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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.

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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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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.

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

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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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Explore Spring Boot 3 and Spring 6 in-depth through building a full REST API with the framework:

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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.

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

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1. Overview

In this quick tutorial, we’ll focus on how to configure a method call to throw an exception with Mockito.

For more information on the library, also check out our Mockito series.

Here’s the simple dictionary class that we’ll use:

class MyDictionary {
    
    private Map<String, String> wordMap;

    public void add(String word, String meaning) {
        wordMap.put(word, meaning);
    }

    public String getMeaning(String word) {
        return wordMap.get(word);
    }
}

Further reading:

Assert an Exception Is Thrown in JUnit 4 and 5

Have a look at how to test if an exception was thrown using JUnit.

Mockito Support for Optional, Streams, Lambda Expressions

Overview of Java 8 support in Mockito framework, including Streams and default interface methods

AssertJ Exception Assertions

Learn how to use AssertJ for performing assertions on exceptions.

2. Non-Void Return Type

First, if our method return type is not void, we can use when().thenThrow():

@Test
void givenNonVoidReturnType_whenUsingWhenThen_thenExceptionIsThrown() {
    MyDictionary dictMock = mock(MyDictionary.class);
    when(dictMock.getMeaning(anyString())).thenThrow(NullPointerException.class);
    
    assertThrows(NullPointerException.class, () -> dictMock.getMeaning("word"));
}

Notice that we configured the getMeaning() method — which returns a value of type String — to throw a NullPointerException when called.

3. Void Return Type

Now, if our method returns void, we’ll use doThrow():

@Test
void givenVoidReturnType_whenUsingDoThrow_thenExceptionIsThrown() {
    MyDictionary dictMock = mock(MyDictionary.class);
    doThrow(IllegalStateException.class).when(dictMock)
        .add(anyString(), anyString());
    
    assertThrows(IllegalStateException.class, () -> dictMock.add("word", "meaning"));
}

Here, we configured an add() method — which returns void — to throw IllegalStateException when called.

We can’t use when().thenThrow() with the void return type, as the compiler doesn’t allow void methods inside brackets.

4. Exception as an Object

To configure the exception itself, we can pass the exception’s class as in our previous examples or as an object:

@Test
void givenNonVoidReturnType_whenUsingWhenThenAndExeceptionAsNewObject_thenExceptionIsThrown() {
    MyDictionary dictMock = mock(MyDictionary.class);
    when(dictMock.getMeaning(anyString())).thenThrow(new NullPointerException("Error occurred"));
    
    assertThrows(NullPointerException.class, () -> dictMock.getMeaning("word"));
}

And we can do the same with doThrow():

@Test
void givenNonVoidReturnType_whenUsingDoThrowAndExeceptionAsNewObject_thenExceptionIsThrown() {
    MyDictionary dictMock = mock(MyDictionary.class);
    doThrow(new IllegalStateException("Error occurred")).when(dictMock)
        .add(anyString(), anyString());
    
    assertThrows(IllegalStateException.class, () -> dictMock.add("word", "meaning"));
}

5. Spy

We can also configure Spy to throw an exception the same way we did with the mock:

@Test
void givenSpyAndNonVoidReturnType_whenUsingWhenThen_thenExceptionIsThrown() {
    MyDictionary dict = new MyDictionary();
    MyDictionary spy = Mockito.spy(dict);
    when(spy.getMeaning(anyString())).thenThrow(NullPointerException.class);
    
    assertThrows(NullPointerException.class, () -> spy.getMeaning("word"));
}

6. Conclusion

In this article, we explored how to configure method calls to throw an exception in Mockito.

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:

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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 – 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:

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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)