java代码出现异常，空指针

package view;import java.awt.BorderLayout;
import java.awt.EventQueue;import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.border.EmptyBorder;
import javax.swing.JLabel;
import java.awt.Font;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.SQLException;
import java.sql.Statement;import javax.swing.JTextField;
import javax.swing.JButton;
import util.*;public class AddStuView extends JFrame { private JPanel contentPane;
private JTextField stuidField;
private JTextField stunameField;
private JTextField sexField;
private JTextField snativeField;
private JTextField phoneField;
private JTextField classField;
private JTextField gradeField;
private JTextField majorField;
private JTextField collegeField;
 
private Connection con = null;
private Statement stmt = null;
  //  private PreparedStatement pstmt = null;
/**
 * Launch the application.
 */
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
public void run() {
try {
AddStuView frame = new AddStuView();
frame.setVisible(true);
} catch (Exception e) {
e.printStackTrace();
}
}
});
} /**
 * Create the frame.
 */
public AddStuView() {
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setBounds(100, 100, 450, 320);
contentPane = new JPanel();
contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));
setContentPane(contentPane);
contentPane.setLayout(null);

JLabel label = new JLabel("\u6DFB\u52A0\u5B66\u751F\u4FE1\u606F");
label.setFont(new Font("宋体", Font.PLAIN, 18));
label.setBounds(177, 10, 113, 36);
contentPane.add(label);

JLabel label_1 = new JLabel("\u5B66 \u53F7 \uFF1A");
label_1.setBounds(27, 60, 54, 15);
contentPane.add(label_1);

stuidField = new JTextField();
stuidField.setBounds(78, 57, 121, 21);
contentPane.add(stuidField);
stuidField.setColumns(10);

JLabel label_2 = new JLabel("\u59D3 \u540D \uFF1A");
label_2.setBounds(27, 96, 54, 15);
contentPane.add(label_2);

stunameField = new JTextField();
stunameField.setColumns(10);
stunameField.setBounds(78, 93, 121, 21);
contentPane.add(stunameField);

JLabel label_3 = new JLabel("\u6027 \u522B \uFF1A");
label_3.setBounds(27, 134, 54, 15);
contentPane.add(label_3);

sexField = new JTextField();
sexField.setColumns(10);
sexField.setBounds(78, 131, 121, 21);
contentPane.add(sexField);

JLabel label_4 = new JLabel("\u7C4D \u8D2F \uFF1A");
label_4.setBounds(27, 169, 54, 15);
contentPane.add(label_4);

snativeField = new JTextField();
snativeField.setColumns(10);
snativeField.setBounds(78, 166, 121, 21);
contentPane.add(snativeField);

JLabel label_5 = new JLabel("\u7535 \u8BDD \uFF1A");
label_5.setBounds(27, 201, 54, 15);
contentPane.add(label_5);

phoneField = new JTextField();
phoneField.setColumns(10);
phoneField.setBounds(78, 198, 121, 21);
contentPane.add(phoneField);

JLabel label_6 = new JLabel("\u73ED \u7EA7 \uFF1A");
label_6.setBounds(231, 56, 54, 15);
contentPane.add(label_6);

classField = new JTextField();
classField.setColumns(10);
classField.setBounds(286, 56, 121, 21);
contentPane.add(classField);

JLabel label_7 = new JLabel("\u5E74 \u7EA7 \uFF1A");
label_7.setBounds(231, 96, 54, 15);
contentPane.add(label_7);

gradeField = new JTextField();
gradeField.setColumns(10);
gradeField.setBounds(286, 93, 121, 21);
contentPane.add(gradeField);

JLabel label_8 = new JLabel("\u4E13 \u4E1A \uFF1A");
label_8.setBounds(231, 134, 54, 15);
contentPane.add(label_8);

majorField = new JTextField();
majorField.setColumns(10);
majorField.setBounds(286, 131, 121, 21);
contentPane.add(majorField);

JLabel label_9 = new JLabel("\u5B66 \u9662 \uFF1A");
label_9.setBounds(231, 169, 54, 15);
contentPane.add(label_9);

collegeField = new JTextField();
collegeField.setColumns(10);
collegeField.setBounds(286, 166, 121, 21);
contentPane.add(collegeField);

