This Week in Spring - February 13th, 2018

Hi Spring fans! Welcome to another installment of This Week in Spring! This week I’ve been in Munich and Frankfurt, Germany, and Minneapolis, Minnesota, and it looks like i’ll be in New York City and San Francisco for the balance of the week.

We’ve got a lot to cover so without further ado so let’s get started.


Spring Cloud Contract in a polyglot world

This article contains a short reminder of what Contract Testing is, how Spring Cloud Contract implements it, and how Spring Cloud Contract can be used in a polyglot world.

What is Contract Testing

In order to increase the certainty that our systems behave properly, we write different types of tests. According to the test pyramid the main types of tests are unit, integration, and UI. The more complex the tests, the more time and effort they require and the more brittle they become.

In a distributed system, one of the most frequent problems is testing integrations between applications. Let’s assume that your service sends a REST request to another application. When using Spring Boot, you can write a @SpringBootTest in which you test that behavior. You set up a Spring context, you prepare a request to be sent…​ and where do you send it? You haven’t started the other application, so you get a Connection Refused exception. You can try mocking the real HTTP call and returning a fake response. However, if you do that, you do not test any real HTTP integration, serialization and deserialization mechanisms, and so on. You could also start a fake HTTP server (for example, WireMock) and simulate how it should behave. The problem here is that you, as a client of an API, define how the server behaves. In other words, if you tell the fake server to return text testText when a request is sent to endpoint /myEndpoint, it does just that, even if the real server does not have such an endpoint. In short, the problem is that the stubs might not be reliable.


Spring Integration for AWS 2.0.0.M1 and Spring Cloud Stream Kinesis Binder 1.0.0.M1

Dear Spring Community!

It’s my pleasure to announce two Spring Milestone releases for Amazon Web Services: Spring Integration for AWS 2.0.0.M1 and Spring Cloud Stream Binder for AWS Kinesis 1.0.0.M1.

Both milestones are available in the Spring Milestone repository and they can be consumed as maven dependencies:



Spring Cloud Finchley M6 is available

On behalf of the community, I am pleased to announce that the Milestone 6 (M6) of the Spring Cloud Finchley Release Train is available today. The release can be found in the Spring Milestone repository. You can check out the Finchley release notes for more information.

Notable Changes in the Finchley Release Train

Finchley.M6 is compatible with Spring Boot RC1. Many updates have been made for compatibility with RC1.

Spring Cloud Sleuth

The internals of Spring Cloud Sleuth were rewritten to use Brave. Please see the Migration Guide for more information.