BAEL-7143: virtual threads vs webflux

2023-11-30 18:11:39 +01:00
parent eff24a8f7e
commit 208ff083c8
23 changed files with 351 additions and 5 deletions
@@ -0,0 +1,13 @@
+package com.baeldung.spring.reactive.performance;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+@SpringBootApplication
+public class Application {
+
+    public static void main(String[] args) {
+        SpringApplication.run(Application.class, args);
+    }
+    
+}
@@ -0,0 +1,14 @@
+package com.baeldung.spring.reactive.performance;
+
+import java.util.concurrent.CompletableFuture;
+
+public class KafkaTemplate<K, V> {
+
+    // For simplicity in this example and article, an actual Kafka client isn't utilized.
+    // The focus remains on demonstrating the basic principles without the complexities of a full Kafka client setup.
+
+    public CompletableFuture<Void> send(String topic, K key, V value) {
+        System.out.println("Sending message to topic: " + topic + " with value: " + value);
+        return CompletableFuture.completedFuture(null);
+    }
+}
@@ -0,0 +1,6 @@
+package com.baeldung.spring.reactive.performance;
+
+import java.math.BigDecimal;
+
+public record ProductAddedToCartEvent(String productId, BigDecimal price, String currency, String cartId) {
+}
@@ -0,0 +1,9 @@
+package com.baeldung.spring.reactive.performance.model;
+
+import java.math.BigDecimal;
+
+public record Price(BigDecimal value, String currency) {
+    public Price applyDiscount(BigDecimal discount) {
+        return new Price(value.subtract(discount), currency);
+    }
+}
@@ -0,0 +1,43 @@
+package com.baeldung.spring.reactive.performance.model;
+
+import java.math.BigDecimal;
+
+import org.springframework.data.annotation.Id;
+import org.springframework.data.mongodb.core.mapping.Document;
+
+@Document(collation = "products")
+public record Product (
+    @Id
+    String id,
+    String name,
+    BigDecimal basePriceValue,
+    String currency,
+    Category category
+) {
+
+    public Price basePrice() {
+        return new Price(basePriceValue, currency);
+    }
+
+    public enum Category {
+        ELECTRONICS(false),
+        CLOTHING(true),
+        ACCESSORIES(false),
+        GARDENING(false),
+        SPORTS(true);
+
+        private final boolean eligibleForPromotion;
+
+        Category(boolean eligibleForPromotion) {
+            this.eligibleForPromotion = eligibleForPromotion;
+        }
+
+        public boolean isEligibleForDiscount() {
+            return eligibleForPromotion;
+        }
+
+        public boolean notEligibleForPromotion() {
+            return !eligibleForPromotion;
+        }
+    }
+}
@@ -0,0 +1,11 @@
+package com.baeldung.spring.reactive.performance.virtualthreads;
+
+import java.math.BigDecimal;
+
+class DiscountService {
+
+    public BigDecimal discountForProduct(String productId) {
+        return BigDecimal.valueOf(10);
+    }
+
+}
@@ -0,0 +1,8 @@
+package com.baeldung.spring.reactive.performance.virtualthreads;
+
+import org.springframework.data.mongodb.repository.MongoRepository;
+
+import com.baeldung.spring.reactive.performance.model.Product;
+
+interface ProductRepository extends MongoRepository<Product, String> {
+}
@@ -0,0 +1,47 @@
+package com.baeldung.spring.reactive.performance.virtualthreads;
+
+import java.math.BigDecimal;
+
+import com.baeldung.spring.reactive.performance.KafkaTemplate;
+import com.baeldung.spring.reactive.performance.ProductAddedToCartEvent;
+import com.baeldung.spring.reactive.performance.model.Price;
+import com.baeldung.spring.reactive.performance.model.Product;
+
+class ProductService {
+    private final String PRODUCT_ADDED_TO_CART_TOPIC = "product-added-to-cart";
+
+    private final ProductRepository repository;
+    private final DiscountService discountService;
+    private final KafkaTemplate<String, ProductAddedToCartEvent> kafkaTemplate;
+
+    public ProductService(ProductRepository repository, DiscountService discountService) {
+        this.repository = repository;
+        this.discountService = discountService;
+        this.kafkaTemplate = new KafkaTemplate<>();
