Welcome to another installment of This Week in Spring! This week I'm in Munich and Wolfsburg, Germany, visiting with customers, then it's off to Seoul, South Korea, for customers and some user group talks.

This week we've got a lot of exciting Spring Cloud Data Flow news, coincident with the new Spring Cloud Data Flow RC1

• The good Dr. Pollack, co-lead of the Spring Cloud Data Flow project, just announced Spring Cloud Data Flow RC1 which has updated deployers supporting deployments locally and to Apache YARN, Kubernetes, Mesos, and of course Cloud Foundry, an incredible integration of Spring Cloud Flo (a visualization for Spring Cloud Data Flow streams) into the Spring Cloud Data Flow Dashboard, improved OAuth support and so much more!
• I really enjoyed Mark Paluch's excellent blog pulling back the veil of obscurity around the security secrets sensation sweeping the nation, Hashicorp Vault, and how Spring Cloud Vault works…

Passwords, API keys and confidential data fall into the category of secrets. Storing secrets the secure way is a challenge with limiting access and a true secure storage. Let's take a look at Hashicorp Vault and how you can use it to store and access secrets.

How do you store Secrets?

Passwords, API keys, secure Tokens, and confidential data fall into the category of secrets. That's data which shouldn't lie around. It mustn't be available in plaintext in easy to guess locations. In fact, it must not be stored in plaintext in any location.

Sensitive data can be encrypted by using the Spring Cloud Config Server or TomEE. Encrypted data is one step better than unencrypted. Encryption imposes on the other side the need for decryption on the user side which requires a decryption key to be distributed. Now, where do you put the key? Is the key protected by a passphrase? Where do you put the passphrase? On how many systems do you distribute…

Welcome to another installment of This Week in Spring! This week I'm in Amsterdam, Holland to speak at the local Spring User Groups and with local companies, and then it's off to Krakow, Poland, Los Angeles, USA, Berlin, Germany and finally Seoul, South Korea! If you're in any of those regions, hit me up. Anyway, there's a lot of good stuff to get into this week so let's get to it!

• Spring Batch and Spring Cloud Task lead Michael Minella just announced Spring Cloud Task 1.0.0.RC1
• Spring Data ninja Mark Paluch just announced Spring Data Hopper SR2
• Spring Cloud cofounder Spencer Gibb just announced Spring Cloud Brixton.SR1
• the CodeCentric blog is back at it again, this time with a post on validation and custom SOAP faults
• I answered this question about Spring Boot's use of Maven starter dependencies
• I dig this blog introducing a custom, albeit alternative, way to do JWT (JSON Web Tokens) with Spring Cloud-based microservices…

Welcome to another installment of This Week in Spring! This week I'm in London and Amsterdam (for the epic GOTO Amsterdam conference as well as the JDriven meetup and the Dutch Spring User Group). We've got a lot to cover, as usual, so let's get to it!

• Spring framework 4.3, packed with all sorts of niceties, is now available. This release provides all sorts of cool updates to various libraries (Hibernate ORM, Jackson, Netty, Undertow, Tomcat) and supports two features I'm quite excited about: auto-injection in constructors of Spring managed components whose parameters are unambiguously resolved by other types in the application context and the ability to inject types into a @Configuration-class's constructor.
• Marius Bogoevici just announced a critical update to Spring Cloud Stream, 1.0.2.RELEASE, is now available for immediate use
• the good Dr. David Syer posted the second in a series of posts looking at the reactive programming landscape…

In this article we continue the series on Reactive Programming, and we concentrate on explaining some concepts through actual code samples. The end result should be that you understand a bit better what makes Reactive different, and what makes it functional. The examples here are quite abstract, but they give you a way to think about the APIs and the programming style, and start to get a feel for how it is different. We will see the elements of Reactive, and learn how to control the flow of data, and process in background threads if necessary.

Setting Up a Project

We will use the Reactor libraries to illustrate the points we need to make. The code could just as easily be written with other tools. If you want to play with the code and see it working without having to copy-paste anything, there are working samples with tests in Github…

Reactive Programming is interesting (again) and there is a lot of noise about it at the moment, not all of which is very easy to understand for an outsider and simple enterprise Java developer, such as the author. This article (the first in a series) might help to clarify your understanding of what the fuss is about. The approach is as concrete as possible, and there is no mention of "denotational semantics". If you are looking for a more academic approach and loads of code samples in Haskell, the internet is full of them, but you probably don’t want to be here.

Reactive Programming is often…

Welcome to another installment of This Week in Spring! It's already June! Where. Does. The. Time. GO?? This week I'm in Chicago, IL, for the Chicago Coder Conference, Boston and New Hampshire for customer visits, London, England for Devoxx UK and Talin, Estonia for Geekout EE. If you're around be sure to say hi! Now then, we've got a lot to cover this week so let's get to it!

• Spring Cloud Services ninja Scott Frederick just announced the Spring Cloud Cloud Foundry Service Broker, which is a nice framework for building service brokers for the Cloud Foundry platform
• Spring Boot and Spring Cloud co-founder (the good) Dr. Dave Syer just put published the first post in a series on the reactive programming landscape
• Spring Integration ninja Artem Bilan just announced that Spring Integration Kafka 2.0.0.RC1 is now available
• not one to rest on his laurels, Artem also announced the Spring for Apache Kafka 1.0. RC1
• Spring Cloud Streams lead Marius Bogoevici has just announced Spring Cloud Stream 1.0.1.RELEASE…

Greetings Spring community,

There has been a lot of buzz in the past six months over Spring 5 and Reactive Streams support. I personally witnessed the number of questions Rossen received during his Reactive Spring MVC talk at DevNexus back in March. And his reactive talk at Spring I/O conference more recently was VERY popular to attenders.

Based on the huge leaps and bounds Project Reactor has made in the past two years, we are taking two of our guides down:

• Creating an Asynchronous, Event-Driven Application with Reactor

• Uploading pictures with Reactor

Those guides are over two years old…

This article will explain in depth how to tackle issues related to database compatibility and the deployment process. We will present what can happen with your production applications if you try to perform such a deployment unprepared. We will then walk through the steps in the lifecycle of an application that are necessary to have zero downtime. The result of our operations will be applying a backward incompatible database change in a backward compatible way.

If you want to work through the code samples below, you will find everything you need in GitHub.

Introduction

Zero downtime deployment

What is this mythical zero downtime deployment? You can say that your application is deployed that way if you can successfully introduce a new version of your application to production without making the user see that the application went down in the meantime. From the user’s and the company’s point of view it’s the best possible scenario of deployment since new features can be introduced…