State_Servlet.java Source code

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/*
 * To change this license header, choose License Headers in Project Properties.
 * To change this template file, choose Tools | Templates
 * and open the template in the editor.
 */

import com.google.gson.Gson;
import java.io.IOException;
import java.io.PrintWriter;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 *
 * @author Vaibhav
 */
public class State_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) {
        response.setContentType("text/html;charset=UTF-8");
        try (PrintWriter out = response.getWriter()) {

            /* TODO output your page here. You may use following sample code. */

            /*  out.println("<!DOCTYPE html>");
              out.println("<html>");
              out.println("<head>");
              out.println("<title>Servlet java</title>");            
              out.println("</head>");
              out.println("<body>");
              out.println("<h1>Servlet java at " + request.getContextPath() + "</h1>");
              out.println("</body>");
              out.println("</html*/
            try {
                String JDBC_driver = "com.mysql.jdbc.Driver";
                String DB_URL = "jdbc:mysql://localhost:3306/wheels_on_rent";
                Class.forName(JDBC_driver);
                String db_user = "root";
                String db_pass = "";

                Connection conn = DriverManager.getConnection(DB_URL, db_user, db_pass);
                String query = "SELECT DISTINCT `State/Union Territory` FROM `india_states_cities` ";
                PreparedStatement pst = conn.prepareStatement(query);
                ResultSet rs = pst.executeQuery();

                String json;
                ArrayList<State> listStates = new ArrayList<State>();
                while (rs.next()) {
                    State s = new State();
                    s.setState_name(rs.getString("State/Union Territory"));
                    listStates.add(s);
                    //s.setCity_name(rs.getString("City"));

                }
                Gson g = new Gson();

                json = g.toJson(listStates);
                out.print(json);

                rs.close();
                pst.close();
                conn.close();
            } catch (Exception ex) {
                out.print("error" + ex.getMessage());
            }
        } catch (IOException ex) {
            Logger.getLogger(State_Servlet.class.getName()).log(Level.SEVERE, null, ex);
        }

    }

    // <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>

}