BAEL-9307: cqrs with spring modulith (#18700)

* BAEL-9307: code samples

* BAEL-9307: docker compose

* BAEL-9307: repackage

* BAEL-9307: minor refactoring

* BAEL-9307: repackage

* BAEL-9307: remove sysout

* BAEL-9307: changes

* BAEL-9307: pom changes and table schema

* BAEL-9307: simplify

* BAEL-9307: version param

* BAEL-9307: extract method

* BAEL-9307: code review

* BAEL-9307: code review

* BAEL-9307: simplify

* BAEL-9307: code review

* BAEL-9307: upgrade lib versions

Author: etrandafir93

spring-boot-modules/spring-boot-libraries-3/pom.xml

@@ -64,6 +64,17 @@
             <version>${spring-modulith.version}</version>
             <scope>test</scope>
         </dependency>
+        <dependency>
+            <groupId>org.springframework.modulith</groupId>
+            <artifactId>spring-modulith-core</artifactId>
+            <version>${spring-modulith.version}</version>
+        </dependency>
+
+        <dependency>
+            <groupId>org.jmolecules</groupId>
+            <artifactId>jmolecules-cqrs-architecture</artifactId>
+            <version>${jmolecules-cqrs-architecture.version}</version>
+        </dependency>
 
         <dependency>
             <groupId>org.springframework.boot</groupId>
@@ -123,19 +134,36 @@
             <artifactId>jolokia-support-spring</artifactId>
             <version>${jolokia-support-spring.version}</version>
         </dependency>
+        <dependency>
+            <groupId>ch.qos.logback</groupId>
+            <artifactId>logback-classic</artifactId>
+            <version>${logback-core.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>ch.qos.logback</groupId>
+            <artifactId>logback-core</artifactId>
+            <version>${logback-core.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>net.logstash.logback</groupId>
+            <artifactId>logstash-logback-encoder</artifactId>
+            <version>8.1</version>
+        </dependency>
     </dependencies>
 
 
     <properties>
-        <spring-boot.version>3.1.5</spring-boot.version>
-        <spring-modulith.version>1.1.3</spring-modulith.version>
+        <spring-boot.version>3.5.4</spring-boot.version>
+        <spring-modulith.version>1.4.2</spring-modulith.version>
         <testcontainers.version>1.19.3</testcontainers.version>
         <awaitility.version>4.2.0</awaitility.version>
         <postgresql.version>42.3.1</postgresql.version>
         <h2.version>2.2.224</h2.version>
         <jolokia-support-spring.version>2.2.1</jolokia-support-spring.version>
         <eventuate.tram.version>0.36.0.RELEASE</eventuate.tram.version>
         <json-unit-assertj.version>3.5.0</json-unit-assertj.version>
+        <jmolecules-cqrs-architecture.version>1.10.0</jmolecules-cqrs-architecture.version>
+        <logback-core.version>1.5.18</logback-core.version>
     </properties>
 
     <build>

spring-boot-modules/spring-boot-libraries-3/src/main/java/com/baeldung/Application.java

@@ -4,13 +4,13 @@
 import org.springframework.boot.autoconfigure.SpringBootApplication;
 
 /**
- * use the appropriate profile: eventuate|modulith
+ * use the appropriate profile: eventuate|modulith|cqrs
  */
 @SpringBootApplication
 public class Application {
 
     public static void main(String[] args) {
-        SpringApplication.run( Application.class, args);
+        SpringApplication.run(Application.class, args);
     }
 
 }

spring-boot-modules/spring-boot-libraries-3/src/main/java/com/baeldung/spring/modulith/cqrs/movie/AvailableMovieSeats.java

@@ -0,0 +1,11 @@
+package com.baeldung.spring.modulith.cqrs.movie;
+
+import java.time.Instant;
+import java.util.List;
+
+import org.jmolecules.architecture.cqrs.QueryModel;
+
+@QueryModel
+record AvailableMovieSeats(String title, String screenRoom, Instant startTime, List<String> freeSeats) {
+
+}

spring-boot-modules/spring-boot-libraries-3/src/main/java/com/baeldung/spring/modulith/cqrs/movie/Movie.java

