/*
* To change this template, choose Tools | Templates
* and open the template in the editor.
*/
package mobileAPI;
import entity.Courses;
import entity.Enrollment;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import jpa.controllers.CoursesJpaController;
import jpa.controllers.EnrollmentJpaController;
import net.sf.json.JSONArray;
import net.sf.json.JSONObject;
/**
*
* @author Geymen
*/
public class MyCoursesListServlet 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
*/
public void processRequest(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setContentType("text/html;charset=UTF-8");
PrintWriter out = response.getWriter();
Integer userID;
userID = Integer.valueOf(request.getParameter("userID"));
// First get enrollment entities which matches with userID
EnrollmentJpaController enrollmentJpaController = new EnrollmentJpaController();
List<Enrollment> enrollmentList = enrollmentJpaController.findEnrollmentEntitiesWithUserID(userID);
//********************************
// Second generate a list of courseIDs
List<Integer> courseIDList = new ArrayList<Integer>();
for (Iterator<Enrollment> it = enrollmentList.iterator(); it.hasNext();) {
Enrollment enrollment = it.next();
courseIDList.add(enrollment.getCourseId().getCourseId());
}
//********************************
// Third generate a array list with maps containing courseIDs and their descriptions
CoursesJpaController coursesJpaController = new CoursesJpaController();
ArrayList coursesMapList = new ArrayList();
for (Iterator<Integer> it = courseIDList.iterator(); it.hasNext();) {
Integer courseID = it.next();
Courses course = coursesJpaController.findCourses(courseID);
Map courseMap = new HashMap();
courseMap.put("courseID", new Integer(courseID));
courseMap.put("courseName", new String(course.getName()));
coursesMapList.add(courseMap);
}
//********************************
// Forth generate a JSONObject object containts JSONArray
JSONArray coursesListJSONArray = JSONArray.fromObject(coursesMapList);
JSONObject respondJSONObject = new JSONObject();
respondJSONObject.element("myCoursesList", coursesListJSONArray);
try {
/* 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 MyCoursesListServlet</title>");
// out.println("</head>");
// out.println("<body>");
// out.println("<h1>Servlet MyCoursesListServlet at " + request.getContextPath() + "</h1>");
// out.println("</body>");
// out.println("</html>");
out.println(respondJSONObject);
} 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>
}