JButton savebutton1 = new JButton("\u4FDD\u5B58");
savebutton1.setBounds(192, 249, 93, 23);
contentPane.add(savebutton1);

//为savebutton1添加监听器
savebutton1.addActionListener(b1);
}
//为savebutton1创建监听器
   private ActionListener b1  =  new ActionListener(){ public void actionPerformed(ActionEvent e) {
// TODO Auto-generated method stub
con = CommonaJdbc.conection;
String sql = "insert into student values('"+stuidField.getText()
                             +"','"+stunameField.getText()
                             +"','"+sexField.getText()
                             +"','"+snativeField.getText()
                             +"','"+phoneField.getText()
                             +"','"+classField.getText()
                             +"','"+gradeField.getText()
                             +"','"+majorField.getText()
                             +"','"+collegeField.getText()
                             +
                             "')";
try {
stmt.executeUpdate(sql);
} catch (SQLException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}

}
   
   };
} 
Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
at view.AddStuView$1.actionPerformed(AddStuView.java:176)
at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:2018)
at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2341)
at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:402)
at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:259)
at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(BasicButtonListener.java:252)
at java.awt.Component.processMouseEvent(Component.java:6505)
at javax.swing.JComponent.processMouseEvent(JComponent.java:3321)
at java.awt.Component.processEvent(Component.java:6270)
at java.awt.Container.processEvent(Container.java:2229)
at java.awt.Component.dispatchEventImpl(Component.java:4861)
at java.awt.Container.dispatchEventImpl(Container.java:2287)
at java.awt.Component.dispatchEvent(Component.java:4687)
这代码出现这种异常，请问各位，这个应该怎么改才行啊？我想了很久都没有想出来

解决方案 »

  1.   

    但我加了这个之后，还是出现这个问题：
    try {
    stmt = con.createStatement();
    } catch (SQLException e2) {
    // TODO Auto-generated catch block
    e2.printStackTrace();
    }
      

  2.   

    con = CommonaJdbc.conection ？？
    是不是打错字了？？
      

  3.   


    这一行的内容是什么？
    at view.AddStuView$1.actionPerformed(AddStuView.java:176)
    at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:2018)
    at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2341)
    at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:402)
    at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:259)
    at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(BasicButtonListener.java:252)
    at java.awt.Component.processMouseEvent(Component.java:6505)
    at javax.swing.JComponent.processMouseEvent(JComponent.java:3321)
    at java.awt.Component.processEvent(Component.java:6270)
    at java.awt.Container.processEvent(Container.java:2229)
    at java.awt.Component.dispatchEventImpl(Component.java:4861)
    at java.awt.Container.dispatchEventImpl(Container.java:2287)
    at java.awt.Component.dispatchEvent(Component.java:4687)
    at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4832)
    at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4492)
    at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4422)
    at java.awt.Container.dispatchEventImpl(Container.java:2273)
    at java.awt.Window.dispatchEventImpl(Window.java:2719)
    at java.awt.Component.dispatchEvent(Component.java:4687)
    at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:729)
    at java.awt.EventQueue.access$200(EventQueue.java:103)
    at java.awt.EventQueue$3.run(EventQueue.java:688)
    at java.awt.EventQueue$3.run(EventQueue.java:686)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
    at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:87)
    at java.awt.EventQueue$4.run(EventQueue.java:702)
    at java.awt.EventQueue$4.run(EventQueue.java:700)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
    at java.awt.EventQueue.dispatchEvent(EventQueue.java:699)
    at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:242)
    at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:161)
    at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:150)
    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:146)
    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:138)
    at java.awt.EventDispatchThread.run(EventDispatchThread.java:91)
      

  4.   

