"int cannot be dereferenced" error is at k=PIE.gcd(e1)

Question

 import java.io.*;
 import javax.servlet.*;
 import javax.servlet.ServletException;   
 import javax.servlet.http.*;  
 import java.sql.*;
 import java.math.*;
 public class Servlet3 extends HttpServlet {

  protected void doGet(HttpServletRequest request, HttpServletResponse response)
        throws ServletException, IOException {
    response.setContentType("text/html;charset=UTF-8");
    PrintWriter out = response.getWriter();

    String U_ID = request.getParameter("USER_ID");
    int user_id=Integer.valueOf(U_ID);
    String Bank_name = request.getParameter("bankname"); 
    String nom = request.getParameter("NOM");

    String acc_num = request.getParameter("Acc_num");
    int ACC_NUM=Integer.valueOf(acc_num);

    String PIN = request.getParameter("pin");
    int Pin=Integer.valueOf(PIN);

    String DOB = request.getParameter("dob"); 
    String P_VALUE=request.getParameter("p");
    int P_PRIME=Integer.valueOf(P_VALUE);
    String Q_VALUE=request.getParameter("q");
    int Q_PRIME=Integer.valueOf(Q_VALUE);
    int n=P_PRIME*Q_PRIME;
    int PIE=(P_PRIME-1)*(Q_PRIME-1);
    int e1,d,k=0;
    for(e1=1;e1<PIE;e1=e1+1)
    {
      k=PIE.gcd(e1);
      if(k==1)
        break;
    }
    out.println("<b> e value="+e1); 
    for(d=1;d<PIE;d++)
    {
      int m=(e1*d)%PIE;
      if(m==1)
        break;
        }      
    }  
  }

Answer 1

You declared PIE as integer, you need to use BigInteger to invoke gcd(..)