JDBC: My Sql Insert Statement

package mysqlconnect;

import java.sql.*; 
class Insert{ 
public static void main(String args[]) throws SQLException, ClassNotFoundException{ 
   
Class.forName("com.mysql.jdbc.Driver"); 
Connection con=DriverManager.getConnection( 
"jdbc:mysql://db4fre.net/sumit1234","sumit1234","sumit1234"); 
//here db4fre.net/sumit1234 is server/database name, sumit1234 username and sumit1234password 
Statement stmt=con.createStatement(); 
String begin = "INSERT INTO `test`(`firstname`, `lastname`) VALUES ";

for (int i = 2000; i < 3001; i++) {

begin = begin + "(" + i + "," + (i + 10) + ")" + ",";
}

begin = begin.replaceAll(",$", ";"); //As we want ; after last value
stmt.executeUpdate(begin); //INSERT DELTE UPDATE needs executeUpdate
   
con.close(); 

} 

}