Java tutorial
/* * 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. */ package com.bios.controller.services; import com.bios.controller.BiddingRoundServlet; import com.bios.model.Bid; import com.bios.model.BidDAO; import com.bios.model.CourseDAO; import com.bios.model.MinBidDAO; import com.bios.model.SectionDAO; import com.bios.model.Student; import com.bios.model.StudentDAO; import com.bios.utilities.BidComparator; import com.bios.utilities.ConnectionManager; import com.bios.utilities.ErrorMsgComparator; import com.google.gson.JsonArray; import com.google.gson.JsonElement; import com.google.gson.JsonObject; import com.google.gson.JsonParser; import com.google.gson.JsonPrimitive; import is203.JWTException; import is203.JWTUtility; import java.io.IOException; import java.io.PrintWriter; import java.util.ArrayList; import java.util.Collections; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; /** * Represents a JSON Web Service for Delete Bid * @author Marc */ public class DeleteBidService extends HttpServlet { // <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 and deletes the bid. It retrieves the userID, courseID, section ID, and amount bidded to verify the bid. * Upon verification, the bid will be deleted from bidDAO and database. Upon successful deletion, a json object is created with the * status "success". If the bid deletion is unsuccessful, a json object with the status "error" is created together with a * json array of the errors that caused the unsuccessful deletion. * * @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 { ConnectionManager manager = new ConnectionManager(); String requestObject = request.getParameter("r"); String token = request.getParameter("token"); ArrayList<String> errorList = new ArrayList<String>(); JsonObject responseObject = new JsonObject(); JsonArray allErrors = new JsonArray(); if (requestObject == null) { errorList.add("missing r"); } else if (requestObject.length() == 0) { errorList.add("blank r"); } if (token == null) { errorList.add("missing token"); } else if (token.length() == 0) { errorList.add("blank token"); } else { try { String result = JWTUtility.verify(token, "abcdefgh12345678"); if (!result.equals("admin")) { errorList.add("invalid token"); } } catch (JWTException e) { // do we need this? // This means not an admin, or token expired errorList.add("invalid username/token"); } } JsonElement jelementRequest = new JsonParser().parse(requestObject); JsonObject json = jelementRequest.getAsJsonObject(); JsonElement crse = json.get("course"); JsonElement sec = json.get("section"); JsonElement user = json.get("userid"); if (crse == null) { errorList.add("missing course"); } else if (crse.getAsString().length() == 0) { errorList.add("blank course"); } if (sec == null) { errorList.add("missing section"); } else if (sec.getAsString().length() == 0) { errorList.add("blank section"); } if (user == null) { errorList.add("missing userid"); } else if (user.getAsString().length() == 0) { errorList.add("blank userid"); } if (errorList.size() > 0) { errorList.sort(new ErrorMsgComparator()); for (String s : errorList) { allErrors.add(new JsonPrimitive(s)); } responseObject.addProperty("status", "error"); responseObject.add("message", allErrors); response.setContentType("application/json"); response.getWriter().write(responseObject.toString()); return; } String courseID = crse.getAsString(); String sectionID = sec.getAsString(); String userID = user.getAsString(); BidDAO bidDAO = BidDAO.getInstance(); CourseDAO courseDAO = CourseDAO.getInstance(); SectionDAO sectionDAO = SectionDAO.getInstance(); StudentDAO studentDAO = StudentDAO.getInstance(); String roundStatus = manager.getBiddingRoundStatus(); Bid bid = bidDAO.getBid(userID, courseID, sectionID); if (roundStatus.equals("stopped") || !bidDAO.deleteBid(userID, courseID, sectionID)) { responseObject.addProperty("status", "error"); if (courseDAO.findCourse(courseID) == null) { allErrors.add(new JsonPrimitive("invalid course")); } if (sectionDAO.findSection(courseID, sectionID) == null) { allErrors.add(new JsonPrimitive("invalid section")); } if (studentDAO.findStudent(userID) == null) { allErrors.add(new JsonPrimitive("invalid userid")); } if (roundStatus.equals("stopped")) { allErrors.add(new JsonPrimitive("round ended")); } if (roundStatus.equals("started") && allErrors.size() == 0) { allErrors.add(new JsonPrimitive("no such bid")); } responseObject.add("message", allErrors); response.setContentType("application/json"); response.getWriter().write(responseObject.toString()); return; } else { // no errors detected in the deletion of bids MinBidDAO.getInstance().getMinBidList().remove(courseID + "-" + sectionID); MinBidDAO.getInstance().refresh(); responseObject.addProperty("status", "success"); Student stud = studentDAO.retrieve(userID); stud.seteDollar(stud.geteDollar() + bid.getAmount()); manager.refundEDollar(userID, bid.getAmount()); bidDAO.deleteBidFromDB(userID, courseID, sectionID); } response.setContentType("application/json"); response.getWriter().write(responseObject.toString()); } /** * 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 { } /** * Returns a short description of the servlet. * * @return a String containing servlet description */ @Override public String getServletInfo() { return "Short description"; }// </editor-fold> }