@@ -0,0 +1,97 @@
+package com.baeldung.spring.modulith.cqrs.movie;
+
+import java.time.Instant;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.stream.IntStream;
+
+import jakarta.persistence.CollectionTable;
+import jakarta.persistence.Column;
+import jakarta.persistence.ElementCollection;
+import jakarta.persistence.Entity;
+import jakarta.persistence.GeneratedValue;
+import jakarta.persistence.Id;
+import jakarta.persistence.JoinColumn;
+
+@Entity
+class Movie {
+
+    @Id
+    @GeneratedValue
+    private Long id;
+    private String title;
+    private String screenRoom;
+    private Instant startTime;
+
+    @ElementCollection
+    @CollectionTable(name = "screen_room_free_seats", joinColumns = @JoinColumn(name = "room_id"))
+    @Column(name = "seat_number")
+    private List<String> freeSeats = allSeats();
+
+    @ElementCollection
+    @CollectionTable(name = "screen_room_occupied_seats", joinColumns = @JoinColumn(name = "room_id"))
+    @Column(name = "seat_number")
+    private List<String> occupiedSeats = new ArrayList<>();
+
+    Movie(String movieName, String screenRoom, Instant startTime) {
+        this.title = movieName;
+        this.screenRoom = screenRoom;
+        this.startTime = startTime;
+    }
+
+    void occupySeat(String seatNumber) {
+        if (freeSeats.contains(seatNumber)) {
+            freeSeats.remove(seatNumber);
+            occupiedSeats.add(seatNumber);
+        } else {
+            throw new IllegalArgumentException("Seat " + seatNumber + " is not available.");
+        }
+    }
+
+    void freeSeat(String seatNumber) {
+        if (occupiedSeats.contains(seatNumber)) {
+            occupiedSeats.remove(seatNumber);
+            freeSeats.add(seatNumber);
+        } else {
+            throw new IllegalArgumentException("Seat " + seatNumber + " is not currently occupied.");
+        }
+    }
+
+    static List<String> allSeats() {
+        List<Integer> rows = IntStream.range(1, 20)
+            .boxed()
+            .toList();
+
+        return IntStream.rangeClosed('A', 'J')
+            .mapToObj(c -> String.valueOf((char) c))
+            .flatMap(col -> rows.stream()
+                .map(row -> col + row))
+            .sorted()
+            .toList();
+    }
+
+    protected Movie() {
+        // Default constructor for JPA
+    }
+
+    Instant startTime() {
+        return startTime;
+    }
+
+    String title() {
+        return title;
+    }
+
+    String screenRoom() {
+        return screenRoom;
+    }
+
+    List<String> freeSeats() {
+        return List.copyOf(freeSeats);
+    }
+
+    List<String> occupiedSeatsSeats() {
+        return List.copyOf(freeSeats);
+    }
+}
+

spring-boot-modules/spring-boot-libraries-3/src/main/java/com/baeldung/spring/modulith/cqrs/movie/MovieController.java

@@ -0,0 +1,51 @@
+package com.baeldung.spring.modulith.cqrs.movie;
+
+import static java.time.Instant.now;
+import static java.time.temporal.ChronoUnit.DAYS;
+
+import java.time.Instant;
+import java.util.List;
+
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.PathVariable;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RequestParam;
+import org.springframework.web.bind.annotation.RestController;
+
+@RestController
+@RequestMapping("/api/movies")
+class MovieController {
+
+    private final MovieRepository movieScreens;
+
+    MovieController(MovieRepository screenRooms) {
+        this.movieScreens = screenRooms;
+    }
+
+    /*
+        curl -X GET "http://localhost:8080/api/seating/movies?range=week"
+    */
+    @GetMapping
+    List<UpcomingMovies> moviesToday(@RequestParam String range) {
+        Instant endTime = endTime(range);
+        return movieScreens.findUpcomingMoviesByStartTimeBetween(now(), endTime.truncatedTo(DAYS));
+    }
+
+    /*
+        curl -X GET http://localhost:8080/api/movies/1/seats
+    */
+    @GetMapping("/{movieId}/seats")
+    ResponseEntity<AvailableMovieSeats> movieSeating(@PathVariable Long movieId) {
+        return ResponseEntity.of(movieScreens.findAvailableSeatsByMovieId(movieId));
+    }
+
+    private static Instant endTime(String range) {
+        return switch (range) {
+            case "day" -> now().plus(1, DAYS);
+            case "week" -> now().plus(7, DAYS);
+            case "month" -> now().plus(30, DAYS);
+            default -> throw new IllegalArgumentException("Invalid range: " + range);
+        };
+    }
+}

spring-boot-modules/spring-boot-libraries-3/src/main/java/com/baeldung/spring/modulith/cqrs/movie/MovieRepository.java

@@ -0,0 +1,16 @@
+package com.baeldung.spring.modulith.cqrs.movie;
+
+import java.time.Instant;
+import java.util.List;
+import java.util.Optional;
+
+import org.springframework.data.jpa.repository.JpaRepository;
+
+interface MovieRepository extends JpaRepository<Movie, Long> {
+
+    List<UpcomingMovies> findUpcomingMoviesByStartTimeBetween(Instant start, Instant end);
+
+    default Optional<AvailableMovieSeats> findAvailableSeatsByMovieId(Long movieId) {
+        return findById(movieId).map(movie -> new AvailableMovieSeats(movie.title(), movie.screenRoom(), movie.startTime(), movie.freeSeats()));
+    }
+}

spring-boot-modules/spring-boot-libraries-3/src/main/java/com/baeldung/spring/modulith/cqrs/movie/TicketBookingEventHandler.java

