Untitled

/*
 * To change this template, choose Tools | Templates
 * and open the template in the editor.
 */


import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.http.*;
//import javax.servlet.http.HttpServletRequest;
//import javax.servlet.http.HttpServletResponse;
import java.sql.*;
import java.util.ArrayList;


/**
 *
 * @author Owner
 */
public class Update_Servlet extends HttpServlet {

    /**
     * Processes requests for both HTTP <code>GET</code> and <code>POST</code> methods.
     * @param request servlet request
     * @param response servlet response
     * @throws ServletException if a servlet-specific error occurs
     * @throws IOException if an I/O error occurs
     */
    protected void processRequest(HttpServletRequest request, HttpServletResponse response)
    throws ServletException, IOException {
        response.setContentType("text/html;charset=UTF-8");
        PrintWriter out = response.getWriter();
        HttpSession mySession = request.getSession();
        ArrayList uNames = (ArrayList)mySession.getAttribute("uNames");
        String UName = request.getParameter("username");
        String PWord = request.getParameter("password");
        String submit = request.getParameter("cmdSubmit");
        String origUName="";
        String error = null;
        boolean update = false;
        if(submit != null) //user clicked submit button
        {
            //retrieve session variable
            origUName = (String) mySession.getAttribute("origUName");
            if(UName.trim().length() > 0 && PWord.trim().length() > 0)
            {
                if(UName.matches("^[A-za-z0-9]+$") && PWord.matches("^[A-Za-z0-9]+$"))
                {

                    if(uNames != null)
                    {
                        if(!UName.equals(origUName))
                        {
                                if(!uNames.contains(UName))
                        {
                            update = true;
                        }
                        else
                        {
                            error = "Primary key violation...("+ UName + ")...Enter new username!";
                        }
                    }
                        else
                        {
                            update = true;
                        }
                    }
                    else
                    {
                        error = "Cookes must be enabled";
                    }
                }

                else
                {
                    //display error message
                    error = "Fields contain invalid characters!.. re enter data!";
                }
            }
            else
            {
                    //display error message
                error = "Fields must be completed!";
            }
        }
        else // if else is true then the page is loaded for the first time...capture original primary key value
        {
            // create session variable
            mySession.setAttribute("origUName", UName);
        }
        if(update)
        {
             String dbURL = "jdbc:odbc:dbJDBC1";
                    String sql = "UPDATE tUsers SET username = '" + UName + "',password ='" + PWord + "' WHERE username = '" + origUName + "'";
                    try
                    {
                          Connection conn = DriverManager.getConnection(dbURL);
                          Statement s = conn.createStatement();
                          s.executeUpdate(sql);
                          s.close();
                          conn.close();
                          response.sendRedirect("Admin_Servlet");
                    }
                    catch(SQLException ex)
                    {
                        error = ex.getMessage();
                    }


        }
        try {

            out.println("<html>");
            out.println("<head>");
            out.println("<title>Servlet Update_Servlet</title>");
            out.println("</head>");
            out.println("<body style = 'font-family: Verdana, Arial, Sans-Serif'>");
            out.println("<h2 align='center'>Update_Servlet</h2>");
            if(error != null)
            {
                out.println("<p align='center' style='color:red'>" + error + "</p>");
            }
            out.println("<form action='Update_Servlet' method='post'>");
            out.println("<table align='center'>");
            out.println("<tr>");
            out.println("<td align='right'>Username:<input type='text' name='username' value='" + UName +"'/><br /></td>");
             out.println("</tr>");
             out.println("<tr>");
            out.println("<td align='right'>Password:<input type='text' name='password' value='" + PWord +"'/><br /></td>");
            out.println("</tr>");
            out.println ("<tr>");
            out.println("<td align='center' colspan='2'><input  type='submit' value='Update Record' name='cmdSubmit' /></td>");
            out.println("</tr>");
            out.println("</table>");
            out.println("</form>");
            out.println("</body>");
            out.println("</html>");

        } finally {
            out.close();
        }
    }

    // <editor-fold defaultstate="collapsed" desc="HttpServlet methods. Click on the + sign on the left to edit the code.">
    /**
     * Handles the HTTP <code>GET</code> method.
     * @param request servlet request
     * @param response servlet response
     * @throws ServletException if a servlet-specific error occurs
     * @throws IOException if an I/O error occurs
     */
    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response)
    throws ServletException, IOException {
        processRequest(request, response);
    }

    /**
     * Handles the HTTP <code>POST</code> method.
     * @param request servlet request
     * @param response servlet response
     * @throws ServletException if a servlet-specific error occurs
     * @throws IOException if an I/O error occurs
     */
    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response)
    throws ServletException, IOException {
        processRequest(request, response);
    }

    /**
     * Returns a short description of the servlet.
     * @return a String containing servlet description
     */
    @Override
    public String getServletInfo() {
        return "Short description";
    }// </editor-fold>

}