1git clone https://github.com/gitorko/project87
2cd project87
3docker-compose -f docker/docker-compose.yml up 

  1package com.demo.project87.controller;
  2
  3import java.io.ByteArrayOutputStream;
  4import java.io.IOException;
  5import java.net.InetAddress;
  6import java.time.LocalDateTime;
  7import java.util.HashSet;
  8import java.util.Set;
  9import java.util.UUID;
 10import javax.transaction.Transactional;
 11
 12import com.demo.project87.domain.BookingRequest;
 13import com.demo.project87.domain.Ticket;
 14import com.demo.project87.repository.TicketRepository;
 15import com.google.zxing.BarcodeFormat;
 16import com.google.zxing.WriterException;
 17import com.google.zxing.client.j2se.MatrixToImageWriter;
 18import com.google.zxing.common.BitMatrix;
 19import com.google.zxing.qrcode.QRCodeWriter;
 20import lombok.RequiredArgsConstructor;
 21import lombok.extern.slf4j.Slf4j;
 22import org.springframework.beans.factory.annotation.Autowired;
 23import org.springframework.http.MediaType;
 24import org.springframework.orm.ObjectOptimisticLockingFailureException;
 25import org.springframework.scheduling.annotation.Scheduled;
 26import org.springframework.web.bind.annotation.GetMapping;
 27import org.springframework.web.bind.annotation.PathVariable;
 28import org.springframework.web.bind.annotation.PostMapping;
 29import org.springframework.web.bind.annotation.RequestBody;
 30import org.springframework.web.bind.annotation.ResponseBody;
 31import org.springframework.web.bind.annotation.RestController;
 32
 33@RestController
 34@Slf4j
 35@RequiredArgsConstructor
 36public class HomeController {
 37
 38    private static final Integer EXPIRY_TTL_SECS = 30;
 39
 40    @Autowired
 41    TicketRepository ticketRepo;
 42
 43    @GetMapping(value = "/api/user")
 44    public String getUser() {
 45        return UUID.randomUUID().toString().substring(0, 7);
 46    }
 47
 48    @GetMapping(value = "/api/tickets")
 49    public Iterable<Ticket> getTickets() {
 50        return ticketRepo.findAllByOrderByIdAsc();
 51    }
 52
 53    @PostMapping(value = "/api/ticket")
 54    public Boolean bookTicket(@RequestBody BookingRequest bookingRequest) {
 55        log.info("Confirming Booking! {}", bookingRequest);
 56        return confirmBooking(bookingRequest);
 57    }
 58
 59    @PostMapping(value = "/api/hold")
 60    public Boolean holdBooking(@RequestBody BookingRequest bookingRequest) {
 61        log.info("Holding booking tickets! {}", bookingRequest);
 62        return bookingHoldCall(bookingRequest, true);
 63    }
 64
 65    @PostMapping(value = "/api/cancel")
 66    public Boolean cancelBooking(@RequestBody BookingRequest bookingRequest) {
 67        log.info("Cancelling booking tickets! {}", bookingRequest);
 68        return bookingHoldCall(bookingRequest, false);
 69    }
 70
 71    @GetMapping(value = "/api/admit/{entryToken}")
 72    public String admit(@PathVariable String entryToken) {
 73        Ticket ticket = ticketRepo.findByEntryTokenIs(entryToken);
 74        if (ticketRepo.findByEntryTokenIs(entryToken) != null) {
 75            ticket.setEntered(true);
 76            ticketRepo.save(ticket);
 77            return "ADMIT";
 78        } else {
 79            return "INVALID";
 80        }
 81    }
 82
 83    @GetMapping(value = "/api/qrcode/{entryToken}", produces = MediaType.IMAGE_JPEG_VALUE)
 84    public @ResponseBody byte[] getQRCode(@PathVariable String entryToken) {
 85        Ticket ticket = ticketRepo.findByEntryTokenIs(entryToken);
 86        if (ticketRepo.findByEntryTokenIs(entryToken) != null) {
 87            return ticket.getQrCode();
 88        } else {
 89            return null;
 90        }
 91    }
 92
 93    @Transactional
 94    public Boolean confirmBooking(BookingRequest bookingRequest) {
 95        try {
 96            Iterable<Ticket> ticketSet = ticketRepo.findAllById(bookingRequest.getTicketIds());
 97            Set<Ticket> tickets = new HashSet<>();
 98            for (Ticket ticket : ticketSet) {
 99                tickets.add(ticket);
100                //Only person who held the lock can complete the booking.
101                if (ticket.getLockedBy().equals(bookingRequest.getUser())) {
102                    ticket.setLockedBy("");
103                    ticket.setBooked(true);
104                    ticket.setBookedBy(bookingRequest.getUser());
105
