Baeldung Pro comes with both absolutely No-Ads as well as finally with Dark Mode, for a clean learning experience:
Once the early-adopter seats are all used, the price will go up and stay at $33/year.
Azure Container Apps is a fully managed serverless container service that enables you to build and deploy modern, cloud-native Java applications and microservices at scale. It offers a simplified developer experience while providing the flexibility and portability of containers.
Of course, Azure Container Apps has really solid support for our ecosystem, from a number of build options, managed Java components, native metrics, dynamic logger, and quite a bit more.
To learn more about Java features on Azure Container Apps, visit the documentation page.
You can also ask questions and leave feedback on the Azure Container Apps GitHub page.
Azure Container Apps is a fully managed serverless container service that enables you to build and deploy modern, cloud-native Java applications and microservices at scale. It offers a simplified developer experience while providing the flexibility and portability of containers.
Of course, Azure Container Apps has really solid support for our ecosystem, from a number of build options, managed Java components, native metrics, dynamic logger, and quite a bit more.
To learn more about Java features on Azure Container Apps, you can get started over on the documentation page.
And, you can also ask questions and leave feedback on the Azure Container Apps GitHub page.
Modern software architecture is often broken. Slow delivery leads to missed opportunities, innovation is stalled due to architectural complexities, and engineering resources are exceedingly expensive.
Orkes is the leading workflow orchestration platform built to enable teams to transform the way they develop, connect, and deploy applications, microservices, AI agents, and more.
With Orkes Conductor managed through Orkes Cloud, developers can focus on building mission critical applications without worrying about infrastructure maintenance to meet goals and, simply put, taking new products live faster and reducing total cost of ownership.
Try a 14-Day Free Trial of Orkes Conductor today.
Modern software architecture is often broken. Slow delivery leads to missed opportunities, innovation is stalled due to architectural complexities, and engineering resources are exceedingly expensive.
Orkes is the leading workflow orchestration platform built to enable teams to transform the way they develop, connect, and deploy applications, microservices, AI agents, and more.
With Orkes Conductor managed through Orkes Cloud, developers can focus on building mission critical applications without worrying about infrastructure maintenance to meet goals and, simply put, taking new products live faster and reducing total cost of ownership.
Try a 14-Day Free Trial of Orkes Conductor today.
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:
All Access is finally out, with all of my Spring courses. Learn JUnit is out as well, and Learn Maven is coming fast. And, of course, quite a bit more affordable. Finally.
>> GET THE COURSE
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:
End-to-end testing is a very useful method to make sure that your application works as intended. This highlights issues in the overall functionality of the software, that the unit and integration test stages may miss.
Playwright is an easy-to-use, but powerful tool that automates end-to-end testing, and supports all modern browsers and platforms.
When coupled with LambdaTest (an AI-powered cloud-based test execution platform) it can be further scaled to run the Playwright scripts in parallel across 3000+ browser and device combinations:
Yes, we're now running our Spring Sale. All Courses are 25% off until 26th May, 2025:
Yes, we're now running our Spring Sale. All Courses are 25% off until 26th May, 2025:
1. Overview
One of the challenges of unit testing is mocking private methods.
In this tutorial, we’ll learn about how we can achieve this by using the PowerMock library – which is supported by JUnit and TestNG.
PowerMock integrates with mocking frameworks like EasyMock and Mockito and is meant to add additional functionality to these – such as mocking private methods, final classes, and final methods, etc.
It does that by relying on bytecode manipulation and an entirely separate classloader.
2. Maven Dependencies
First, let’s add required dependencies to use PowerMock with Mockito and JUnit into our pom.xml:
<dependency>
<groupId>org.powermock</groupId>
<artifactId>powermock-module-junit4</artifactId>
<version>1.7.3</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.powermock</groupId>
<artifactId>powermock-api-mockito2</artifactId>
<version>2.0.9</version>
<scope>test</scope>
</dependency>The latest versions can be checked here and here.
3. Example
Let’s get started with an example of a LuckyNumberGenerator. This class has a single public method for generating a lucky number:
public int getLuckyNumber(String name) {
saveIntoDatabase(name);
if (name == null) {
return getDefaultLuckyNumber();
}
return getComputedLuckyNumber(name.length());
}4. Variations in Mocking of Private Methods
For exhaustive unit testing of the method, we’d need to mock private methods.
4.1. Method With No Arguments but With Return Value
As a simple example, let’s mock the behavior of a private method with no arguments and force it to return the desired value:
LuckyNumberGenerator mock = spy(new LuckyNumberGenerator());
when(mock, "getDefaultLuckyNumber").thenReturn(300);
In this case, we mock the private method getDefaultLuckyNumber and make it return a value of 300.
4.2. Method With Argument and Return Value
Next, let’s mock the behavior of a private method with an argument and force it to return the desired value:
LuckyNumberGenerator mock = spy(new LuckyNumberGenerator());
doReturn(1).when(mock, "getComputedLuckyNumber", ArgumentMatchers.anyInt());
In this case, we mock the private method and make it return 1.
Notice that we don’t care about the input argument and use ArgumentMatchers.anyInt() as a wildcard.
4.3. Verification of Invocation of a Method
Our final strategy is to use PowerMock to verify the invocation of a private method:
LuckyNumberGenerator mock = spy(new LuckyNumberGenerator());
int result = mock.getLuckyNumber("Tyranosorous");
verifyPrivate(mock).invoke("saveIntoDatabase", ArgumentMatchers.anyString());
5. A Word of Caution
Finally, although private methods can be tested using PowerMock, we must be extra cautious while using this technique.
Given the intent of our testing is to validate the behavior of a class, we should refrain from changing the internal behavior of the class during unit testing.
Mocking techniques should be applied to the external dependencies of the class and not to the class itself.
If mocking of private methods is essential for testing our classes, it usually indicates a bad design.
6. Conclusion
In this quick article, we showed how PowerMock could be used to extend the capability of Mockito for mocking and verification of private methods in the class under test.
The code backing this article is available on GitHub. Once you're logged in as a Baeldung Pro Member, start learning and coding on the project.