    你的private Statement stmt = null;这么定义的，然后直接用了，当然会空指针。
    stmt = con.createStatement();
    stmt.executeUpdate(sql);这样如果还有错的话，请把新的错误和代码贴上来，谢谢
      

  5.   


    package view;import java.awt.BorderLayout;
    import java.awt.EventQueue;import javax.swing.JFrame;
    import javax.swing.JPanel;
    import javax.swing.border.EmptyBorder;
    import javax.swing.JLabel;
    import java.awt.Font;
    import java.awt.event.ActionEvent;
    import java.awt.event.ActionListener;
    import java.sql.Connection;
    import java.sql.PreparedStatement;
    import java.sql.SQLException;
    import java.sql.Statement;import javax.swing.JTextField;
    import javax.swing.JButton;
    import util.*;public class AddStuView extends JFrame { private JPanel contentPane;
    private JTextField stuidField;
    private JTextField stunameField;
    private JTextField sexField;
    private JTextField snativeField;
    private JTextField phoneField;
    private JTextField classField;
    private JTextField gradeField;
    private JTextField majorField;
    private JTextField collegeField;
     
    public Connection con = null;
    public Statement stmt = null;
      //  private PreparedStatement pstmt = null;
    /**
     * Launch the application.
     */
    public static void main(String[] args) {
    EventQueue.invokeLater(new Runnable() {
    public void run() {
    try {
    AddStuView frame = new AddStuView();
    frame.setVisible(true);
    } catch (Exception e) {
    e.printStackTrace();
    }
    }
    });
    } /**
     * Create the frame.
     * @throws SQLException 
     */
    public AddStuView() throws SQLException {
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    setBounds(100, 100, 450, 320);
    contentPane = new JPanel();
    contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));
    setContentPane(contentPane);
    contentPane.setLayout(null);

    JLabel label = new JLabel("\u6DFB\u52A0\u5B66\u751F\u4FE1\u606F");
    label.setFont(new Font("宋体", Font.PLAIN, 18));
    label.setBounds(177, 10, 113, 36);
    contentPane.add(label);

    JLabel label_1 = new JLabel("\u5B66 \u53F7 \uFF1A");
    label_1.setBounds(27, 60, 54, 15);
    contentPane.add(label_1);

    stuidField = new JTextField();
    stuidField.setBounds(78, 57, 121, 21);
    contentPane.add(stuidField);
    stuidField.setColumns(10);

    JLabel label_2 = new JLabel("\u59D3 \u540D \uFF1A");
    label_2.setBounds(27, 96, 54, 15);
    contentPane.add(label_2);

    stunameField = new JTextField();
    stunameField.setColumns(10);
    stunameField.setBounds(78, 93, 121, 21);
    contentPane.add(stunameField);

    JLabel label_3 = new JLabel("\u6027 \u522B \uFF1A");
    label_3.setBounds(27, 134, 54, 15);
    contentPane.add(label_3);

    sexField = new JTextField();
    sexField.setColumns(10);
    sexField.setBounds(78, 131, 121, 21);
    contentPane.add(sexField);

    JLabel label_4 = new JLabel("\u7C4D \u8D2F \uFF1A");
    label_4.setBounds(27, 169, 54, 15);
    contentPane.add(label_4);

    snativeField = new JTextField();
    snativeField.setColumns(10);
    snativeField.setBounds(78, 166, 121, 21);
    contentPane.add(snativeField);

    JLabel label_5 = new JLabel("\u7535 \u8BDD \uFF1A");
    label_5.setBounds(27, 201, 54, 15);
    contentPane.add(label_5);

    phoneField = new JTextField();
    phoneField.setColumns(10);
    phoneField.setBounds(78, 198, 121, 21);
    contentPane.add(phoneField);

    JLabel label_6 = new JLabel("\u73ED \u7EA7 \uFF1A");
    label_6.setBounds(231, 56, 54, 15);
    contentPane.add(label_6);

    classField = new JTextField();
    classField.setColumns(10);
    classField.setBounds(286, 56, 121, 21);
    contentPane.add(classField);

    JLabel label_7 = new JLabel("\u5E74 \u7EA7 \uFF1A");
    label_7.setBounds(231, 96, 54, 15);
    contentPane.add(label_7);

    gradeField = new JTextField();
    gradeField.setColumns(10);
    gradeField.setBounds(286, 93, 121, 21);
    contentPane.add(gradeField);

