Java Weekly, Issue 192
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:
Handling concurrency in an application can be a tricky process with many potential pitfalls. A solid grasp of the fundamentals will go a long way to help minimize these issues.
Get started with understanding multi-threaded applications with our Java Concurrency 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.
Distributed systems often come with complex challenges such as service-to-service communication, state management, asynchronous messaging, security, and more.
Dapr (Distributed Application Runtime) provides a set of APIs and building blocks to address these challenges, abstracting away infrastructure so we can focus on business logic.
In this tutorial, we'll focus on Dapr's pub/sub API for message brokering. Using its Spring Boot integration, we'll simplify the creation of a loosely coupled, portable, and easily testable pub/sub messaging system:
Lots of interesting writeups on Java 9 this week.
Here we go…
1. Spring and Java
>> How To Map The Date And Time API with JPA 2.2 [thoughts-on-java.org]
Support for the new Date/Time API for Java finally comes along with the JPA 2.2.
>> @Contended @since 9 [javaspecialists.eu]
Java 9 will be trying to encapsulate internal system classes that we should not be using (but we often are).
The @Contended annotation is one of those tools – let’s see how we can access it in Java 9.
>> You’re not a compiler! [frankel.ch]
Programming quizzes are cool, but obviously, they do test a very thin slice of developer’s skills.
All in all, not that useful.
>> Planning Your Java 9 Update [codefx.org]
Java 9 is coming soon (hopefully) and brings a host of new APIs and language features, modules among them.
Modularizing an application should be well thought and carefully planned.
>> Java API for RESTful Web Services 2.1 Released [infoq.com]
JAX-RS 2.1 finally got released and has a bunch of cool new features.
>> Code Smells: Mutation [blog.jetbrains.com]
Simply put – it’s a bad idea to mutate something you’re directly iterating over 🙂
>> JUnit 5 Tutorial: Running Unit Tests With Gradle [petrikainulainen.net]
Running JUnit 5 tests might be slightly tricky in certain scenarios – it’s important to remember that JUnit 5 is split into a few different artifacts you can leverage separately.
>> Cost Reduction Strategies on Java Cloud Hosting Services [infoq.com]
Cloud resources can be expensive, especially when you’re forced to pay for resources that you don’t need.
Here are a few techniques to make sure you’re paying only for what you actually use.
>> Idiomatic Peeking with Java Stream API [4comprehension.com]
Multiple controversies are surrounding the peek() method from the Java Stream API – here you can see what those are and how to use the method properly.
Also worth reading:
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>> Dynamically adding an interceptor to a built-in CDI bean [arjan-tijms.omnifaces.org]
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>> JUnit 5 Tutorial: Running Unit Tests With Maven [petrikainulainen.net]
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>> Hibernate Tips: How to delete child entities from a many-to-one association [thoughts-on-java.org]
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>> The best way to map a projection query to a DTO (Data Transfer Object) with JPA and Hibernate [vladmihalcea.com]
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>> Localization of Spring Security Error Messages in Spring Boot [codecentric.de]
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>> First Vavr Tutorial [blog.vavr.io]
Webinars and presentations:
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>> Spring Cloud Data Flow Tips & Tricks: Interacting with the Shell [spring.io]
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>> What Does Speed Mean in Software Product Delivery? [infoq.com]
Time to upgrade:
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>> Bugfix releases for Hibernate Search 5.5, 5.6 and 5.7 [in.relation.to]
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>> jOOQ 3.10 Supports JPA AttributeConverter [jooq.org]
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>> IntelliJ IDEA 2017.2: Smarter, Neater, and Faster [infoq.com]
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>> IntelliJ IDEA 2017.2: Spring Boot Improvements [jetbrains.com]
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>> Spring Cloud Edgware M1 Is Now Available [spring.io]
2. Technical
>> Stability in a Chaotic World: How Postgres Makes Transactions Atomic [brandur.org]
A super deep-dive into the internal of Postgres.
Also worth reading:
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>> Selecting an Event Architecture [infoq.com]
3. Musings
>> Scale Your Freelancing: Hiring Others [daedtech.com]
Well, you should probably start by finding a good lawyer and an accountant – that holds true for pretty much every country 🙂
Also worth reading:
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>> Reinforcement Learning Overview [horicky.blogspot.com]
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>> How To Handle Business Rules in Domain Driven Design [blog.sapiensworks.com]
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>> When do you cut your Losses? [offbeattesting.com]
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>> The Web in 2050 [jacquesmattheij.com]
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>> Just Following Orders [blog.cleancoder.com]
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>> Spring Cleaning Your Code Review [daedtech.com]
4. Comics
And my favorite Dilberts of the week:
>> Small Talk [dilbert.com]
>> Complaining pill [dilbert.com]
>> Fool-proof plan for success [dilbert.com]
5. Pick of the Week
The last day (Friday) of the REST With Spring 2.0 launch:
