夹里面。
例如我那个引入的图片代码：jlabel = new JLabel(new ImageIcon("Image//真三.gif"));
我new一个folder叫Image，图片名称叫"真三.gif"

② java登陆界面如何插入背景图片

直接上代码了，这是我以前写的
packageam_2;

importjava.awt.*;
importjavax.swing.*;

publicclassJLayeredPane_1extendsJFrame{
publicJLayeredPane_1(){
this.setSize(300,400);
JLayeredPanelayeredPane=this.getLayeredPane();
layeredPane.add(newBackgroundPanel(),newInteger(0));//thesameto
//layeredPane.add(panelBg);
layeredPane.add(newPanelContent(),newInteger(1));

this.setLocationRelativeTo(null);
this.setVisible(true);
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}

{
publicBackgroundPanel(){
this.add(newJLabel(getIcon()));
this.setBounds(0,0,300,400);

}

publicImageIcongetIcon(){

finalImageimageBg=Toolkit.getDefaultToolkit().getImage(
this.getClass().getResource("/img/0.jpg"));
ImageIconimageIcon=newImageIcon(imageBg);
returnimageIcon;
}

@
publicvoidpaint(Graphicsg){

ImageimageBg=Toolkit.getDefaultToolkit().getImage(
this.getClass().getResource("/img/0.jpg"));
g.drawImage(imageBg,0,0,300,400,null);
}
}

{
publicPanelContent(){

JButtonbutton=newJButton("测试按钮1");
JButtonbutton2=newJButton("测试按钮2");
JButtonbutton3=newJButton("测试按钮3");

this.setBounds(100,100,100,100);
this.setOpaque(false);//设置为透明
this.add(button);
this.add(button2);
this.add(button3);
}
}

/**
*@paramargs
*@throwsException
*/
publicstaticvoidmain(String[]args){
//TODOAuto-generatedmethodstub
JLayeredPane_1frame=newJLayeredPane_1();

}

}