Java Weekly, Issue 244
Last updated: July 3, 2022
Mocking is an essential part of unit testing, and the Mockito library makes it easy to write clean and intuitive unit tests for your Java code.
Get started with mocking and improve your application tests using our Mockito guide:
Spring 5 added support for reactive programming with the Spring WebFlux module, which has been improved upon ever since. Get started with the Reactor project basics and reactive programming in Spring Boot:
Since its introduction in Java 8, the Stream API has become a staple of Java development. The basic operations like iterating, filtering, mapping sequences of elements are deceptively simple to use.
But these can also be overused and fall into some common pitfalls.
To get a better understanding on how Streams work and how to combine them with other language features, check out our guide to Java Streams:
Explore Spring Boot 3 and Spring 6 in-depth through building a full REST API with the framework:
Yes, Spring Security can be complex, from the more advanced functionality within the Core to the deep OAuth support in the framework.
I built the security material as two full courses - Core and OAuth, to get practical with these more complex scenarios. We explore when and how to use each feature and code through it on the backing project.
You can explore the course here:
Spring Data JPA is a great way to handle the complexity of JPA with the powerful simplicity of Spring Boot.
Get started with Spring Data JPA through the guided reference course:
Refactor Java code safely — and automatically — with OpenRewrite.
Refactoring big codebases by hand is slow, risky, and easy to put off. That’s where OpenRewrite comes in. The open-source framework for large-scale, automated code transformations helps teams modernize safely and consistently.
Each month, the creators and maintainers of OpenRewrite at Moderne run live, hands-on training sessions — one for newcomers and one for experienced users. You’ll see how recipes work, how to apply them across projects, and how to modernize code with confidence.
Join the next session, bring your questions, and learn how to automate the kind of work that usually eats your sprint time.
Yes, we're now running our Spring Sale. All Courses are 30% off until 31st March, 2026
In distributed systems, managing multi-step processes (e.g., validating a driver, calculating fares, notifying users) can be difficult. We need to manage state, scattered retry logic, and maintain context when services fail.
Dapr Workflows solves this via Durable Execution which includes automatic state persistence, replaying workflows after failures and built-in resilience through retries, timeouts and error handling.
In this tutorial, we'll see how to orchestrate a multi-step flow for a ride-hailing application by integrating Dapr Workflows and Spring Boot:
Yes, we're now running our Spring Sale. All Courses are 30% off until 31st March, 2026
Here we go…
1. Spring and Java
>> Optimistic locking in JPA/Hibernate [blog.arnoldgalovics.com]
A good review of lost update anomalies and how to detect them using versioned and non-versioned optimistic database locks.
>> Bootiful GCP: Relational Data Access with Spring Cloud GCP (2/8) [spring.io]
In this installment in the series on Spring Boot and the Google Cloud Platform, we see how easy it is to connect to a managed MySQL database and perform some basic queries.
>> Bootiful GCP: Globally Consistent Data Access with Spanner (3/8) [spring.io]
And for an encore, this tutorial walks us through integrating to Google Spanner using Spring Data. Very cool.
>> Hibernate Tips: Map 1 Entity Attribute to 2 Columns [thoughts-on-java.org]
A nice write-up gives us a way to solve a problem commonly seen in legacy database code by using a transient property and two internal attributes.
>> Hibernate database schema multitenancy [vladmihalcea.com]
In this follow-up to last week’s piece on catalog-based multitenancy, we see how schema-based multitenancy is suitable for databases that drive a clear distinction between a catalog and schema, such as PostgreSQL.
>> Build a MySQL Spring Boot App Running on WildFly on an Azure VM [infoq.com]
A good tutorial on creating a MySQL server using Azure Database for MySQL and connecting to it from a Wildfly-based Spring Boot app. Good stuff.
>> Java is still available at zero-cost [blog.joda.org]
Despite the rumors, Java is still free, but be prepared to shell out big bucks if you insist on remaining on older versions and still rely on Oracle for support.
>> Migrate Maven Projects to Java 11 [winterbe.com]
A solid resource if you simply want to run your applications on JDK 11 but don’t care about the new Jigsaw module system.
Also worth reading:
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>> String.valueOf(Object) versus Objects.toString(Object) [marxsoftware.blogspot.com]
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>> How to fix the Hibernate “No Dialect mapping for JDBC type” issue [vladmihalcea.com]
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>> Jib, a Java Container Image Builder from Google [infoq.com]
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>> Uber Open Sources JVM Profiler for Tracing Distributed JVMs [infoq.com]
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>> TomEE: Using JCache with CDI [tomitribe.com]
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>> QCon New York 2018: Better Developer Experience at Netflix: Polyglot and Containers [infoq.com]
Time to upgrade:
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>> Hibernate Validator 6.0.13.Final released [in.relation.to]
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>> Spring Security OAuth2 Boot Auto-config 2.0.4 & 2.1.0.M2 Released [spring.io]
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>> Eclipse Releases Versions 1.4 and 2.0 of MicroProfile [infoq.com]
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>> JDK 11: First Release Candidate [mail.openjdk.java.net]
2. Technical and Musings
>> How to extract a data-rich service from a monolith [martinfowler.com]
Another promising series – this installment prescribes a pattern for this task as a series of steps aimed at minimizing disruptions to service consumers. A great approach.
>> Back to basics: Dependency Injection [blog.frankel.ch]
A quick refresher course touts the merits of DI, even as many are questioning its value due to misinformation.
>> Why certificate pinning with HPKP is a bad idea [advancedweb.hu]
A study of HTTP Public Key Pinning — it may sound good at first but comes with unacceptable risks. Steer clear.
>> Orange Code [michaelfeathers.silvrback.com]
An insightful analogy compares — wait for it — apples to oranges, where the apples are monolithic methods, and the oranges are their carefully crafted equivalents, achieved through method extraction.
>> The State of Agile Software in 2018 [martinfowler.com]
A thoughtful write-up outlines some of the challenges that Agile must overcome, such as “faux agile” and the “Agile Industrial Complex”.
>> Transmuting Low-Value Programmer Cred into High-Value Status lllegibility [daedtech.com]
A fascinating look into the dynamics that influence programmer hiring practices.
Also worth reading:
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>> Setting up Netdata monitoring with Slack alarms [blog.arnoldgalovics.com]
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>> Lessons learned after serving thousands of concurrent users in a devops team for a year [vanwilgenburg.wordpress.com]
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>> Setting expectations [dandreamsofcoding.com]
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>> Understanding IoT (Part 1) [blog.codecentric.de]
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>> Understanding IoT (Part 2) [blog.codecentric.de]
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>> Part 2: Scheduling Notebooks at Netflix [medium.com]
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>> The Future of Software Delivery is Code. And It’s Here [the-composition.com]
3. Comics
And my favorite Dilberts of the week:
>> Time Management According to Dogbert [dilbert.com]
>> Wally as a Mentor [dilbert.com]
>> We Like Databases [dilbert.com]
4. Pick of the Week
This week I’ve finally announced the new stuff that’s coming down the pike in my REST With Spring course – all related to Spring Boot 2 and Spring 5.1 (along with the upcoming price change):
