Connection error while connecting wamp server with netbeans8.1 - connection

Question

I can't get any output from this program. Do you know why? I am using NetBeans 8.1 and wamp server. I design database named assignments online. Can you also suggest if I am using true drivers?
package managmentSystem;
import javax.swing.*;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.Statement;
import java.sql.SQLException;
/**
*
* #author DiyaBangesh
*/
public class ManagmentSystem {
//PreparedStatement pst = null;
//Statement st= null;
/**
* #param args the command line arguments
*/
public static void main(String args[]) {
try{
ResultSet rs;
Connection conn;
Class.forName("com.mysql.jdbc.Driver");
conn = DriverManager.getConnection("jdbc:mysql://localhost/assignment","root","");
JOptionPane.showMessageDialog(null,"Connection to database is established");
//return conn;
Statement st = conn.createStatement();
String sql ="SELECT * FROM userdetails";
rs = st.executeQuery(sql);
while(rs.next()){
String nam = rs.getString("name");
String uid = rs.getString("user_id");
String pwd = rs.getString("password");
String eid = rs.getString("email_id");
String con = rs.getString("contact");
String ut = rs.getString("usertype");
System.out.println(nam + " " + uid + " " + pwd + " "+ eid + " " + con + " " + ut );
}
conn.close();
}
catch (Exception sqlEx){
System.out.println(sqlEx);
}
}
}

Answer 1

mysql-connector-java-bin.jar is the one needeed and you have already used it. Make sure that you used correct database name & correct password. Replace 'yourpassword' with your database password. And make sure that server is running.
Follow as below.
public class ManagmentSystem {
Connection con;
Statement s;
PreparedStatement ps;
ResultSet rs;
ManagmentSystem()
{
try
{ Class.forName("com.mysql.jdbc.Driver");
con=DriverManager.getConnection("jdbc:mysql://localhost/assignment?user=root&password=yourpassword");
}
catch(SQLException s)
{
System.out.println("Error in DB Connection");
s.printStackTrace();
}
catch(ClassNotFoundException c)
{
System.out.println("Driver not Found");
}
}
}