9_Application Events and Listeners

build.gradle.kts

@@ -19,6 +19,10 @@ repositories {
 
 dependencies {
 	implementation("org.springframework.boot:spring-boot-starter")
+	implementation("org.springframework.boot:spring-boot-starter-web")
+	implementation("org.springframework.boot:spring-boot-starter-data-jpa")
+	compileOnly("org.projectlombok:lombok")
+	annotationProcessor("org.projectlombok:lombok")
 	testImplementation("org.springframework.boot:spring-boot-starter-test")
 	testRuntimeOnly("org.junit.platform:junit-platform-launcher")
 }

src/main/java/org/javaspringcourse/config/AsyncConfig.java

@@ -0,0 +1,16 @@
+package org.javaspringcourse.config;
+
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.scheduling.annotation.EnableAsync;
+import org.springframework.scheduling.concurrent.ThreadPoolTaskExecutor;
+
+@Configuration
+@EnableAsync
+public class AsyncConfig {
+
+    @Bean
+    ThreadPoolTaskExecutor threadPoolTaskExecutor() {
+        return new ThreadPoolTaskExecutor(); // TODO здесь можно определить ограничения для потоков асинхронных ивентов
+    };
+}

src/main/java/org/javaspringcourse/order/controller/OrderController.java

@@ -0,0 +1,21 @@
+package org.javaspringcourse.order.controller;
+
+import lombok.RequiredArgsConstructor;
+import org.javaspringcourse.order.dto.OrderIn;
+import org.javaspringcourse.order.service.OrderService;
+import org.springframework.web.bind.annotation.PostMapping;
+import org.springframework.web.bind.annotation.RequestBody;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RestController;
+
+@RestController
+@RequestMapping("/orders")
+@RequiredArgsConstructor
+public class OrderController {
+    private final OrderService orderService;
+
+    @PostMapping("/create")
+    public void getOrders(@RequestBody OrderIn order) {
+        orderService.createOrder(order.cost(), order.balance());
+    }
+}

src/main/java/org/javaspringcourse/order/dto/OrderIn.java

@@ -0,0 +1,3 @@
+package org.javaspringcourse.order.dto;
+
+public record OrderIn(float cost, float balance) {}

src/main/java/org/javaspringcourse/order/eventListener/OrderEventListener.java

@@ -0,0 +1,17 @@
+package org.javaspringcourse.order.eventListener;
+
+import lombok.extern.log4j.Log4j2;
+import org.javaspringcourse.order.eventListener.event.OrderCreatedEvent;
+import org.springframework.context.event.EventListener;
+import org.springframework.stereotype.Component;
+
+@Log4j2
+@Component
+public class OrderEventListener {
+
+    @EventListener
+    public void handleOrderCreatedEvent(OrderCreatedEvent event) {
+        log.info("Handle OrderCreatedEvent...");
+        log.info("Order was created.");
+    }
+}

src/main/java/org/javaspringcourse/order/eventListener/PaymentProcessedEventListener.java

@@ -0,0 +1,31 @@
+package org.javaspringcourse.order.eventListener;
+
+import lombok.RequiredArgsConstructor;
+import lombok.extern.log4j.Log4j2;
+import org.javaspringcourse.order.eventListener.event.OrderCreatedEvent;
+import org.javaspringcourse.payment.eventListener.event.PaymentProcessedEvent;
+import org.springframework.context.ApplicationEventPublisher;
+import org.springframework.scheduling.annotation.Async;
+import org.springframework.stereotype.Component;
+import org.springframework.transaction.event.TransactionPhase;
+import org.springframework.transaction.event.TransactionalEventListener;
+
+@Log4j2
+@Component
+@RequiredArgsConstructor
+public class PaymentProcessedEventListener {
+    private final ApplicationEventPublisher eventPublisher;
+
+    @TransactionalEventListener(phase = TransactionPhase.AFTER_COMMIT)
+    public void handlePaymentSuccessEvent(PaymentProcessedEvent event) {
+        log.info("Handle PaymentProcessedEvent (AFTER_COMMIT)...");
+        log.info("Publish OrderCreatedEvent.");
+        eventPublisher.publishEvent(new OrderCreatedEvent());
+    }
+
+    @TransactionalEventListener(phase = TransactionPhase.AFTER_ROLLBACK)
+    public void handlePaymentFailEvent(PaymentProcessedEvent event) {
+        log.info("Handle PaymentProcessedEvent (AFTER_ROLLBACK)...");
+        log.info("Order has been cancelled.");
+    }
+}

src/main/java/org/javaspringcourse/order/eventListener/event/OrderCreatedEvent.java

@@ -0,0 +1,4 @@
+package org.javaspringcourse.order.eventListener.event;
+
+public record OrderCreatedEvent() {
+}

src/main/java/org/javaspringcourse/order/eventListener/event/OrderCreatingEvent.java

