HTTP 500 - java.lang.NullPointerException mysql

im trying to finish an application on eclipse using mysql .. this is the problem showen on browser ..

I dont know what does it mean (but i guess the problem is coming from the jar file)

Etat HTTP 500 -

type Rapport d''exception

message

description Le serveur a rencontré une erreur interne qui l''a empêché de satisfaire la requête.

exception

java.lang.NullPointerException
    ma.fsts.miagem2.ebank.model.dao.DAOClient.create(DAOClient.java:12)
    ma.fsts.miagem2.ebank.controler.ServAbonnement.doGet(ServAbonnement.java:48)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:624)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:731)
    org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
note La trace complète de la cause mère de cette erreur est disponible dans les fichiers journaux de Apache Tomcat/7.0.61.

Apache Tomcat/7.0.61

ServAbonnement.java (servlet)

package ma.fsts.miagem2.ebank.controler;

import java.io.IOException;
import java.util.Date;

import javax.servlet.RequestDispatcher;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import ma.fsts.miagem2.ebank.model.bo.Client;
import ma.fsts.miagem2.ebank.model.dao.DAOClient;

/**
 * Servlet implementation class ServAbonnement
 */
@WebServlet("/ServAbonnement")
public class ServAbonnement extends HttpServlet {
    private static final long serialVersionUID = 1L;

    /**
     * @see HttpServlet#HttpServlet()
     */
    public ServAbonnement() {
        super();
        // TODO Auto-generated constructor stub
    }

    /**
     * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
     */
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        // TODO Auto-generated method stub
        boolean resultat=false;
        String cin=request.getParameter("cinh");
        String nom=request.getParameter("nomh");
        String prenom=request.getParameter("prenomh");
        String tele=request.getParameter("teleh");
        String adresse=request.getParameter("adrh");
        String email=request.getParameter("emah");
        String[] d=request.getParameter("datenh").split("-");
        Date datenaiss=new Date(Integer.valueOf(d[0])-1900,Integer.valueOf(d[1])-1,Integer.valueOf(d[2]));

        Client C=new Client(cin,nom,prenom,tele,adresse,email,datenaiss);
        new DAOClient();
        resultat=DAOClient.create(C);
        System.out.println(resultat);
        request.setAttribute("res", resultat);

        RequestDispatcher req=request.getRequestDispatcher("./webpages/Finale.jsp");
        req.forward(request, response);

    }

    /**
     * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
     */
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        // TODO Auto-generated method stub
    }

}

DAOClient.java

package ma.fsts.miagem2.ebank.model.dao;
import java.sql.Date;
import java.sql.SQLException;
import java.util.Collection;
import ma.fsts.miagem2.ebank.model.bo.*;
import java.sql.*;
public class DAOClient {

    public static boolean create(Client C){
        try{

            PreparedStatement pst=Connexion.getCon().prepareStatement("insert into client values(?,?,?,?,?,?,?)");
            pst.clearParameters();
            pst.setString(1,C.cin);
            pst.setString(2,C.nom);
            pst.setString(3,C.prenom);
            pst.setString(4,C.tele);
            pst.setString(5,C.adresse);
            pst.setString(6,C.email);
            String m=String.valueOf(C.datenaissance.getMonth()+1);
            String j=String.valueOf(C.datenaissance.getDate());
            String a=String.valueOf(C.datenaissance.getYear()+1900);
            String dd=a+'-'+m+'-'+j;
            pst.setString(7, dd);
            pst.executeUpdate();

            return true;
        }
        catch(SQLException e){
            e.printStackTrace();
            return false;
        }


    }
    public static boolean update(Client C){return true;}
    public static boolean delete(Client C){return true;}
    public static Collection<Client> retreive(){return null;}
}