各位仁人志士快进来看看啊！！

import javax.swing.*;
import java.awt.*;
class  FrameTest extends JFrame 
{
public FrameTest()
{
super("学生信息编辑管理器");
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setVisible(true);
setSize(600,400);
}
}
class PanelTest extends FrameTest
{
JPanel mainpanel,subpanel1,subpanel2,subpanel3,
subpanel4,subpanel5,subpanel6,subpanel7;//声明JFrame类对象
   


public PanelTest()  //创建构造函数
{
mainpanel=new JPanel();
subpanel1=new JPanel();   //创建JPane类对象
subpanel2=new JPanel();
subpanel3=new JPanel();
subpanel4=new JPanel();
subpanel5=new JPanel();
subpanel6=new JPanel();
subpanel7=new JPanel();
  
//panelObj.setBackground(Color.white);   //设置面板颜色
//getContentPane().add(panelObj);       //将面板添加到窗体
}
}
class customerTest extends PanelTest
{
JLabel labelname,labelgrade,labelclass,labelsex,labelage,headlabel,labelObj7;  
JTextField textFieldObj1,textFieldObj2,textFieldObj3;  
JRadioButton rButObj1,rButObj2;
JButton buttonObj;
JCheckBox checkBoxObj;
JList listObj;
JScrollPane ScrollPaneObj;
JComboBox comboBoxObj;
JTable tableObj;
GridBagLayout gblayoutObj1,gblayoutObj2,gblayoutObj3,gblayoutObj4,
gblayoutObj5,gblayoutObj6,gblayoutObj7,gblayoutObj;
GridBagConstraints gbcObj1,gbcObj2,gbcObj3,gbcObj4,gbcObj5,gbcObj6,gbcObj7,gbcObj ;
JButton buttonObj1,buttonObj2;
 
public void customerTest()
{
headlabel=new JLabel("************************学员信息编辑器************************");
mainpanel.add(headlabel);
checkBoxObj =new JCheckBox("是否注册",null,true);
mainpanel.add(checkBoxObj);        gblayoutObj1=new GridBagLayout(); 
    gbcObj1=new GridBagConstraints();
subpanel1.setLayout(gblayoutObj1);
labelname=new JLabel("姓名:");
gbcObj1.anchor=GridBagConstraints.EAST;
gblayoutObj1.setConstraints(labelname,gbcObj1);
textFieldObj1=new JTextField(15);
textFieldObj1.setEnabled(false);
gbcObj1.anchor=GridBagConstraints.WEST;
gblayoutObj1.setConstraints(textFieldObj1,gbcObj1);
subpanel1.add(labelname);
subpanel1.add(textFieldObj1);
mainpanel.add(subpanel1);

gblayoutObj2=new GridBagLayout(); 
    gbcObj2=new GridBagConstraints();
    subpanel2.setLayout(gblayoutObj2);
labelage=new JLabel("年龄:");
gbcObj2.anchor=GridBagConstraints.EAST;
gblayoutObj2.setConstraints(labelage,gbcObj2);
textFieldObj2=new JTextField(3);
textFieldObj2.setEnabled(false);
gbcObj2.anchor=GridBagConstraints.WEST;
gblayoutObj2.setConstraints(textFieldObj2,gbcObj2);
subpanel2.add(labelage);
subpanel2.add(textFieldObj2);
mainpanel.add(subpanel2);

        
gblayoutObj3=new GridBagLayout(); 
    gbcObj3=new GridBagConstraints();
    subpanel3.setLayout(gblayoutObj3);
labelsex=new JLabel("性别:");
gbcObj3.anchor=GridBagConstraints.WEST;
        gbcObj3.gridx=0;
        gbcObj3.gridy=0;
gblayoutObj3.setConstraints(labelsex,gbcObj3);
rButObj1=new  JRadioButton("男",false);
rButObj1.setEnabled(false);
gbcObj3.anchor=GridBagConstraints.EAST;
        gbcObj3.gridx=1;
        gbcObj3.gridy=0;
gblayoutObj3.setConstraints(rButObj1,gbcObj3);
rButObj2=new  JRadioButton("女",true);
rButObj1.setEnabled(false);
gbcObj3.anchor=GridBagConstraints.WEST;
        gbcObj3.gridx=1;
        gbcObj3.gridy=1;
gblayoutObj3.setConstraints(rButObj2,gbcObj3);
ButtonGroup buttonGroupObj =new ButtonGroup();
buttonGroupObj.add(rButObj1);
buttonGroupObj.add(rButObj2);
subpanel3.add(labelsex);
subpanel3.add(rButObj1);
subpanel3.add(rButObj2);
mainpanel.add(subpanel3);
 