    JLabel label_8 = new JLabel("\u4E13 \u4E1A \uFF1A");
    label_8.setBounds(231, 134, 54, 15);
    contentPane.add(label_8);

    majorField = new JTextField();
    majorField.setColumns(10);
    majorField.setBounds(286, 131, 121, 21);
    contentPane.add(majorField);

    JLabel label_9 = new JLabel("\u5B66 \u9662 \uFF1A");
    label_9.setBounds(231, 169, 54, 15);
    contentPane.add(label_9);

    collegeField = new JTextField();
    collegeField.setColumns(10);
    collegeField.setBounds(286, 166, 121, 21);
    contentPane.add(collegeField);

    JButton savebutton1 = new JButton("\u4FDD\u5B58");
    savebutton1.setBounds(192, 249, 93, 23);
    contentPane.add(savebutton1);

    //为savebutton1添加监听器
    savebutton1.addActionListener(b1);

    }
    //为savebutton1创建监听器
       private ActionListener b1  =  new ActionListener(){ public void actionPerformed(ActionEvent e) {
    // TODO Auto-generated method stub
    con = CommonaJdbc.conection;
    String sql = "insert into student values('"+stuidField.getText()
                                 +"','"+stunameField.getText()
                                 +"','"+sexField.getText()
                                 +"','"+snativeField.getText()
                                 +"','"+phoneField.getText()
                                 +"','"+classField.getText()
                                 +"','"+gradeField.getText()
                                 +"','"+majorField.getText()
                                 +"','"+collegeField.getText()
                                 +
                                 "')";

    try {
    stmt = con.createStatement();
    } catch (SQLException e2) {
    // TODO Auto-generated catch block
    e2.printStackTrace();
    }
    try {
    stmt.executeUpdate(sql);
    } catch (SQLException e1) {
    // TODO Auto-generated catch block
    e1.printStackTrace();
    }

    }
       
       };
    }现在我已经初始化
     stmt = con.createStatement();
    但还是出错，同样的异常！
      

  6.   

    Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
    at view.AddStuView$1.actionPerformed(AddStuView.java:179)
    at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:2018)
    at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2341)
    at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:402)
    at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:259)
    at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(BasicButtonListener.java:252)
    at java.awt.Component.processMouseEvent(Component.java:6505)
    at javax.swing.JComponent.processMouseEvent(JComponent.java:3321)
    at java.awt.Component.processEvent(Component.java:6270)
    at java.awt.Container.processEvent(Container.java:2229)
    at java.awt.Component.dispatchEventImpl(Component.java:4861)
    at java.awt.Container.dispatchEventImpl(Container.java:2287)
    at java.awt.Component.dispatchEvent(Component.java:4687)
    at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4832)
    at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4492)
    at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4422)
    at java.awt.Container.dispatchEventImpl(Container.java:2273)
    at java.awt.Window.dispatchEventImpl(Window.java:2719)
    at java.awt.Component.dispatchEvent(Component.java:4687)
    at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:729)
    at java.awt.EventQueue.access$200(EventQueue.java:103)
    at java.awt.EventQueue$3.run(EventQueue.java:688)
    at java.awt.EventQueue$3.run(EventQueue.java:686)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
    at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:87)
    at java.awt.EventQueue$4.run(EventQueue.java:702)
    at java.awt.EventQueue$4.run(EventQueue.java:700)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
    at java.awt.EventQueue.dispatchEvent(EventQueue.java:699)
    at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:242)
    at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:161)
    at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:150)
    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:146)
    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:138)
    at java.awt.EventDispatchThread.run(EventDispatchThread.java:91)
      

  7.   

    异常也许都是NullPoint，但是地方可能不一样了，你把新的异常贴出来看看。另外，确认下con = CommonaJdbc.conection;是否有问题。最好把CommonaJdbc也贴出来看看
      

  8.   


