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.aankam.servlet; import com.mongodb.BasicDBObject; import com.mongodb.DB; import com.mongodb.DBCollection; import com.mongodb.DBCursor; import com.mongodb.DBObject; import com.mongodb.MongoClient; import com.mongodb.MongoClientURI; import java.io.IOException; import java.io.PrintWriter; import javax.servlet.ServletException; import javax.servlet.annotation.WebServlet; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; /** * * @author aankam */ @WebServlet(name = "MongoCrudServlet", urlPatterns = { "/MongoCrudServlet" }) public class MongoCrudServlet 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 { MongoClientURI uri = new MongoClientURI("mongodb://Username:Pasword@ds061721.mongolab.com:61721/cs612"); MongoClient client = new MongoClient(uri); DB db = client.getDB(uri.getDatabase()); response.setContentType("text/html;charset=UTF-8"); String serialNo = request.getParameter("serialNo"); String name = request.getParameter("name"); String emailId = request.getParameter("emailId"); String operation = request.getParameter("operation"); BasicDBObject customer; BasicDBObject updateQuery; BasicDBObject deleteQuery; BasicDBObject searchQuery; DBCollection customersCollection; customersCollection = db.getCollection("Customers"); DBObject searchResult = null; boolean flag = false; DBCursor cursor; switch (operation) { case "create": customer = new BasicDBObject(); customer.put("serialNo", serialNo); customer.put("name", name); customer.put("emailId", emailId); customersCollection.insert(customer); break; case "update": updateQuery = new BasicDBObject(); updateQuery.append("serialNo", serialNo); cursor = customersCollection.find(updateQuery); customer = new BasicDBObject(); customer.put("serialNo", serialNo); customer.put("name", name); customer.put("emailId", emailId); if (cursor.hasNext()) { customersCollection.update(updateQuery, customer); flag = true; } break; case "delete": deleteQuery = new BasicDBObject(); deleteQuery.append("serialNo", serialNo); customersCollection.remove(deleteQuery); break; case "search": searchQuery = new BasicDBObject(); searchQuery.append("serialNo", serialNo); cursor = customersCollection.find(searchQuery); while (cursor.hasNext()) { searchResult = cursor.next(); } break; default: break; } 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 MongoCrudServlet</title>"); out.println("</head>"); out.println("<body>"); switch (operation) { case "create": out.println("<h3>Customer was successfully created.</h3>"); break; case "update": if (flag == true) { out.println("<h3>Customer was successfully updated.</h3>"); } else { out.println("<h3>Customer was not found to update.</h3>"); } break; case "delete": out.println("<h3>Customer was successfully deleted.</h3>"); break; case "search": if (searchResult != null) { out.println("<h3>The following customer was found:</h3>"); out.println("<h4>Serial No :" + searchResult.get("serialNo") + "</h4>"); out.println("<h4>Name :" + searchResult.get("name") + "</h4>"); out.println("<h4>Email Id :" + searchResult.get("emailId") + "</h4>"); } else { out.println("<h3>Customer not found.</h3>"); } break; default: break; } out.println("<a href=\"index.html\">Back to Main Form</a>"); 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 { 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> }