@@ -0,0 +1,4 @@
+package org.javaspringcourse.order.eventListener.event;
+
+public record OrderCreatingEvent(float cost, float money) {
+}

src/main/java/org/javaspringcourse/order/service/OrderService.java

@@ -0,0 +1,24 @@
+package org.javaspringcourse.order.service;
+
+import jakarta.transaction.Transactional;
+import lombok.RequiredArgsConstructor;
+import lombok.extern.log4j.Log4j2;
+import org.javaspringcourse.order.eventListener.event.OrderCreatingEvent;
+import org.springframework.context.ApplicationEventPublisher;
+import org.springframework.stereotype.Service;
+import org.springframework.transaction.support.TransactionSynchronizationManager;
+
+@Log4j2
+@Service
+@RequiredArgsConstructor
+public class OrderService {
+    private final ApplicationEventPublisher eventPublisher;
+
+    public void createOrder(float cost, float money) {
+        log.info("Creating an order...");
+        log.info("Waiting for payment...");
+
+        log.info("Publish OrderCreatingEvent.");
+        eventPublisher.publishEvent(new OrderCreatingEvent(cost, money));
+    }
+}

src/main/java/org/javaspringcourse/payment/eventListener/OrderCreatingEventListener.java

@@ -0,0 +1,27 @@
+package org.javaspringcourse.payment.eventListener;
+
+import lombok.RequiredArgsConstructor;
+import lombok.extern.log4j.Log4j2;
+import org.javaspringcourse.order.eventListener.event.OrderCreatingEvent;
+import org.javaspringcourse.payment.service.PaymentService;
+import org.springframework.context.event.EventListener;
+import org.springframework.scheduling.annotation.Async;
+import org.springframework.stereotype.Component;
+
+@Log4j2
+@Component
+@RequiredArgsConstructor
+public class OrderCreatingEventListener {
+    private final PaymentService paymentService;
+
+    @EventListener
+    @Async("threadPoolTaskExecutor")
+    public void handleOrderCreatingEvent(OrderCreatingEvent event) throws InterruptedException {
+        Thread.sleep(2000); // имитация долгой работы
+        try {
+            paymentService.processPayment(event.money(), event.cost());
+        } catch (Exception e) {
+            log.warn(e);
+        }
+    }
+}

src/main/java/org/javaspringcourse/payment/eventListener/PaymentEventListener.java

@@ -0,0 +1,27 @@
+package org.javaspringcourse.payment.eventListener;
+
+import lombok.RequiredArgsConstructor;
+import lombok.extern.log4j.Log4j2;
+import org.javaspringcourse.payment.eventListener.event.PaymentProcessedEvent;
+import org.springframework.scheduling.annotation.Async;
+import org.springframework.stereotype.Component;
+import org.springframework.transaction.event.TransactionPhase;
+import org.springframework.transaction.event.TransactionalEventListener;
+
+@Log4j2
+@Component
+@RequiredArgsConstructor
+public class PaymentEventListener {
+
+    @TransactionalEventListener(phase = TransactionPhase.AFTER_COMMIT)
+    public void handlePaymentSuccessEvent(PaymentProcessedEvent event) {
+        log.info("Handle PaymentProcessedEvent (AFTER_COMMIT)...");
+        log.info("Payment was successful.");
+    }
+
+    @TransactionalEventListener(phase = TransactionPhase.AFTER_ROLLBACK)
+    public void handlePaymentFailEvent(PaymentProcessedEvent event) {
+        log.info("Handle PaymentProcessedEvent (AFTER_ROLLBACK)...");
+        log.info("Payment failed.");
+    }
+}

src/main/java/org/javaspringcourse/payment/eventListener/event/PaymentProcessedEvent.java

@@ -0,0 +1,4 @@
+package org.javaspringcourse.payment.eventListener.event;
+
+public record PaymentProcessedEvent() {
+}

src/main/java/org/javaspringcourse/payment/service/PaymentService.java

@@ -0,0 +1,34 @@
+package org.javaspringcourse.payment.service;
+
+import jakarta.transaction.Transactional;
+import lombok.RequiredArgsConstructor;
+import lombok.extern.log4j.Log4j2;
+import org.javaspringcourse.payment.eventListener.event.PaymentProcessedEvent;
+import org.springframework.context.ApplicationEventPublisher;
+import org.springframework.stereotype.Service;
+import org.springframework.transaction.support.TransactionSynchronizationManager;
+
+import static jakarta.transaction.Transactional.TxType.REQUIRES_NEW;
+
+@Log4j2
+@Service
+@RequiredArgsConstructor
+public class PaymentService {
+    private final ApplicationEventPublisher eventPublisher;
+
+    @Transactional(value = REQUIRES_NEW, rollbackOn = Exception.class)
+    public void processPayment(float money, float need) {
+        log.info("Trying to pay for order. Current money: {}", money);
+        log.info("Publish PaymentProcessedEvent.");
+        eventPublisher.publishEvent(new PaymentProcessedEvent());
+
+        log.info("In transaction: {}", TransactionSynchronizationManager.isActualTransactionActive());
+
+        if (money > need) {
+            log.info("Payment Working...");
+            log.info("Fixing in DB...");
+        } else {
+            throw new RuntimeException("NO MONEY TO PAY");
+        }
+    }
+}

src/main/resources/application.properties

@@ -1 +1,3 @@
 spring.application.name=java-spring-course
+spring.autoconfigure.exclude=org.springframework.boot.autoconfigure.jdbc.DataSourceAutoConfiguration
+server.port=8080