106                    //Create the QR code for the ticket and store to DB.
107                    String entryToken = UUID.randomUUID().toString();
108                    ticket.setEntryToken(entryToken);
109                    String hostName = InetAddress.getLocalHost().getHostAddress();
110                    String entryUri = "http://" + hostName + ":8080/api/admit/" + entryToken;
111                    QRCodeWriter qrCodeWriter = new QRCodeWriter();
112                    BitMatrix bitMatrix = qrCodeWriter.encode(entryUri, BarcodeFormat.QR_CODE, 200, 200);
113                    try (ByteArrayOutputStream baos = new ByteArrayOutputStream()) {
114                        MatrixToImageWriter.writeToStream(bitMatrix, "PNG", baos);
115                        byte[] png = baos.toByteArray();
116                        ticket.setQrCode(png);
117                    }
118
119                } else {
120                    log.info("Ticket: {} lock is held by other user!", ticket);
121                    return false;
122                }
123            }
124            ticketRepo.saveAll(tickets);
125            return true;
126        } catch (ObjectOptimisticLockingFailureException ex) {
127            log.error("Booking confirmation failed due to lock, {}", ex.getMessage());
128            return false;
129        } catch (WriterException | IOException ex) {
130            log.error("Failed to generate QR code, {}", ex.getMessage());
131            return false;
132        } catch (Exception ex) {
133            log.error("Booking confirmation failed, {}", ex.getMessage());
134            return false;
135        }
136
137    }
138
139    @Transactional
140    public Boolean bookingHoldCall(BookingRequest bookingRequest, Boolean start) {
141        try {
142            Iterable<Ticket> ticketSet = ticketRepo.findAllById(bookingRequest.getTicketIds());
143            Set<Ticket> tickets = new HashSet<>();
144            for (Ticket ticket : ticketSet) {
145                tickets.add(ticket);
146                //Reserve the ticket till the time payment is done.
147                if (start) {
148                    if (ticket.getBooked()) {
149                        log.info("Ticket: {} is already booked!", ticket);
150                        return false;
151                    }
152                    //Only if ticket is free it can be booked.
153                    if (ticket.getLockedBy().equals("")) {
154                        ticket.setLockedBy(bookingRequest.getUser());
155                        //TTL to release lock after 30 seconds.
156                        ticket.setLockExpiry(LocalDateTime.now().plusSeconds(EXPIRY_TTL_SECS));
157                        log.info("Ticket: {} is reserved!", ticket);
158                    } else {
159                        log.info("Ticket: {} is already locked by other user!", ticket);
160                        return false;
161                    }
162                } else {
163                    //Only person who held the lock can release it.
164                    if (ticket.getLockedBy().equals(bookingRequest.getUser())) {
165                        ticket.setLockedBy("");
166                        log.info("Ticket: {} is released!", ticket);
167                    } else {
168                        log.info("Ticket: {} is already locked by other user!", ticket);
169                        return false;
170                    }
171                }
172            }
173            ticketRepo.saveAll(tickets);
174            return true;
175        } catch (ObjectOptimisticLockingFailureException ex) {
176            log.error("Error reserving flow: {}", ex.getMessage());
177            return false;
178        }
179
180    }
181
182    //Runs every 1 min.
183    @Scheduled(fixedRate = 60000)
184    public void scheduleFixedRateTask() {
185        log.info("Running lock cleanup job!");
186        Iterable<Ticket> ticketSet = ticketRepo.findAllByLockExpiryIsNotNull();
187        Set<Ticket> tickets = new HashSet<>();
188        ticketSet.forEach(t -> {
189            if (t.getLockExpiry().isBefore(LocalDateTime.now())) {
190                t.setLockedBy("");
191                t.setLockExpiry(null);
192                ticketRepo.save(t);
193                log.info("Ticket: {} lock released!", t);
194            }
195        });
196        log.info("Lock cleanup job completed!");
197    }
198
199}

