Why code can compiled successfully without mysql-connector-java-#-bin.jar installed

[cy163 hotmail com]

Hello All, In my program, i want to use a Java servlet to response to users' web request, in which the info submitted by users is write into a remote MySQL database. To this end, I have to establish a connection to the MySQL database firsts. I do this using the following code and can compile it sucessfully. It is strange to me that the code can be compiled successfully,though there is actually not mysql-connector-java-###-bin.jar package installed/copied on the Linux box.

import java.sql.*;
import java.io.*;
import java.util.*;
public class welcomeyou extends HttpServlet
{
public void doGet(HttpServletRequest rqu, HttpServletResponse resp)
{
String driver="com.mysql.jdbc.Driver";
String url="jdbc:mysql://192.168.1.1/DatabaseName";
String databaseuser="root";
String password=""
Connection con = null;Statement smt =null;
Resultset rs=null;
try
{

             con=DriverManager.getConnection(url, databaseuser, password);
             smt =con.createStatement();
      }
     catch(SQLException E)
      {
          System.out.println("SQLException:" + E.getMessage());
         System.exit(0);
       }

}
}

I cannot provide error message, since the statement System.out.println("....) could not display error message on the screen in this circumstance.(Could anybody tell me how to do this ) I wonder if the statement 'import java.sql.*;' means import library from mysql-connector-java-###-bin.jar Please help me, this problem has stuck me for a long time. thanks