eBook – Guide Spring Cloud – NPI EA (cat=Spring Cloud)
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Let's get started with a Microservice Architecture with Spring Cloud:

>> Join Pro and download the eBook

eBook – Mockito – NPI EA (tag = Mockito)
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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:

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eBook – Java Concurrency – NPI EA (cat=Java Concurrency)
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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:

>> Download the eBook

eBook – Reactive – NPI EA (cat=Reactive)
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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:

>> Join Pro and download the eBook

eBook – Java Streams – NPI EA (cat=Java Streams)
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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:

>> Join Pro and download the eBook

eBook – Jackson – NPI EA (cat=Jackson)
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Do JSON right with Jackson

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eBook – HTTP Client – NPI EA (cat=Http Client-Side)
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Get the most out of the Apache HTTP Client

Download the E-book

eBook – Maven – NPI EA (cat = Maven)
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Get Started with Apache Maven:

Download the E-book

eBook – Persistence – NPI EA (cat=Persistence)
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Working on getting your persistence layer right with Spring?

Explore the eBook

eBook – RwS – NPI EA (cat=Spring MVC)
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Building a REST API with Spring?

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Course – LS – NPI EA (cat=Jackson)
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Get started with Spring and Spring Boot, through the Learn Spring course:

>> LEARN SPRING
Course – RWSB – NPI EA (cat=REST)
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Explore Spring Boot 3 and Spring 6 in-depth through building a full REST API with the framework:

>> The New “REST With Spring Boot”

Course – LSS – NPI EA (cat=Spring Security)
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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:

>> Learn Spring Security

Course – LSD – NPI EA (tag=Spring Data JPA)
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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:

>> CHECK OUT THE COURSE

Partner – Moderne – NPI EA (cat=Spring Boot)
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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.

Course – LJB – NPI EA (cat = Core Java)
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Code your way through and build up a solid, practical foundation of Java:

>> Learn Java Basics

1. Overview

IntelliJ IDEA relies heavily on indexing to deliver its intelligent features. Every time files are modified or opened, IntelliJ scans the project files to build an internal index. This allows the IDE to provide faster code lookups and accurate code analysis. While useful, frequent indexing can consume a significant amount of resources and hinder productivity, especially in large codebases.

Fortunately, there are several ways to stop, limit, or optimize the indexing process in IntelliJ IDEA. In this article, we’ll explore practical tips and techniques to manage IntelliJ IDEA’s indexing more efficiently.

2. Understand the Role of Indexing in IntelliJ IDEA

Indexing is a fundamental process in IntelliJ IDEA that involves scanning and analyzing the project’s source code to create an internal database. This database stores detailed information about code elements such as classes, methods, and variables.

The indexing process in IntelliJ IDEA works as follows:

  • Code Scanning: IntelliJ scans the project’s files and extracts information about symbols and code structures.
  • Database Creation: The extracted data is stored in an internal index, which the IDE uses to provide features like code completion, navigation, and search.
  • Updates and Re-Indexing: The index is updated whenever there are changes to the codebase, such as modifications or additions. This ensures that the IDE’s features reflect the project’s current state.

While indexing is essential for enabling IntelliJ’s advanced features, it can consume significant system resources and time, especially in large projects. By understanding how indexing works, we can implement strategies to manage its impact, balancing performance with the IDE’s powerful capabilities.

3. Disable Synchronization on Frame or Tab Activation

IntelliJ IDEA automatically synchronizes and re-indexes files whenever we switch back to the IDE from another application or move between editor tabs. This can result in frequent and often unnecessary re-indexing that may disrupt our workflow.

Here are the steps to prevent this automatic behavior:

  • Navigate to “File > Settings > Appearance & Behavior > System Settings”.
  • Uncheck the “Synchronize external changes when switching to the IDE window or opening an editor tab” option.
Disable synchronization on Frame or Tab activation

Disabling this setting stops IntelliJ from triggering an index update when we return to the IDE or change tabs. This allows us to control when to refresh and re-index the project manually, helping to minimize interruptions and improve overall efficiency.

