Java Streams Series
Last updated: March 17, 2025
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.
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:
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:
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Stream Basics
- The Java Stream API Tutorial
- Introduction to Java Streams
- Java Stream findFirst() vs. findAny()
- Functional Interfaces in Java
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Stream Collectors
- Guide to Java Collectors
- Guide to Java groupingBy Collector
- Collect a Java Stream to an Immutable Collection
- Java Collectors toMap
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Operations with Streams
- How to Break from Java Stream forEach
- Filtering a Stream of Optionals in Java
- Custom Thread Pools in Java Parallel Streams
- Merging Streams in Java
- The Difference Between map() and flatMap()
- String Operations with Java Streams
- How to Iterate Over a Stream With Indices
- Iterable to Stream in Java
- How to Get the Last Element of a Stream in Java?
- Converting String to Stream of chars
- “Stream has already been operated upon or closed” Exception in Java
- Java and Infinite Streams
- How to Add a Single Element to a Stream
- Primitive Type Streams in Java
- DistinctBy in the Java Stream API
- Introduction to Spliterator in Java
- How to Use if/else Logic in Java Streams
- Java Predicate Chain
- Java Stream Filter with Lambda Expression
- Summing Numbers with Java Streams
- Java Streams peek() API
- Working With Maps Using Streams
- Guide to Stream.reduce()
- When to Use a Parallel Stream in Java
- Java Stream skip() vs limit()
- Collecting Stream Elements into a List in Java
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Java 8 Streams with Other Tools
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