 1import {Injectable} from '@angular/core';
 2import {HttpClient} from '@angular/common/http';
 3import {Observable} from 'rxjs';
 4import {Ticket} from '../models/ticket';
 5import {BookingRequest} from '../models/booking-request';
 6
 7@Injectable({
 8  providedIn: 'root'
 9})
10export class RestService {
11
12  constructor(private http: HttpClient) {
13  }
14
15  public getTickets(): Observable<Ticket[]> {
16    return this.http.get<Ticket[]>('/api/tickets');
17  }
18
19  public bookTicket(bookingRequest: BookingRequest): Observable<any> {
20    return this.http.post('/api/ticket', bookingRequest);
21  }
22
23  public holdBooking(bookingRequest: BookingRequest): Observable<any> {
24    return this.http.post('/api/hold', bookingRequest);
25  }
26
27  public cancelBooking(bookingRequest: BookingRequest): Observable<any> {
28    return this.http.post('/api/cancel', bookingRequest);
29  }
30
31  public getUser(): Observable<string> {
32    return this.http.get<string>('/api/user', {responseType: 'text' as 'json'});
33  }
34
35}

 1<div class="content-container">
 2  <div class="content-area">
 3    <div class="clr-row">
 4      <div class="clr-col-12">
 5        <div class="alert-section">
 6          <app-alert></app-alert>
 7        </div>
 8        <h2 style="text-align: center">Tickets</h2>
 9        <clr-datagrid [(clrDgSelected)]="selected">
10          <clr-dg-column [clrDgField]="'seatNumber'">Seat Number</clr-dg-column>
11          <clr-dg-column [clrDgField]="'eventDate'">Date</clr-dg-column>
12          <clr-dg-column [clrDgField]="'price'">Price</clr-dg-column>
13          <clr-dg-column [clrDgField]="'booked'">Status</clr-dg-column>
14          <clr-dg-column [clrDgField]="'bookedBy'">Booked By</clr-dg-column>
15          <clr-dg-column>QR Code</clr-dg-column>
16          <clr-dg-column [clrDgField]="'entered'">Entered</clr-dg-column>
17          <!-- structural directive -->
18          <clr-dg-row clr-dg-row *clrDgItems="let ticket of tickets" [clrDgItem]="ticket"
19                      [clrDgSelectable]="getSeatStatus(ticket) === 'AVAILABLE'">
20            <clr-dg-placeholder class="content-center">No Tickets!</clr-dg-placeholder>
21            <clr-dg-cell>{{ticket.seatNumber}}</clr-dg-cell>
22            <clr-dg-cell>{{ticket.eventDate}}</clr-dg-cell>
23            <clr-dg-cell>{{ticket.price}}</clr-dg-cell>
24            <clr-dg-cell>{{getSeatStatus(ticket)}}</clr-dg-cell>
25            <clr-dg-cell>{{ticket.bookedBy}}</clr-dg-cell>
26            <clr-dg-cell >
27              <a *ngIf="getSeatStatus(ticket) === 'BOOKED'" href="/api/qrcode/{{ticket.entryToken}}"
28                 target="_blank">Ticket</a>
29            </clr-dg-cell>
30            <clr-dg-cell>
31              <cds-icon *ngIf="ticket.entered" shape="success-standard" status="success" title="Admitted"
32                        class="action-icon" solid></cds-icon>
33            </clr-dg-cell>
34          </clr-dg-row>
35
36          <clr-dg-footer>
37            <clr-dg-pagination #pagination [clrDgPageSize]="10">
38              <clr-dg-page-size [clrPageSizeOptions]="[10,20,50,100]">Tickets per page</clr-dg-page-size>
39              {{pagination.firstItem + 1}} - {{pagination.lastItem + 1}} of {{pagination.totalItems}} tickets
40            </clr-dg-pagination>
41          </clr-dg-footer>
42        </clr-datagrid>
43        <br/>
44        <button type="submit" class="btn btn-primary btn-block" (click)="holdBooking()"
45                *ngIf="selected.length > 0">Book
46          Ticket
47        </button>
48      </div>
49    </div>
50  </div>
51</div>
52
53<!--Pay Modal-->
54<clr-modal [(clrModalOpen)]="payModal" [clrModalClosable]="false">
55  <h3 class="modal-title">Pay & Confirm</h3>
56  <div class="modal-body">
57    <p>You have 30 Secs to complete the payment!</p>
58    <p *ngFor="let item of selected;index as i">{{i + 1}}. {{item.seatNumber}}</p>
59    <p>Total Amount: {{getTotal()}} Rs.</p>
60  </div>
61  <div class="modal-footer">
62    <button type="button" class="btn btn-outline" (click)="cancelBooking()">Cancel</button>
63    <button type="button" class="btn btn-primary" (click)="confirmBooking()">Confirm</button>
64  </div>
65</clr-modal>

