请大虾指点一下
import javax.swing.*;
public class kongjian8 extends JFrame
{
 JSplitPane jspOuter=new JSplitPane(JSplitPane.HORIZONTAL_SPLIT,true);
 JSplitPane jspInner=new JSplitPane(JSplitPane.VERTICAL_SPLIT,true);
public kongjian8()
{
jspOuter.setLeftComponent(new JLabel("这里是左边窗格",JLabel.CENTER));
jspInner.setRightComponent(jspInner);
jspInner.setTopComponent(new JLabel("这里是右上窗格",JLabel.CENTER));
jspInner.setDividerLocation(150);
jspOuter.setDividerSize(4);
jspInner.setDividerSize(4);
this.add(jspOuter);
this.setTitle("分隔窗格示例");
this.setResizable(false);
this.setBounds(100,100,425,250);
this.setVisible(true);
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
public static void main(String args[])
{
kongjian8 kj=new kongjian8();
}
}Exception in thread "main" java.lang.IllegalArgumentException: adding container'
s parent to itself
        at java.awt.Container.checkAddToSelf(Container.java:420)
        at java.awt.Container.addImpl(Container.java:1038)
        at javax.swing.JSplitPane.addImpl(JSplitPane.java:1015)
        at java.awt.Container.add(Container.java:927)
        at javax.swing.JSplitPane.setRightComponent(JSplitPane.java:503)
        at kongjian8.<init>(kongjian8.java:9)
        at kongjian8.main(kongjian8.java:23)