Null Pointer Exception while executeUpdate for a query using JDBC

Question

I am getting a Null Pointer Exception while executing the insert query. Everything seems to be fine but the problem still exists.

Code used for Database Connection.

public class DBConnect 
{
    static Connection c ;
    static Statement st ;
    {
        try 
        {
            Class.forName("oracle.jdbc.driver.OracleDriver");
            c=DriverManager.getConnection("jdbc:oracle:thin:@localhost:1521:xe","ashuthesmartest","ashutosha");
            st=c.createStatement();
        } 
        catch (Exception ex) 
        {
            JOptionPane.showMessageDialog(null, "Database error");
        }
    }   
}

Action Performed on Button Click

private void b3ActionPerformed(java.awt.event.ActionEvent evt) {                                   
    try 
    {
        char[] arr = pa1.getPassword() ;
        String s2 = Arrays.toString(arr) ;
        String s1 = t3.getText() ;
        DBConnect.st.executeUpdate("insert into LOGIN values('"+s1+"','"+s2+"')");   **//EXCEPTION IN THIS LINE**
    } 
    catch (Exception ex) 
    {
        ex.printStackTrace();
    }
} 

Answer 1

The initialization block in which you create the connection and the statement is not a static initialization block.

Therefore, it will only be executed when you create an instance of the class DBConnect.

Since you seem to be using DBConnect only statically, that never happens. Your initialization block should be made static. A static initialization block has the keyword static preceding the left brace:

static {
    // try etc.
}