+    }
+
+    public void addProductToCart(String productId, String cartId) {
+        Thread.startVirtualThread(() -> computePriceAndPublishMessage(productId, cartId));
+    }
+
+    private void computePriceAndPublishMessage(String productId, String cartId) {
+        Product product = repository.findById(productId)
+            .orElseThrow(() -> new IllegalArgumentException("not found!"));
+
+        Price price = computePrice(productId, product);
+
+        var event = new ProductAddedToCartEvent(productId, price.value(), price.currency(), cartId);
+        kafkaTemplate.send(PRODUCT_ADDED_TO_CART_TOPIC, cartId, event);
+    }
+
+    private Price computePrice(String productId, Product product) {
+        if (product.category()
+            .isEligibleForDiscount()) {
+            BigDecimal discount = discountService.discountForProduct(productId);
+            return product.basePrice()
+                .applyDiscount(discount);
+        }
+        return product.basePrice();
+    }
+
+}
@@ -0,0 +1,11 @@
+package com.baeldung.spring.reactive.performance.webflux;
+
+import java.math.BigDecimal;
+
+import reactor.core.publisher.Mono;
+
+class DiscountService {
+    public Mono<BigDecimal> discountForProduct(String productId) {
+        return Mono.just(BigDecimal.valueOf(10));
+    }
+}
@@ -0,0 +1,8 @@
+package com.baeldung.spring.reactive.performance.webflux;
+
+import org.springframework.data.mongodb.repository.ReactiveMongoRepository;
+
+import com.baeldung.spring.reactive.performance.model.Product;
+
+interface ProductRepository extends ReactiveMongoRepository<Product, String> {
+}
@@ -0,0 +1,40 @@
+package com.baeldung.spring.reactive.performance.webflux;
+
+import com.baeldung.spring.reactive.performance.KafkaTemplate;
+import com.baeldung.spring.reactive.performance.ProductAddedToCartEvent;
+import com.baeldung.spring.reactive.performance.model.Price;
+import com.baeldung.spring.reactive.performance.model.Product;
+
+import reactor.core.publisher.Mono;
+
+class ProductService {
+    private final String PRODUCT_ADDED_TO_CART_TOPIC = "product-added-to-cart";
+
+    private final ProductRepository repository;
+    private final DiscountService discountService;
+    private final KafkaTemplate<String, ProductAddedToCartEvent> kafkaTemplate;
+
+    public ProductService(ProductRepository repository, DiscountService discountService) {
+        this.repository = repository;
+        this.discountService = discountService;
+        this.kafkaTemplate = new KafkaTemplate<>();
+    }
+
+    public void addProductToCart(String productId, String cartId) {
+        repository.findById(productId)
+            .switchIfEmpty(Mono.error(() -> new IllegalArgumentException("not found!")))
+            .flatMap(this::computePrice)
+            .map(price -> new ProductAddedToCartEvent(productId, price.value(), price.currency(), cartId))
+            .subscribe(event -> kafkaTemplate.send(PRODUCT_ADDED_TO_CART_TOPIC, cartId, event));
+    }
+
+    private Mono<Price> computePrice(Product product) {
+        if (product.category()
+            .isEligibleForDiscount()) {
+            return discountService.discountForProduct(product.id())
+                .map(product.basePrice()::applyDiscount);
+        }
+        return Mono.just(product.basePrice());
+    }
+
+}
@@ -0,0 +1,5 @@
+
+  
+      
+    
+    
@@ -0,0 +1,13 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<configuration>
+    <appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
+        <encoder>
+            <pattern>%d{HH:mm:ss.SSS} [%thread] %-5level %logger{36} - %msg%n
+            </pattern>
+        </encoder>
+    </appender>
+
+    <root level="INFO">
+        <appender-ref ref="STDOUT" />
+    </root>
+</configuration>
@@ -0,0 +1,12 @@
+package com.baeldung.spring.reactive.performance;
+
+import org.junit.Test;
+import org.springframework.boot.test.context.SpringBootTest;
+
+@SpringBootTest
+public class ApplicationUnitTest {
+
+    @Test
+    public void whenSpringContextIsBootstrapped_thenNoExceptions() {
+    }
+}