Merge pull request #45 from eamtalu/develop

#33 OpenAccountUseCase - Publishing events

README.md

@@ -25,14 +25,6 @@ We implement a Banking system with the following use cases:
 
 ## Environment variables
 
-When you open up the file `application.yml` we can see the usage of the following environment variables for the Postgres Database
-
-```
-url: ${POSTGRES_URL}
-username: ${POSTGRES_USER}
-password: ${POSTGRES_PASSWORD}
-```
-
 To be able to run the tests (since some of the tests are dependent on the database - the integration tests), we then need to set the environment variables.
 
 In IntelliJ, for the `Tests in 'banking-kata.test'` configuration, you can copy this into the `Environment variables`

docker-compose.yml

@@ -1,13 +1,15 @@
+version: '3.8'
 services:
-  postgres:
-    image: postgres:latest
-    container_name: postgres
+  db:
+    image: postgres:14.1-alpine
+    restart: always
+    environment:
+      - POSTGRES_USER=postgres
+      - POSTGRES_PASSWORD=postgres
     ports:
-      - "5432:5432"
-    restart: unless-stopped
+      - '5432:5432'
     volumes:
-      - ./db_persist:/var/lib/postgresql/data
-    environment:
-      POSTGRES_USER: ${POSTGRES_USER}
-      POSTGRES_PASSWORD: ${POSTGRES_PASSWORD}
-      POSTGRES_DB: ${POSTGRES_DB}
+      - db:/var/lib/postgresql/data
+volumes:
+  db:
+    driver: local

src/main/java/com/optivem/kata/banking/core/domain/common/events/EventPublisher.java

@@ -0,0 +1,8 @@
+package com.optivem.kata.banking.core.domain.common.events;
+
+/**
+ * Event Publisher interface will provide eventpublishing functionality to usecases
+ */
+public interface EventPublisher {
+    public void publishEvent(UseCaseEvent event);
+}

src/main/java/com/optivem/kata/banking/core/domain/common/events/EventPublisherToQueue.java

@@ -0,0 +1,21 @@
+package com.optivem.kata.banking.core.domain.common.events;
+
+
+import org.springframework.context.ApplicationEventPublisher;
+import org.springframework.stereotype.Component;
+
+
+@Component
+public class EventPublisherToQueue implements EventPublisher {
+
+    private ApplicationEventPublisher applicationEventPublisher;
+
+    public EventPublisherToQueue(ApplicationEventPublisher applicationEventPublisher){
+        this.applicationEventPublisher = applicationEventPublisher;
+    }
+
+    @Override
+    public void publishEvent(UseCaseEvent event) {
+        applicationEventPublisher.publishEvent(event);
+    }
+}

src/main/java/com/optivem/kata/banking/core/domain/common/events/UseCaseEvent.java

@@ -0,0 +1,24 @@
+package com.optivem.kata.banking.core.domain.common.events;
+
+import com.optivem.kata.banking.core.domain.accounts.AccountId;
+import lombok.Getter;
+import org.springframework.context.ApplicationEvent;
+
+import java.time.LocalDateTime;
+
+/**
+ * This class serves as the Event Object that to be puslished by ApplicationEventPublisher
+ */
+@Getter
+public class UseCaseEvent extends ApplicationEvent {
+
+    private AccountId id;
+    private String eventName;
+    private LocalDateTime localDateTime;
+    public UseCaseEvent(AccountId id, String eventName) {
+        super(id);
+        this.id = id;
+        this.eventName = eventName;
+        this.localDateTime = LocalDateTime.now();
+    }
+}

src/main/java/com/optivem/kata/banking/core/domain/common/events/UseCaseEventHandler.java

@@ -0,0 +1,31 @@
+package com.optivem.kata.banking.core.domain.common.events;
+
+import com.optivem.kata.banking.infra.real.inmemory.EventQueue;
+import org.springframework.context.event.EventListener;
+import org.springframework.stereotype.Component;
+
+/**
+ * EventListener class that will observe any event of type UseCaseEvent and act accordingly
+ * It will also insert the event into queue.
+ */
+@Component
+public class UseCaseEventHandler{
+
+    private final EventQueue<UseCaseEvent> queue;
+
+    public UseCaseEventHandler(EventQueue<UseCaseEvent> eventEventQueue){
+        this.queue = eventEventQueue;
+    }
+
+    @EventListener
+    public void handleEvent(UseCaseEvent event){
+            queue.addEvent(event);
+
+            // var eventFromQueue = queue.next();
+            // System.out.println(eventFromQueue.getId());
+            // System.out.println(eventFromQueue.getEventName());
+            // System.out.println(eventFromQueue.getLocalDateTime());
+
+    }
+
+}

src/main/java/com/optivem/kata/banking/core/domain/common/events/UseCaseEvents/AccountOpenedUseCaseEvent.java

@@ -0,0 +1,14 @@
+package com.optivem.kata.banking.core.domain.common.events.UseCaseEvents;
+
+
+import com.optivem.kata.banking.core.domain.accounts.AccountId;
+import com.optivem.kata.banking.core.domain.common.events.UseCaseEvent;
+
+public class AccountOpenedUseCaseEvent {
+
+    public static UseCaseEvent generateEventOnSuccess(AccountId id){
+        return new UseCaseEvent(id,"AccountOpened");
+    }
+
+
+}

src/main/java/com/optivem/kata/banking/infra/real/inmemory/EventQueue.java

@@ -0,0 +1,30 @@
+package com.optivem.kata.banking.infra.real.inmemory;
+
+import org.springframework.stereotype.Component;
+
+import java.util.ArrayDeque;
+import java.util.NoSuchElementException;
+import java.util.Queue;
+
+
+@Component
+public class EventQueue<T> {
+
+    private final Queue<T> queue;
+
+    public EventQueue(){
+        this.queue = new ArrayDeque<>();
+    }
+
+    public void addEvent(T event){
+           queue.add(event);
+    }
+
+    public T next(){
+        if(queue.isEmpty()){
+            throw new NoSuchElementException();
+        }
+        return queue.remove();
+    }
+
+}