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.

Partner – Microsoft – NPI EA (cat = Baeldung)
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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.

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

Partner – Orkes – NPI EA (cat=Spring)
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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.

Partner – Orkes – NPI EA (tag=Microservices)
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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.

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:

>> 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

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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:

>> 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 – All Access – NPI EA (cat= Spring)
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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
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 – LambdaTest – NPI EA (cat=Testing)
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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:

>> Automated End-to-End Testing With Playwright

Course – Spring Sale 2025 – NPI EA (cat= Baeldung)
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Yes, we're now running our Spring Sale. All Courses are 25% off until 26th May, 2025:

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Course – Spring Sale 2025 – NPI (cat=Baeldung)
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Yes, we're now running our Spring Sale. All Courses are 25% off until 26th May, 2025:

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eBook – Guide Junit – NPI (tag = JUnit)
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Improve your tests with JUnit 5, from mastering the basics to employing the new powerful features from JUnit 5 like extensions, tagging, filtering, parameterized tests, and more:

>> The Junit 5 handbook

1. Overview

JUnit is one of the most popular unit-testing frameworks in the Java ecosystem. The JUnit 5 version contains a number of exciting innovations, with the goal of supporting new features in Java 8 and above, as well as enabling many different styles of testing.

Further reading:

Parallel Test Execution for JUnit 5

In this article, we'll cover how to execute parallel unit tests using JUnit 5.

Using JUnit 5 with Gradle

Learn how to set up and run JUnit 5 tests with Gradle.

Guide to JUnit 5 Parameterized Tests

Learn how to simplify test coverage in JUnit 5 with parameterized tests

2. Maven Dependencies

Setting up JUnit 5.x.0 is pretty straightforward; we just need to add the following dependency to our pom.xml:

<dependency>
    <groupId>org.junit.jupiter</groupId>
    <artifactId>junit-jupiter-engine</artifactId>
    <version>5.11.0-M2</version>
    <scope>test</scope>
</dependency>

Furthermore, there’s now direct support to run Unit tests on the JUnit Platform in Eclipse, as well as IntelliJ. We can, of course, also run tests using the Maven Test goal.

On the other hand, IntelliJ supports JUnit 5 by default. Therefore, running JUnit 5 on IntelliJ is pretty easy. We simply Right click –> Run, or Ctrl-Shift-F10.

It’s important to note that this version requires Java 8 to work.

3. Architecture

JUnit 5 comprises several different modules from three different sub-projects.

3.1. JUnit Platform

The platform is responsible for launching testing frameworks on the JVM. It defines a stable and powerful interface between JUnit and its clients, such as build tools.

The platform easily integrates clients with JUnit to discover and execute tests.

It also defines the TestEngine API for developing a testing framework that runs on the JUnit platform. By implementing a custom TestEngine, we can plug 3rd party testing libraries directly into JUnit.

3.2. JUnit Jupiter

This module includes new programming and extension models for writing tests in JUnit 5. New annotations in comparison to JUnit 4 are:

  • @TestFactory – denotes a method that’s a test factory for dynamic tests
  • @DisplayName – defines a custom display name for a test class or a test method
  • @Nested – denotes that the annotated class is a nested, non-static test class
  • @Tag – declares tags for filtering tests
  • @ExtendWith – registers custom extensions
  • @BeforeEach – denotes that the annotated method will be executed before each test method (previously @Before)
  • @AfterEach – denotes that the annotated method will be executed after each test method (previously @After)
  • @BeforeAll – denotes that the annotated method will be executed before all test methods in the current class (previously @BeforeClass)
  • @AfterAll – denotes that the annotated method will be executed after all test methods in the current class (previously @AfterClass)
  • @Disabled – disables a test class or method (previously @Ignore)

3.3. JUnit Vintage

JUnit Vintage supports running tests based on JUnit 3 and JUnit 4 on the JUnit 5 platform.

4. Basic Annotations

To discuss the new annotations, we divided this section into the following groups responsible for execution: before the tests, during the tests (optional), and after the tests:

4.1. @BeforeAll and @BeforeEach

Below is an example of the simple code to be executed before the main test cases:

@BeforeAll
static void setup() {
    log.info("@BeforeAll - executes once before all test methods in this class");
}

@BeforeEach
void init() {
    log.info("@BeforeEach - executes before each test method in this class");
}

It’s important to note that the method with the @BeforeAll annotation needs to be static, otherwise the code won’t compile.

4.2. @DisplayName and @Disabled

Now let’s move to new test-optional methods:

@DisplayName("Single test successful")
@Test
void testSingleSuccessTest() {
    log.info("Success");
}

@Test
@Disabled("Not implemented yet")
void testShowSomething() {
}

As we can see, we can change the display name or disable the method with a comment, using new annotations.

4.3. @AfterEach and @AfterAll

Finally, let’s discuss the methods connected to operations after test execution:

@AfterEach
void tearDown() {
    log.info("@AfterEach - executed after each test method.");
}

@AfterAll
static void done() {
    log.info("@AfterAll - executed after all test methods.");
}

Please note that the method with @AfterAll also needs to be a static method.

5. Assertions and Assumptions

JUnit 5 tries to take full advantage of the new features from Java 8, especially lambda expressions.