4. Exclude Unnecessary Folders From Indexing

One of the most effective ways to limit indexing is by excluding folders that don’t need to be part of the index. Large folders such as build or logs don’t typically require indexing for IntelliJ to function correctly.

To exclude folders from indexing:

  • Right-click on the folder in the project view.
  • Select “Mark Directory as > Excluded”.
Exclude unnecessary files from Indexing

Excluding a folder from the indexing process reduces the number of files IntelliJ needs to scan, which speeds up indexing and minimizes its impact on performance.

5. Adjust Project Reload Settings

In large projects, particularly those using external build tools like Maven or Gradle, IntelliJ IDEA can automatically reload and re-index files whenever it detects changes in the build script. This mechanism can disrupt our workflow and affect performance. By adjusting this setting, we can gain more control over when the IDE updates and re-indexes the project.

To configure automatic project reload:

  • Go to “File > Settings > Build, Execution, Deployment > Build Tools”.
  • Locate the “Reload project after changes in the build scripts” option”.
  • Choose the appropriate setting:
    • Any changes: Automatically reloads the project after every change in the build script files.
    • External changes (default): Reloads the project only when changes are detected from external sources, such as updates from version control. This prevents reloading after every minor change and allows us to control when to refresh the project.
Adjust roject reload settings

Selecting the “External changes” option ensures that the project isn’t reloaded unnecessarily, reducing the indexing frequency and allowing us to manage updates more effectively.

6. Invalidate Cache Only When Necessary

Occasionally, IntelliJ IDEA may experience issues with repeated indexing due to corrupted or outdated caches. In such cases, invalidating the cache can help resolve problems caused by stale or erroneous data, although it triggers a complete re-index.

To invalidate the cache:

  • Go to “File > Invalidate Caches / Restart”.
  • Choose “Invalidate and Restart”.
Invalidate cache only when necessary

This action forces IntelliJ to rebuild its index from scratch, which can address issues with persistent or excessive indexing. However, since this process can be time-consuming and disrupt our workflow, it should be used sparingly and only when other methods haven’t resolved the problem.

7. Conclusion

Indexing is crucial for IntelliJ IDEA’s advanced features but can be disruptive if overly frequent. By disabling automatic synchronization, excluding unnecessary folders, adjusting project reload settings, and using cache invalidation sparingly, we can effectively manage IntelliJ IDEA’s indexing cycle.

These steps help balance the IDE’s powerful capabilities with a smoother development experience.

Baeldung Pro – NPI EA (cat = Baeldung)
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Baeldung Pro comes with both absolutely No-Ads as well as finally with Dark Mode, for a clean learning experience:

>> Explore a clean Baeldung

Once the early-adopter seats are all used, the price will go up and stay at $33/year.

eBook – HTTP Client – NPI EA (cat=HTTP Client-Side)
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The Apache HTTP Client is a very robust library, suitable for both simple and advanced use cases when testing HTTP endpoints. Check out our guide covering basic request and response handling, as well as security, cookies, timeouts, and more:

>> Download the eBook

eBook – Java Concurrency – NPI EA (cat=Java Concurrency)
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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:

>> Download the eBook

eBook – Java Streams – NPI EA (cat=Java Streams)
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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:

>> Join Pro and download the eBook

eBook – Persistence – NPI EA (cat=Persistence)
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Working on getting your persistence layer right with Spring?

Explore the eBook

Course – LS – NPI EA (cat=REST)

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Get started with Spring Boot and with core Spring, through the Learn Spring course:

>> CHECK OUT THE COURSE

Partner – Moderne – NPI EA (tag=Refactoring)
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Modern Java teams move fast — but codebases don’t always keep up. Frameworks change, dependencies drift, and tech debt builds until it starts to drag on delivery. OpenRewrite was built to fix that: an open-source refactoring engine that automates repetitive code changes while keeping developer intent intact.

The monthly training series, led by the creators and maintainers of OpenRewrite at Moderne, walks through real-world migrations and modernization patterns. Whether you’re new to recipes or ready to write your own, you’ll learn practical ways to refactor safely and at scale.

If you’ve ever wished refactoring felt as natural — and as fast — as writing code, this is a good place to start.

eBook Jackson – NPI EA – 3 (cat = Jackson)