Database connection in Java Servlet

Question

I'm trying to connect to a database in a Java Servlet, but I am unable to connect. I searched on google and each website is showing different way I don't know why.

Here is the code that I tried to connect, but nothing(data) is going to MySQL database rows.

public class DBConnection{
    private static final long serialVersionUID = 1L;

    private final Connection connection;
    private final String dbURL = "jdbc:mysql://localhost:3306/Servlet";
    private final String user = "root";
    private final String pwd = "";
    public DBConnection() throws ClassNotFoundException, SQLException{
        Class.forName("com.mysql.jdbc.Driver");
        this.connection = DriverManager.getConnection(dbURL, user, pwd);
    }

    public Connection gC(){
        return this.connection;
    }
}

Here is I'm trying to insert data in database (but data is not adding to DB).

public class ReServlet extends HttpServlet {
    private static final long serialVersionUID = 1L;
    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse res)
            throws ServletException, IOException {
        try{
            String uName=req.getParameter("uName");
            String uEmail=req.getParameter("uEmail");
            String uPass=req.getParameter("uPass");
            DBConnection conn=new DBConnection();
            PreparedStatement ps;
            ps = conn.gC().prepareStatement("insert into users(name,email,password) values (?,?,?)");
            ps.setString(1, uName);
            ps.setString(2, uEmail);
            ps.setString(3, uPass);
            ps.execute();
        }catch(SQLException | ClassNotFoundException se){
           se.printStackTrace();

        }finally{
        } 
    }
}

I also request to all, please give me simple and easy database connection example, about each website is showing with full registration or any other system. But I just want simple db connection example as I am trying in my code.

Edited By replacing se.printStackTrace(); to this throw new RuntimeException(se); I'm getting this Exception java.lang.RuntimeException: java.lang.ClassNotFoundException: com.mysql.jdbc.Driver

Why `DBConection` extends `HTTPServlet`? You get any exceptions? — Jens, Oct 18 '15 at 07:48
@Jens Sorry, I was trying different way, and forget to remove that. Where I can see exception? there is nothing during compile time. — Asif Mushtaq, Oct 18 '15 at 07:52
@Jens Sorry I'm new to Servlet, I'm using netbeans and GlassFish, where I can see? In which folder? — Asif Mushtaq, Oct 18 '15 at 07:55
For debugging only, you might want to consider replacing `se.printStackTrace()` with `throw new RuntimeException(se)` so the exception is displayed in the browser. Most likely reason btw is the fact your password is empty. — Mark Rotteveel, Oct 18 '15 at 08:01
@MarkRotteveel there is no password, I'm using default password. — Asif Mushtaq, Oct 18 '15 at 08:03
i am not working with netbeans and glassfish so i can not say where the logs are. Maybe it is in the console or you can ask google. — Jens, Oct 18 '15 at 08:06
@Jens by using Mark method, I got this Exception. `java.lang.RuntimeException: java.lang.ClassNotFoundException: com.mysql.jdbc.Driver` now what to do? — Asif Mushtaq, Oct 18 '15 at 08:07
You should also check if mysql is running and the database must exists — Jens, Oct 18 '15 at 08:07
For logs (you will need them): http://stackoverflow.com/questions/13835913/location-of-glassfish-server-logs — PeterMmm, Oct 18 '15 at 08:07
You may set `Connection.setAutocommit(true)` to get out of doubts. — PeterMmm, Oct 18 '15 at 08:10
@PeterMmm where to add? I'm getting this Exception `java.lang.RuntimeException: java.lang.ClassNotFoundException: com.mysql.jdbc.Driver` — Asif Mushtaq, Oct 18 '15 at 08:11

score -1 · Answer 1 · answered Oct 18 '15 at 08:08

-1

You nedd to register your driver with DriverManager like this:

   Class c = Class.forName("com.mysql.jdbc.Driver");
   DriverManager.registerDriver( c.newInstance() );

Please remember to close your connection in finally block.

answered Oct 18 '15 at 08:08

k0staa

319
2
5

I think it could solve my Problem but where to add these lines? – Asif Mushtaq Oct 18 '15 at 08:10
In your DBConnection constructor. – k0staa Oct 18 '15 at 08:18

Database connection in Java Servlet

1 Answers1