import java.io.*;
import java.util.*;
import java.sql.*;
import javax.servlet.*;
import javax.servlet.http.*;
 
public class Validation extends HttpServlet{
 
  private ServletConfig config;
 
  public void init(ServletConfig config)
    throws ServletException{
     this.config=config;
 
    // PrintWriter out = response.getWriter();
    String connectionURL = "jdbc:mysql://localhost/test";
    Connection connection=null;
    ResultSet rs;
    String userName=request.getParameter("user"); 
    String password = request.getParameter("pass"); 
 
     //  response.setContentType("text/html");
      try {
             Class.forName("com.mysql.jdbc.Driver");
             connection = DriverManager.getConnection(connectionURL, "root", "password"); 
             String sql = "insert into user values('" + userName  + "','" + password  + "')";
             Statement s = connection.createStatement();
             int x = s.executeUpdate(sql);
             if(x==1)
             {
               System.out.println("<h1> Thanks For the Registration</h1>");  
             } 
           else 
              {
            System.out.println("<h1>+Your Registration is failed..Plase try again+</h1>");  
               } 
          s.close();
 
              }
           catch(Exception e)
            {
          System.out.println("Exception is ;"+e);
            } 
 
}
 
 
  public void service(HttpServletRequest request, HttpServletResponse response) 
  throws ServletException,IOException
   {
 
     PrintWriter out = response.getWriter();
    String connectionURL = "jdbc:mysql://localhost/test";
    Connection connection=null;
    ResultSet rs;
    String userName=new String("");
    String password=new String("");
    response.setContentType("text/html");
 
   try {
      Class.forName("com.mysql.jdbc.Driver");
      connection = DriverManager.getConnection(connectionURL, "root", "password"); 
      String sql = "select user,password from user";
      Statement s = connection.createStatement();
      s.executeQuery (sql);
      rs = s.getResultSet();
      while (rs.next ()){
        userName=rs.getString("user");
        password=rs.getString("password");
      }
      rs.close ();
      s.close ();
      }catch(Exception e){
      System.out.println("Exception is ;"+e);
      }
 
       if(userName.equals(request.getParameter("user")) 
          && password.equals(request.getParameter("pass"))){
        out.println("<h1>User is Valid</h1>");  
 
      }
 
           else 
             {
 
            out.println("<h1>You are not a Valid User</h1>");
            out.println("<a href='myvalidation.jsp'><br>Login again</a>");
              }
   } 
 
  }

Vector userList = new Vector();
User foundUser = null;
while (rs.next()){
   foundUser = new User();
   foundUser.setUserName(rs.getString("user");
   foundUser.setPassword(rs.getString("password");
   userList.add(foundUser);
}
// iterate over the vector, and perform next tests ...
  User testUser = (User)userList.getElementAt((location of the element you want to check));
  if (testUser.getUserName().equalsIgnoreCase(request.getParameter("user")) && testUser.getPassword().equalsIgnoreCase(request.getParameter("password")))
  return true;
 
// end of iteration
return false