5.1. Assertions

Assertions have been moved to org.junit.jupiter.api.Assertions, and have been significantly improved. As mentioned earlier, we can now use lambdas in assertions:

@Test
void lambdaExpressions() {
    List numbers = Arrays.asList(1, 2, 3);
    assertTrue(numbers.stream()
      .mapToInt(Integer::intValue)
      .sum() > 5, () -> "Sum should be greater than 5");
}

Although the example above is trivial, one advantage of using the lambda expression for the assertion message is that it’s lazily evaluated, which can save time and resources if the message construction is expensive.

It’s also now possible to group assertions with assertAll(), which will report any failed assertions within the group with a MultipleFailuresError:

 @Test
 void groupAssertions() {
     int[] numbers = {0, 1, 2, 3, 4};
     assertAll("numbers",
         () -> assertEquals(numbers[0], 1),
         () -> assertEquals(numbers[3], 3),
         () -> assertEquals(numbers[4], 1)
     );
 }

This means it’s now safer to make more complex assertions, as we’ll be able to pinpoint the exact location of any failure.

5.2. Assumptions

Assumptions are used to run tests only if certain conditions are met. This is typically used for external conditions that are required for the test to run properly, but which aren’t directly related to whatever is being tested.

We can declare an assumption with assumeTrue(), assumeFalse(), and assumingThat():

@Test
void trueAssumption() {
    assumeTrue(5 > 1);
    assertEquals(5 + 2, 7);
}

@Test
void falseAssumption() {
    assumeFalse(5 < 1);
    assertEquals(5 + 2, 7);
}

@Test
void assumptionThat() {
    String someString = "Just a string";
    assumingThat(
        someString.equals("Just a string"),
        () -> assertEquals(2 + 2, 4)
    );
}

If an assumption fails, a TestAbortedException is thrown and the test is simply skipped.

Assumptions also understand lambda expressions.

6. Exception Testing

There are two ways of exception testing in JUnit 5, both of which we can implement using the assertThrows() method:

@Test
void shouldThrowException() {
    Throwable exception = assertThrows(UnsupportedOperationException.class, () -> {
      throw new UnsupportedOperationException("Not supported");
    });
    assertEquals("Not supported", exception.getMessage());
}

@Test
void assertThrowsException() {
    String str = null;
    assertThrows(IllegalArgumentException.class, () -> {
      Integer.valueOf(str);
    });
}

The first example verifies the details of the thrown exception, and the second one validates the type of exception.

7. Test Suites

To continue with the new features of JUnit 5, we’ll explore the concept of aggregating multiple test classes in a test suite, so that we can run those together. JUnit 5 provides two annotations, @SelectPackages and @SelectClasses, to create test suites.

Keep in mind that at this early stage, most IDEs don’t support these features.

Let’s have a look at the first one:

@Suite
@SelectPackages("com.baeldung")
@ExcludePackages("com.baeldung.suites")
public class AllUnitTest {}

@SelectPackage is used to specify the names of packages to be selected when running a test suite. In our example, it will run all tests. The second annotation, @SelectClasses, is used to specify the classes to be selected when running a test suite:

@Suite
@SelectClasses({AssertionTest.class, AssumptionTest.class, ExceptionTest.class})
public class AllUnitTest {}

For instance, the above class will create a suite that contains three test classes. Please note that the classes don’t have to be in one single package.

8. Dynamic Tests

The last topic that we want to introduce is JUnit 5’s Dynamic Tests feature, which allows us to declare and run test cases generated at run-time. Contrary to Static Tests, which define a fixed number of test cases at the compile time, Dynamic Tests allow us to define the test cases dynamically in the runtime.

Dynamic tests can be generated by a factory method annotated with @TestFactory. Let’s have a look at the code:

@TestFactory
Stream<DynamicTest> translateDynamicTestsFromStream() {
    return in.stream()
      .map(word ->
          DynamicTest.dynamicTest("Test translate " + word, () -> {
            int id = in.indexOf(word);
            assertEquals(out.get(id), translate(word));
          })
    );
}

This example is very straightforward and easy to understand. We want to translate words using two ArrayList, named in and out, respectively. The factory method must return a Stream, Collection, Iterable, or Iterator. In our case, we chose a Java 8 Stream.

Please note that @TestFactory methods must not be private or static. The number of tests is dynamic, and it depends on the ArrayList size.

9. Conclusion

In this article, we presented a quick overview of the changes that are coming with JUnit 5.

We explored the big changes to the architecture of JUnit 5 in relation to the platform launcher, IDE, other Unit test frameworks, the integration with build tools, etc. In addition, JUnit 5 is more integrated with Java 8, especially with Lambdas and Stream concepts.

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.
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.

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

Partner – Orkes – NPI EA (cat = Spring)
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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.

Partner – Orkes – NPI EA (tag = Microservices)
announcement - icon

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.

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?

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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

Course – Spring Sale 2025 – NPI EA (cat= Baeldung)
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Yes, we're now running our Spring Sale. All Courses are 25% off until 26th May, 2025:

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Course – Spring Sale 2025 – NPI (All)
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eBook Jackson – NPI EA – 3 (cat = Jackson)