NullPointerException on statement.executeUpdate()

Question

I created a website with JSP and Java, it simply displays a form (it's a user registration form) where the user can fill it, then I want it to be stored in a database. I installed Eclipse, Tomcat (to host on localhost 8080) and Wampserver (to have phpmyadmin and my SQL database).

I've tried to create an ORM (Object-relational mapping), so when the client submits the form, it sends the datas to my ORM, my ORM then stores the datas in my database.

The issue is, when the user submit submits the form, my table is created (I can see it on phpmyAdmin), so it's very good. But it crashes on my website and creates an error

HTTP500, java.lang.NullPointerException.

It says the problem is on

com.jweb.bdd.Orm.Perform(Orm.java:139)

Here is my code in my CreateClient.java file, this java file handles the servlet of my registration form:

  public class CreationClient extends HttpServlet {
      public void doGet( HttpServletRequest request, HttpServletResponse response ) throws ServletException, IOException {

        [...]
        String lastName= request.getParameter( CHAMP_LASTNAME);
        String Name= request.getParameter( CHAMP_NAME);
        String mailAdress = request.getParameter( CHAMP_MAILADRESS);
        String phoneNumber= request.getParameter( CHAMP_PHONENUMBER);
        String login= request.getParameter( CHAMP_LOGIN);
        [...]

         Orm orm = new Orm();
         String[] field = {"login", "firstName", "lastName", "mailAdress", "adress", "phoneNumber", "password"};
         String[] values = {login, firstName, lastName, mailAdress, adress, phoneNumber, password};
         orm.Insert("client", field);
         orm.Values(values);
         orm.Perform();
         orm.CloseConnection();

         [...]
    }
}

Here is my Perfom() function in my ORM class:

public void Perform(){
            ResultSet rst = null;

            if (select != null){
                    if (from != null && where != null){
                            try {          
                                    rst = statement.executeQuery(select + from + where);
                            } catch (SQLException e) {
                                    // TODO Auto-generated catch block
                                    e.printStackTrace();
                            }
                            try {
                                    int i = 0;
                                    while (rst.next()){
                                    res[i] = rst.getString(0) + ":" + rst.getString(1)+ ":" + rst.getString(3) + ":" + rst.getString(4) +":" + rst.getString(5) + ":" + rst.getString(6)+ ":" + rst.getString(7) + ";";
                                    i++;
                                    }
                            } catch (SQLException e){
                                    e.printStackTrace();
                            }
                    }
            }
            else if (insert != null){
                    if (values != null){
                            try {
                             // statement = connexion.creatStatemnt();
                                    int res = statement.executeUpdate(insert + values);
                            } catch (SQLException e) {
                                    e.printStackTrace();
                            }
                    }
            }
            try {
                    rst.close();
            } catch (SQLException ignore){         
            }
            if ( statement != null ) {
        try {
            statement.close();
        } catch ( SQLException ignore ) {
        }
    }
    }

And the error on the line 139 is the int res = statement.executeUpdate(insert + values); :

   else if (insert != null){
                        if (values != null){
                                try {
                                        int res = statement.executeUpdate(insert + values);
                                } catch (SQLException e) {
                                        e.printStackTrace();
                                }
                        }

Do you have any idea how to fix this issue of NullPointer?

Thanks.

The thing to remember is this error is caused by the `.` operator when the left side is `null`. Like, you can't call `null.executeUpdate()`. — developerwjk, Jan 06 '15 at 17:30

score 4 · Accepted Answer · answered Jan 06 '15 at 17:25

4

You need to initialize your statement object, In your code you used statement.executeQuery() but not statement = connection.createStatement() initialize statement object.

answered Jan 06 '15 at 17:25

atish shimpi

4,873
2
32
50

NullPointerException on statement.executeUpdate()

1 Answers1