servlets.StudentsServlet.java Source code

Introduction

Here is the source code for servlets.StudentsServlet.java
Source

/*
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 * and open the template in the editor.
 */
package servlets;

import daos.StudentDAO;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.List;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import models.IdCard;
import models.Student;
import org.json.simple.JSONArray;
import org.json.simple.JSONObject;

/**
 *
 * @author GeForce
 */
public class StudentsServlet 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");
        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 StudentsServlet</title>");
            out.println("</head>");
            out.println("<body>");
            out.println("<h1>Servlet StudentsServlet at " + request.getContextPath() + "</h1>");
            out.println("</body>");
            out.println("</html>");
        }
    }

    // <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 {
        try (PrintWriter out = response.getWriter()) {
            try {
                StudentDAO stDao = new StudentDAO();
                List<Student> students = stDao.getAllStudents();
                JSONArray arr = new JSONArray();
                for (Student st : students) {
                    JSONObject obj = new JSONObject();
                    obj.put("id", st.getId());
                    obj.put("name", st.getName());
                    IdCard idCard = st.getIdCard();
                    JSONObject cardObj = new JSONObject();
                    cardObj.put("id", idCard.getId());
                    cardObj.put("idCardNumber", idCard.getIdNumber());
                    obj.put("idCard", cardObj);
                    arr.add(obj);
                }
                arr.writeJSONString(out);
            } catch (Exception e) {
                out.println(e.getMessage());
            }
        }
    }

    /**
     * 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>

}