Thread: Using method in Eclipse IDE

Hi, I would like to seek for help because right now I am very confused about why my code is not working..

The function of my code will add records in my database (MySQL), Swing components of my frame..

btnUserAdd = jButton
txtUname, txtPword, txtLname, txtFname, txtMname, txtEmpNo = jTextField
cbAccType = jComboBox
EmpNo, Uname, Pword, Lname, Fname, Mname, AccType = MySQL fields

I created a method to be called when btnUserAdd is clicked. here is the code for the method:

public void UserAdd(){

String sql = "SELECT * FROM User WHERE Uname = ? and EmpNo = ?";

try {

pst = conn.prepareStatement(sql);
pst.setString(1, txtUname.getText().toString());
pst.setString(2, txtEmpNo.getText().toString());
rs = pst.executeQuery();

if (rs.next()){

JOptionPane.showMessageDialog(null, "Record Exists! Please Try Again.");
txtUname.requestFocus();
cbAccType.setSelectedItem("Operator");
UserClear();

}
else {

try {

String sql1 = "INSERT INTO user (EmpNo, Uname, Pword, Lname, Fname, Mname, AccType)" + "VALUES (?, ?, ?, ?, ?, ?, ?)";
String cb1 = cbAccType.getSelectedItem().toString();

pst = conn.prepareStatement(sql1);
pst.setString(1, txtEmpNo.getText());
pst.setString(2, txtUname.getText());
pst.setString(3, txtPword.getText());
pst.setString(4, txtLname.getText());
pst.setString(5, txtFname.getText());
pst.setString(6, txtMname.getText());
pst.setString(7, cb1);
pst.execute();

JOptionPane.showMessageDialog(null, "Record Added!");

}
catch (Exception e){

JOptionPane.showMessageDialog(null, e);

}

}

}
catch (Exception e){

JOptionPane.showMessageDialog(null, e);

}

}

then here is the code inside the btnUserAdd:

btnUserAdd.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent evt) {

if (txtUname.getText().trim().equals("")||txtPword.ge tText().trim().equals("")||txtEmpNo.getText().trim ().equals("")||txtLname.getText().trim().equals("" )){

JOptionPane.showMessageDialog(null, "Please Enter a Username, Password and Employee No, Try Again!");

if (txtUname.getText().trim().equals("")){

txtUname.requestFocus();

}
else if (txtPword.getText().trim().equals("")){

txtPword.requestFocus();

}
else if (txtLname.getText().trim().equals("")){

txtLname.requestFocus();

}
else if (txtEmpNo.getText().trim().equals("")){

txtEmpNo.requestFocus();

}

}
else{

UserAdd();


}

}
});

the error is that it does not add the record it will display JAVA.LANG.NULLPOINTEREXCEPTION...

please help me with my problem..

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Hi, I would like to seek for help because right now I am very confused about why my code is not working..

The function of my code will add records in my database (MySQL), Swing components of my frame..

btnUserAdd = jButton
txtUname, txtPword, txtLname, txtFname, txtMname, txtEmpNo = jTextField
cbAccType = jComboBox
EmpNo, Uname, Pword, Lname, Fname, Mname, AccType = MySQL fields

I created a method to be called when btnUserAdd is clicked. here is the code for the method:

public void UserAdd(){
 
String sql = "SELECT * FROM User WHERE Uname = ? and EmpNo = ?";
 
     try {
 
          pst = conn.prepareStatement(sql);
          pst.setString(1, txtUname.getText().toString());
          pst.setString(2, txtEmpNo.getText().toString());
          rs = pst.executeQuery();
 
               if (rs.next()){
 
                       JOptionPane.showMessageDialog(null, "Record Exists! Please Try Again.");
                       txtUname.requestFocus();
                       cbAccType.setSelectedItem("Operator");
                       UserClear();
 
                }
                else {
 
                        try {
 
                               String sql1 = "INSERT INTO user (EmpNo, Uname, Pword, Lname, Fname, Mname, AccType)" + "VALUES (?, ?, ?, ?, ?, ?, ?)";
                               String cb1 = cbAccType.getSelectedItem().toString();
 
                               pst = conn.prepareStatement(sql1);
                               pst.setString(1, txtEmpNo.getText());
                               pst.setString(2, txtUname.getText());
                               pst.setString(3, txtPword.getText());
                               pst.setString(4, txtLname.getText());
                               pst.setString(5, txtFname.getText());
                               pst.setString(6, txtMname.getText());
                               pst.setString(7, cb1);
                               pst.execute();
 
                               JOptionPane.showMessageDialog(null, "Record Added!");
 
                     }
                     catch (Exception e){
 
                                  JOptionPane.showMessageDialog(null, e);
 
                      }
 
                 }
 
      }
      catch (Exception e){
 
                  JOptionPane.showMessageDialog(null, e);
 
       }
 
}

then here is the code inside the btnUserAdd:

 
btnUserAdd.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent evt) {
 
         if (txtUname.getText().trim().equals("")||txtPword.ge tText().trim().equals("")||txtEmpNo.getText().trim ().equals("")||txtLname.getText().trim().equals("" )){
 
                JOptionPane.showMessageDialog(null, "Please Enter a Username, Password and Employee No, Try Again!");
 
               if (txtUname.getText().trim().equals("")){
 
                      txtUname.requestFocus();
 
               }
              else if (txtPword.getText().trim().equals("")){
 
                      txtPword.requestFocus();
 
               }
              else if (txtLname.getText().trim().equals("")){
 
                      txtLname.requestFocus();
 
               }
              else if (txtEmpNo.getText().trim().equals("")){
 
                      txtEmpNo.requestFocus();
 
               }
 
          }
          else{
 
                UserAdd();	 //method for add
 
 
           }
 
}
});

the problem is that it does not add the record it will display JAVA.LANG.NULLPOINTEREXCEPTION...

please help me with my problem..

Find the variable that is the nullpointer and then backtrack to find out why it is not properly initialized. Then decide how you would want to initialize it with a value properly.

Originally Posted by Cornix

Find the variable that is the nullpointer and then backtrack to find out why it is not properly initialized. Then decide how you would want to initialize it with a value properly.

the catch is I call the method right? when I copy the code inside the method and paste it inside the actionperformed instead of calling the method, IT WORKS!! how is that working? thats my problem..

I will post if I fix this problem thanks by the way