Book Image

Mastering Spring Cloud

By : Piotr Mińkowski
Book Image

Mastering Spring Cloud

By: Piotr Mińkowski

Overview of this book

Developing, deploying, and operating cloud applications should be as easy as local applications. This should be the governing principle behind any cloud platform, library, or tool. Spring Cloud–an open-source library–makes it easy to develop JVM applications for the cloud. In this book, you will be introduced to Spring Cloud and will master its features from the application developer's point of view. This book begins by introducing you to microservices for Spring and the available feature set in Spring Cloud. You will learn to configure the Spring Cloud server and run the Eureka server to enable service registration and discovery. Then you will learn about techniques related to load balancing and circuit breaking and utilize all features of the Feign client. The book now delves into advanced topics where you will learn to implement distributed tracing solutions for Spring Cloud and build message-driven microservice architectures. Before running an application on Docker container s, you will master testing and securing techniques with Spring Cloud.
Table of Contents (22 chapters)
Title Page
Copyright and Credits
Packt Upsell

The advanced programming model

The basics around the Spring Cloud Stream programming model have been presented together with samples of point-to-point and publish/subscribe communication. Let's discuss some more advanced example features.

Producing messages

In all the samples presented in this chapter, we have sent orders through RESTful API for testing purposes. However, we may easily create some test data by defining the message source inside the application. Here's a bean that generates one message per second using @Poller and sends it to the output channel:

@InboundChannelAdapter(value = Source.OUTPUT, poller = @Poller(fixedDelay = "1000", maxMessagesPerPoll = "1"))
public MessageSource<Order> ordersSource() {
    Random r = new Random();
    return () -> new GenericMessage<>(new Order(OrderStatus.NEW, (long) r.nextInt(5), Collections.singletonList((long) r.nextInt(10))));


As you probably remember, account-service and product-service have been receiving...