  1import {Component, OnInit, ViewChild} from '@angular/core';
  2import {Ticket} from '../../models/ticket';
  3import {RestService} from '../../services/rest.service';
  4import {Router} from '@angular/router';
  5import {ClarityIcons, trashIcon} from '@cds/core/icon';
  6import {AlertComponent} from '../alert/alert.component';
  7import {BookingRequest} from '../../models/booking-request';
  8
  9@Component({
 10  selector: 'app-home',
 11  templateUrl: './home.component.html',
 12  styleUrls: []
 13})
 14export class HomeComponent implements OnInit {
 15
 16  tickets: Ticket[] = [];
 17  ticket: Ticket = new Ticket();
 18  selected: Ticket[] = [];
 19  // @ts-ignore
 20  @ViewChild(AlertComponent, {static: true}) private alert: AlertComponent;
 21  payModal = false;
 22
 23  constructor(private restService: RestService, private router: Router) {
 24    ClarityIcons.addIcons(trashIcon);
 25  }
 26
 27  ngOnInit(): void {
 28    this.getTickets();
 29  }
 30
 31  getTickets(): void {
 32    this.ticket = new Ticket();
 33    this.restService.getTickets().subscribe(data => {
 34      this.tickets = data;
 35    });
 36  }
 37
 38  holdBooking(): void {
 39    const request = new BookingRequest();
 40    request.ticketIds = [];
 41    request.user = sessionStorage.getItem('user');
 42    this.selected.forEach(item => {
 43      request.ticketIds.push(Number(item.id));
 44    });
 45    this.restService.holdBooking(request)
 46      .subscribe(data => {
 47          if (data) {
 48            this.payModal = true;
 49          } else {
 50            this.alert.showError('Ticket is already reserved, Try again!');
 51            this.getTickets();
 52          }
 53        },
 54        error => {
 55          this.alert.showError('Ticket is already reserved, Try again!');
 56          this.getTickets();
 57        });
 58
 59  }
 60
 61  cancelBooking(): void {
 62    const request = new BookingRequest();
 63    request.ticketIds = [];
 64    request.user = sessionStorage.getItem('user');
 65    this.selected.forEach(item => {
 66      request.ticketIds.push(Number(item.id));
 67    });
 68    this.restService.cancelBooking(request)
 69      .subscribe(data => {
 70        this.payModal = false;
 71      });
 72  }
 73
 74  confirmBooking(): void {
 75    const request = new BookingRequest();
 76    request.ticketIds = [];
 77    request.user = sessionStorage.getItem('user');
 78    this.selected.forEach(item => {
 79      request.ticketIds.push(Number(item.id));
 80    });
 81    this.restService.bookTicket(request)
 82      .subscribe(data => {
 83        if (data) {
 84          this.alert.showSuccess('Ticket booked successfully!');
 85        } else {
 86          this.alert.showError('Ticket booking failed!');
 87        }
 88        this.payModal = false;
 89        this.getTickets();
 90      });
 91  }
 92
 93  getTotal(): number {
 94    let sum = 0;
 95    this.selected.forEach(item => {
 96      // @ts-ignore
 97      sum += item.price;
 98    });
 99    return sum;
100  }
101
102  getSeatStatus(ticket: Ticket): string {
103    // @ts-ignore
104    if (ticket.lockedBy !== '') {
105      return 'RESERVED';
106    }
107    if (ticket.booked) {
108      return 'BOOKED';
109    } else {
110      return 'AVAILABLE';
111    }
112  }
113
114}

1$java --version
2openjdk 17.0.3 2022-04-19 LTS
3
4node --version
5v16.16.0
6
7yarn --version
81.22.18

1docker run -p 5432:5432 --name pg-container -e POSTGRES_PASSWORD=password -d postgres:9.6.10
2docker ps
3docker exec -it pg-container psql -U postgres -W postgres
4CREATE USER test WITH PASSWORD 'test@123';
5CREATE DATABASE "test-db" WITH OWNER "test" ENCODING UTF8 TEMPLATE template0;
6grant all PRIVILEGES ON DATABASE "test-db" to test;
7
8docker stop pg-container
9docker start pg-container

1./gradlew clean build
2./gradlew bootRun

1cd ui
2yarn install
3yarn build
4yarn start

1./gradlew cleanBuild
2cd build/libs
3java -jar project87-1.0.0.jar

1./gradlew cleanBuild
2docker build -f docker/Dockerfile --force-rm -t project87:1.0.0 .
3docker images |grep project87
4docker tag project87:1.0.0 gitorko/project87:1.0.0
5docker push gitorko/project87:1.0.0
6docker-compose -f docker/docker-compose.yml up