@@ -0,0 +1,56 @@
+package com.baeldung.spring.modulith.cqrs.movie;
+
+import static java.time.temporal.ChronoUnit.HOURS;
+
+import java.time.Instant;
+import java.util.List;
+import java.util.stream.LongStream;
+
+import org.jmolecules.event.annotation.DomainEventHandler;
+import org.springframework.boot.context.event.ApplicationReadyEvent;
+import org.springframework.context.event.EventListener;
+import org.springframework.modulith.events.ApplicationModuleListener;
+import org.springframework.stereotype.Component;
+
+import com.baeldung.spring.modulith.cqrs.ticket.BookingCancelled;
+import com.baeldung.spring.modulith.cqrs.ticket.BookingCreated;
+
+@Component
+class TicketBookingEventHandler {
+
+    private final MovieRepository screenRooms;
+
+    TicketBookingEventHandler(MovieRepository screenRooms) {
+        this.screenRooms = screenRooms;
+    }
+
+    @DomainEventHandler
+    @ApplicationModuleListener
+    void handleTicketBooked(BookingCreated booking) {
+        Movie room = screenRooms.findById(booking.movieId())
+            .orElseThrow();
+
+        room.occupySeat(booking.seatNumber());
+        screenRooms.save(room);
+    }
+
+    @DomainEventHandler
+    @ApplicationModuleListener
+    void handleTicketCancelled(BookingCancelled cancellation) {
+        Movie room = screenRooms.findById(cancellation.movieId())
+            .orElseThrow();
+
+        room.freeSeat(cancellation.seatNumber());
+        screenRooms.save(room);
+    }
+
+    @EventListener(ApplicationReadyEvent.class)
+    void insertDummyMovies() {
+        List<Movie> dummyMovies = LongStream.range(1, 30)
+            .mapToObj(nr -> new Movie("Dummy movie #" + nr, "Screen #" + nr % 5, Instant.now()
+                .plus(nr, HOURS)))
+            .toList();
+        screenRooms.saveAll(dummyMovies);
+    }
+
+}

spring-boot-modules/spring-boot-libraries-3/src/main/java/com/baeldung/spring/modulith/cqrs/movie/UpcomingMovies.java

@@ -0,0 +1,9 @@
+package com.baeldung.spring.modulith.cqrs.movie;
+
+import java.time.Instant;
+
+import org.jmolecules.architecture.cqrs.QueryModel;
+
+@QueryModel
+record UpcomingMovies(Long id, String title, Instant startTime) {
+}

spring-boot-modules/spring-boot-libraries-3/src/main/java/com/baeldung/spring/modulith/cqrs/ticket/BookTicket.java

@@ -0,0 +1,8 @@
+package com.baeldung.spring.modulith.cqrs.ticket;
+
+import org.jmolecules.architecture.cqrs.Command;
+
+@Command
+record BookTicket(Long movieId, String seat) {
+
+}

spring-boot-modules/spring-boot-libraries-3/src/main/java/com/baeldung/spring/modulith/cqrs/ticket/BookedTicket.java

@@ -0,0 +1,67 @@
+package com.baeldung.spring.modulith.cqrs.ticket;
+
+import java.time.Instant;
+
+import jakarta.persistence.Entity;
+import jakarta.persistence.GeneratedValue;
+import jakarta.persistence.Id;
+
+@Entity
+class BookedTicket {
+
+    @Id
+    @GeneratedValue
+    private Long id;
+    private Long movieId;
+    private String seatNumber;
+    private Instant createdAt = Instant.now();
+    private Status status = Status.BOOKED;
+
+    BookedTicket cancelledBooking() {
+        BookedTicket cancelled = new BookedTicket(movieId, seatNumber);
+        cancelled.status = Status.BOOKING_CANCELLED;
+        return cancelled;
+    }
+
+    enum Status {
+        BOOKED,
+        BOOKING_CANCELLED
+    }
+
+    boolean isBooked() {
+        return status == Status.BOOKED;
+    }
+
+    boolean isCancelled() {
+        return status == Status.BOOKING_CANCELLED;
+    }
+
+    BookedTicket(Long movieId, String seatNumber) {
+        this.movieId = movieId;
+        this.seatNumber = seatNumber;
+    }
+
+    Long id() {
+        return id;
+    }
+
+    Long movieId() {
+        return movieId;
+    }
+
+    String seatNumber() {
+        return seatNumber;
+    }
+
+    Instant createdAt() {
+        return createdAt;
+    }
+
+    Status status() {
+        return status;
+    }
+
+    protected BookedTicket() {
+        // Default constructor for JPA
+    }
+}