异常信息:
Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
at clientcommunication.ConnectSever.Sendmessage(ConnectSever.java:52)
at clientinterface.Register.actionPerformed(Register.java:115)
at javax.swing.AbstractButton.fireActionPerformed(Unknown Source)
at javax.swing.AbstractButton$Handler.actionPerformed(Unknown Source)
at javax.swing.DefaultButtonModel.fireActionPerformed(Unknown Source)
at javax.swing.DefaultButtonModel.setPressed(Unknown Source)
clientinterface.Register.actionPerformed(Register.java:115)类:
public class Register extends JFrame implements ActionListener { /**
*
*/
private static final long serialVersionUID = 1L;
private JPanel contentPane;
private JTextField textField;
private JTextField textField_1;
private JTextField textField_2;
private JTextField textField_3;
private JLabel label_4;
private JPasswordField passwordField;
private JPasswordField passwordField_1;
private JButton button;
private JButton button_1; /**
* Create the frame.
*/
public Register() {
//
} @Override
public void actionPerformed(ActionEvent e) {
if (e.getSource() == button)
{
ConnectSever.Sendmessage("注册");
//ConnectSever.Sendmessage("注册");
//String RM=ClientDataconvercheck.checkregister(textField.getText(), textField_1.getText(), textField_2.getText(), textField_3.getText(), passwordField.getPassword(), passwordField_1.getPassword());
//ConnectSever.Sendmessage(RM);
}else if(e.getSource() == button_1)
{
this.dispose();
}
}
}clientcommunication.ConnectSever.Sendmessage(ConnectSever.java:52)[/ /**
* 发送消息
* @param message
*/
public static void Sendmessage(String message)
{
try {
Output.writeUTF(message);
} catch (IOException e) {
e.printStackTrace();
}
}
想知道的:
问题具体是什么(最好是指出位置,给予说明 方便其他人);
怎么产生的;
该怎么解决;
更不懂得是 在其他类似地方尽然不会出错。
Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
at clientcommunication.ConnectSever.Sendmessage(ConnectSever.java:52)
at clientinterface.Register.actionPerformed(Register.java:115)
at javax.swing.AbstractButton.fireActionPerformed(Unknown Source)
at javax.swing.AbstractButton$Handler.actionPerformed(Unknown Source)
at javax.swing.DefaultButtonModel.fireActionPerformed(Unknown Source)
at javax.swing.DefaultButtonModel.setPressed(Unknown Source)
clientinterface.Register.actionPerformed(Register.java:115)类:
public class Register extends JFrame implements ActionListener { /**
*
*/
private static final long serialVersionUID = 1L;
private JPanel contentPane;
private JTextField textField;
private JTextField textField_1;
private JTextField textField_2;
private JTextField textField_3;
private JLabel label_4;
private JPasswordField passwordField;
private JPasswordField passwordField_1;
private JButton button;
private JButton button_1; /**
* Create the frame.
*/
public Register() {
//
} @Override
public void actionPerformed(ActionEvent e) {
if (e.getSource() == button)
{
ConnectSever.Sendmessage("注册");
//ConnectSever.Sendmessage("注册");
//String RM=ClientDataconvercheck.checkregister(textField.getText(), textField_1.getText(), textField_2.getText(), textField_3.getText(), passwordField.getPassword(), passwordField_1.getPassword());
//ConnectSever.Sendmessage(RM);
}else if(e.getSource() == button_1)
{
this.dispose();
}
}
}clientcommunication.ConnectSever.Sendmessage(ConnectSever.java:52)[/ /**
* 发送消息
* @param message
*/
public static void Sendmessage(String message)
{
try {
Output.writeUTF(message);
} catch (IOException e) {
e.printStackTrace();
}
}
想知道的:
问题具体是什么(最好是指出位置,给予说明 方便其他人);
怎么产生的;
该怎么解决;
更不懂得是 在其他类似地方尽然不会出错。
【code=Java】
【/code】
方括号换成 阿司克码 里的 []就有格式了 你这乱的,一看就不想看咯
当你进行的是查询操作,当然返回值为null,所以会抛异常,查询的时候应该用execute方法。
执行数据库完数据库操作完成后,要关闭连接。