    这是新的异常：
    Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
    at view.AddStuView$1.actionPerformed(AddStuView.java:179)
    at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:2018)
    at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2341)
    at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:402)
    at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:259)
    at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(BasicButtonListener.java:252)
    at java.awt.Component.processMouseEvent(Component.java:6505)
    at javax.swing.JComponent.processMouseEvent(JComponent.java:3321)
    at java.awt.Component.processEvent(Component.java:6270)
    at java.awt.Container.processEvent(Container.java:2229)
    at java.awt.Component.dispatchEventImpl(Component.java:4861)
    at java.awt.Container.dispatchEventImpl(Container.java:2287)
    at java.awt.Component.dispatchEvent(Component.java:4687)
    at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4832)
    at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4492)
    at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4422)
    at java.awt.Container.dispatchEventImpl(Container.java:2273)
    at java.awt.Window.dispatchEventImpl(Window.java:2719)
    at java.awt.Component.dispatchEvent(Component.java:4687)
    at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:729)
    at java.awt.EventQueue.access$200(EventQueue.java:103)
    at java.awt.EventQueue$3.run(EventQueue.java:688)
    at java.awt.EventQueue$3.run(EventQueue.java:686)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
    at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:87)
    at java.awt.EventQueue$4.run(EventQueue.java:702)
    at java.awt.EventQueue$4.run(EventQueue.java:700)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
    at java.awt.EventQueue.dispatchEvent(EventQueue.java:699)
    at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:242)
    at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:161)
    at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:150)
    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:146)
    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:138)
    at java.awt.EventDispatchThread.run(EventDispatchThread.java:91)我
    我看了很久都不知道哪里出错啊！
      

  9.   


    这是新的异常：
    Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
    at view.AddStuView$1.actionPerformed(AddStuView.java:179)
    at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:2018)
    at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2341)
    at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:402)
    at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:259)
    at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(BasicButtonListener.java:252)
    at java.awt.Component.processMouseEvent(Component.java:6505)
    at javax.swing.JComponent.processMouseEvent(JComponent.java:3321)
    at java.awt.Component.processEvent(Component.java:6270)
    at java.awt.Container.processEvent(Container.java:2229)
    at java.awt.Component.dispatchEventImpl(Component.java:4861)
    at java.awt.Container.dispatchEventImpl(Container.java:2287)
    at java.awt.Component.dispatchEvent(Component.java:4687)
    at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4832)
    at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4492)
    at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4422)
    at java.awt.Container.dispatchEventImpl(Container.java:2273)
    at java.awt.Window.dispatchEventImpl(Window.java:2719)
    at java.awt.Component.dispatchEvent(Component.java:4687)
    at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:729)
    at java.awt.EventQueue.access$200(EventQueue.java:103)
    at java.awt.EventQueue$3.run(EventQueue.java:688)
    at java.awt.EventQueue$3.run(EventQueue.java:686)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
    at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:87)
    at java.awt.EventQueue$4.run(EventQueue.java:702)
    at java.awt.EventQueue$4.run(EventQueue.java:700)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
    at java.awt.EventQueue.dispatchEvent(EventQueue.java:699)
    at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:242)
    at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:161)
    at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:150)
    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:146)
    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:138)
    at java.awt.EventDispatchThread.run(EventDispatchThread.java:91)我
    我看了很久都不知道哪里出错啊！错误在AddStuView.java:179行，是不是con调用的返回是null啊？把conn的操作代码发出来看看那？
      

  10.   

    问题出在这一段
    public void actionPerformed(ActionEvent e) {
    // TODO Auto-generated method stub
    con = CommonaJdbc.conection;
    String sql = "insert into student values('"+stuidField.getText()
                                 +"','"+stunameField.getText()
                                 +"','"+sexField.getText()
                                 +"','"+snativeField.getText()
                                 +"','"+phoneField.getText()
                                 +"','"+classField.getText()
                                 +"','"+gradeField.getText()
                                 +"','"+majorField.getText()
                                 +"','"+collegeField.getText()
                                 +
                                 "')";
    try {at view.AddStuView$1.actionPerformed(AddStuView.java:179) at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:2018) at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2341) at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:402)
      

  11.   

    嗯，这个有没有解决的办法？你是怎么实现connection的？