gblayoutObj4=new GridBagLayout(); 
    gbcObj4=new GridBagConstraints();
    subpanel4.setLayout(gblayoutObj4);
labelgrade=new JLabel("年级:");
gbcObj4.anchor=GridBagConstraints.EAST;
        gbcObj4.gridheight=1;
gblayoutObj4.setConstraints(labelgrade,gbcObj4);
String listStr[]={"一年级","二年级",
"三年级","四年级","五年级"};
listObj=new JList(listStr);
listObj.setFixedCellWidth(100); 
listObj.setVisibleRowCount(4); 
//panelObj.add(listObj);
ScrollPaneObj=new JScrollPane(listObj ,
JScrollPane.VERTICAL_SCROLLBAR_ALWAYS,                                        
    JScrollPane.HORIZONTAL_SCROLLBAR_ALWAYS ); 
gbcObj4.anchor=GridBagConstraints.WEST;
gbcObj4.weightx=1.0;
gbcObj4.weightx=0.0;
gbcObj4.gridheight=4;
gblayoutObj3.setConstraints(ScrollPaneObj,gbcObj4);
subpanel4.add(labelgrade);
subpanel4.add(ScrollPaneObj);
mainpanel.add(subpanel4);




gblayoutObj5=new GridBagLayout(); 
    gbcObj5=new GridBagConstraints();
subpanel5.setLayout(gblayoutObj5);
labelclass=new JLabel("系别:");
gbcObj4.anchor=GridBagConstraints.EAST;
gblayoutObj4.setConstraints(labelclass,gbcObj5);
String ComBoxTestObjStr[]={"计算机系","物理系","电子信息工程",
           "化学系","中文系","生物系"};
        comboBoxObj=new JComboBox(ComBoxTestObjStr);
comboBoxObj.setBackground(Color.white);
comboBoxObj.setEnabled(false);
        gbcObj5.anchor=GridBagConstraints.WEST;
gblayoutObj4.setConstraints(comboBoxObj,gbcObj5);
subpanel5.add(labelclass);
subpanel5.add(comboBoxObj);
mainpanel.add(subpanel5);

BorderLayout borLayout=new BorderLayout();
subpanel6.setLayout(borLayout);
labelObj7=new JLabel("显示已注册的学生的所以信息:");
String[][] data=
{
{"张三","20","男","一年级","计算机系"},
{"a2","b2","c2","d2","e2"},
{"a3","b3","c3","d3","e3"},
{"a4","b4","c4","d4","e4"},
{"a5","b5","c5","d5","e5"},
{"李四","19","男","一年级","化学系"},
};
String[] names={"姓名","年龄","性别","年级","系别"};
tableObj=new JTable(data,names);
tableObj.setEnabled(false);
tableObj.setPreferredScrollableViewportSize(new Dimension(240,60));// 设置表格的大小
        ScrollPaneObj=new JScrollPane(tableObj);
subpanel6.add("North",labelObj7);
subpanel6.add("Center",ScrollPaneObj);
mainpanel.add(subpanel6);
FlowLayout fLayout;
fLayout=new FlowLayout(FlowLayout.RIGHT,10,15);
subpanel6.setLayout(fLayout);
        buttonObj1=new JButton("注册(Z)");
buttonObj1.setEnabled(false);
buttonObj2=new JButton("保存(S)");
buttonObj2.setEnabled(false);
    subpanel6.add(buttonObj1);
subpanel6.add(buttonObj2);
mainpanel.add(subpanel6);

gblayoutObj =new GridBagLayout(); 
    gbcObj =new GridBagConstraints();    
        mainpanel.setLayout(gblayoutObj);
gbcObj.gridwidth=GridBagConstraints.REMAINDER;
gbcObj.anchor=GridBagConstraints.NORTHWEST;
gblayoutObj .setConstraints(headlabel,gbcObj);
gbcObj.gridwidth=1;
gblayoutObj .setConstraints(checkBoxObj,gbcObj);
gblayoutObj .setConstraints(subpanel1,gbcObj);
gbcObj.gridwidth=GridBagConstraints.REMAINDER;
gblayoutObj .setConstraints(subpanel2,gbcObj);
gbcObj.gridwidth=1;
        gblayoutObj .setConstraints(subpanel3,gbcObj);
gblayoutObj .setConstraints(subpanel4,gbcObj);
gbcObj.gridwidth=GridBagConstraints.REMAINDER;
gblayoutObj .setConstraints(subpanel5,gbcObj);
gbcObj.gridwidth=GridBagConstraints.REMAINDER;
gblayoutObj .setConstraints(subpanel6,gbcObj);
gbcObj.anchor=GridBagConstraints.NORTHWEST;
gbcObj.gridwidth=GridBagConstraints.REMAINDER;
gblayoutObj .setConstraints(subpanel7,gbcObj);
getContentPane().add(mainpanel);
}
 
}public class j17_6customer 
{
public static void main(String[] args) 
{
new customerTest();
}
} 
帮我看看啊
编译通过但是显示出来的窗口是空的
到底是怎么回事啊
实在不明白啊！！！！