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

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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:

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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:

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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:

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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

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

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

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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:

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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:

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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

In Java development, proper import statements are important in maintaining code readability and avoiding potential conflicts.

IntelliJ IDEA is a popular integrated development environment (IDE) for Java. So, in this quick tutorial, we’ll explore how to disable wildcard imports in IntelliJ.

2. IntelliJ’s Optimize Imports Feature

IntelliJ ships with the “optimize imports” feature, which can automatically rearrange import statements, such as applying a predefined style, adjusting the order, cleaning the unused imports, etc.

We can apply “optimize imports” to the current Java file through the menu item: Code -> Optimize imports:

1 menu code org imports

Of course, we can also optimize imports in the current Java file using shortcuts.

3. The Import Settings in IntelliJ

Wildcard import is a common practice that imports all classes within a package, such as import java.util.*.  Wildcard imports can save keystrokes. However, they may introduce ambiguity and make code harder to understand.

To disable the wildcard import, we open the Settings popup window: File -> Settings (or “Preferences” on macOS).

Then, in the Settings window, we navigate to the Java imports setting tab: Editor -> Code Style -> Java ->Imports:

2 java import settings

Under the “Imports” tab, three settings can affect if IntelliJ will use wildcard imports in the Java file:

3 java import options

Next, let’s take a closer look at them.

4. The General Switch – “Use single class import”

The first checkbox, “Use single class import” is the general switch to specify if we want to enable wildcard import or not in Java source files. If we don’t check this option, IntelliJ always uses wildcard imports.

Let’s say a Java file only has two import statements:

import java.time.Instant;
import java.util.ArrayList;

If we don’t check the “Use single class import” option and let IntelliJ “Optimize Imports” for us. The two imports above turn into this:

import java.time.*;
import java.util.*;

So, we should check the “Use single class import” option if we want to disable wildcard imports in Java source files.

5. The “Class count to use import with ‘*'” Option

Next, let’s look at the “Class count to use import with ‘*’” configuration. We can set the value of this option to a desired number. IntelliJ automatically switches from explicit imports to wildcard imports when the number of imported classes exceeds the given value.

Consider the imports in one of our Java files:

import java.time.Instant;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashSet;
import java.util.Collections;
import java.util.Date;
import java.util.List;
import java.util.function.Supplier;
import java.util.stream.Collectors;
import java.util.stream.IntStream;

Let’s say we have these two settings in IntelliJ:

  • Use single class import” option – Checked
  • Class count to use import with ‘*’” – 5

Now, if we ask IntelliJ to optimize imports automatically, we’ll see the following:

import java.time.Instant;
import java.util.*;
import java.util.function.Supplier;
import java.util.stream.Collectors;
import java.util.stream.IntStream;

As we can see since we have imported more than five classes from the java.util package, the import statements become java.util.*.

So, if we want to disable the wildcard imports, we can set the value of “Class count to use import with ‘*’” to a large number, such as 100 or even 999.

6. Exceptions: the “Packages to Use Imports with ‘*’” Table

Finally, let’s look at the “Packages to Use Imports with ‘*’” table. The table allows us to add packages that always use wildcard imports no matter if we checked the “Use single class import” option or which number we set for the “Class count to use import with ‘*’” configuration.

Let’s say we have the following settings in IntelliJ:

  • Use single class import” option – Checked
  • Class count to use import with ‘*’” – 100
  • “Packages to Use Imports with ‘*”‘java.util.* (with sub-packages)

Now, if we optimize the imports of the Java file in the previous section, we will get the following:

import java.time.Instant;
import java.util.*;
import java.util.function.*;
import java.util.stream.*;

Since we have the “java.util.*” entry in the “Packages to Use Imports with ‘*” table, IntelliJ uses wildcard imports for any classes in the java.util package.

Therefore, the table should be empty if we want to disable wildcard imports completely.

7. Imports Configuration Using .editorconfig File

IntelliJ IDEA allows us to manage all code style settings for different types of files with EditorConfig support.

Create a .editorconfig file in the root directory with the following content:

[*.java] 
ij_java_use_single_class_imports = true 
ij_java_class_count_to_use_import_on_demand = 100 
ij_java_names_count_to_use_import_on_demand = 100 
ij_java_packages_to_use_import_on_demand = java.awt.*,javax.swing.*

Now, when you use IntelliJ IDEA’s Optimize Imports feature, the imports in .java files will be optimized according to this configuration.

8. Conclusion

In this article, we’ve discussed how to set three main configuration options to disable wildcard imports in Java files in IntelliJ completely:

  • Use single class import” option – Check the option
  • Class count to use import with ‘*’” – 100 (or 999)
  • Packages to Use Imports with ‘*’ – Leave this table empty
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)