JUnit 4 allows us to implement. Using Matchers. public PowerMockRule rule = new PowerMockRule (); And when we use plugin to convert, it will become. 이 Annotation들을 사용하면 더 적은 코드로 테스트 코드를 작성할 수 있습니다. tried this today, using the @InjectMocks, but it appears to have the same issue, the mock is over-written when it lazily loads the rest of the services. length; } As per listFiles () documentations it should contain the directory, otherwise it will return you null. B () has to be mocked. Learn about how you can use @InjectMocks to automatically add services to classes as they are tested with Mockito. I am getting NullPointerException for authenticationManager dependency. 1 Answer. x), you can't change this behaviour as far as I'm aware, so the only solution is to inject the fields by yourself in a @SetUp method: private ValidateRulesService. You can use MockitoJUnitRunner instead of MockitoAnnotations. Since the MainClass is being used to be mockStatic and injectMock, when calling buildURI, it always return null, which is not acceptable when creating HttpRequest. x (this is the default when using Spring boot 1. Mockito @InjectMocks Annotation. INSTANCE, vendorRepository); I wanted to extend my learning by trying to create an endpoint for getting all vendors. @InjectMocks also creates the mock implementation of annotated type and injects the dependent mocks into it. Use this annotation on your class under test and Mockito will try to inject mocks either by constructor injection, setter injection, or property injection. class, Answers. Field injection ; mocks will first be resolved by type (if a single type match injection will happen regardless of the name), then, if there is several property of the same type, by the match of the field. 4. @Mock создает насмешку. public class BirthDayTest { @Mock private Dependency dependency ; @InjectMock private BirthDay brithday; } So, you should assume that your mock returns some data that you need. This doesn't work well for me, because my mocked mapToMock is actually injected into dontMockMe via its setter. In this style, it is typical to mock all dependencies. Add the dependencies with androidTestImplementation "org. You are combining plain mockito ( @Mock, @InjectMocks) with the spring wrappers for mockito ( @MockBean ). See the revised code:I'm working to test (via JUnit4 and Spring MockMvc) a REST service adapter using Spring-boot. Overview In this tutorial, we’ll discuss how to use dependency injection to insert Mockito mocks into Spring Beans for unit testing. How To Use @InjectMocks For A Dependency For Another Class To Be Mocked? 12 @InjectMocks, the constructor or the initialization block threw an exception. 2. 2. jupiter. 2. save (customer. You. class) // Static. @Mock用于创建用于支持测试类的测试所需的模拟。. @InjectMocks specifically indicates that the annotated field will NOT contain a mock. e. managerLogString(); At mean time, I am able to get correct "UserInput" value for below mockito verify. Mocks can be created and initialized by: Manually creating them by calling the Mockito. And had /@Mock on whats equivalent to Do, so my mocking and injectMocking was backward. The second issue is that your field is declared as final, which Mockito will skip when injecting mocks/spies. My mistake was I had the /@InjectMocks on what is equivalent to ABC on my actual code, therefore, it was trying to create an instance of an interface that was throwing me off. threadPoolSize can't work there, because you can't stub a field. Like other annotations, @Captor. The problem is with your @InjectMocks field. See moreMockito @InjectMocks annotations allow us to inject mocked dependencies in the annotated class mocked object. If you are not able to do that easily, you can using Springs ReflectionTestUtils class to mock individual objects in your service. toString ()) execute it does NOT trigger my MockDao return statement, but instead tries to evaluate someObject. Fields annotated with @Mock will then automatically be initialized with a mock instance of their type, just like as we would call Mockito. In my test class i have this code: @RunWith (MockitoJUnitRunner. int b = 12; boolean c = application. I think there is a bit of confusion and is not clear enough what you what to do. PowerMock, as mentioned in comments to your question), or b) extract call to DBUserUtils. @Mock creates a mock. JUnit特有のアノテーション The @InjectMocks marks a field on which injection should be performed. 7 Tóm lược. 1 Answer. Mockito는 Java에서 인기있는 Mocking framework입니다. Mockito @InjectMocks annotations allow us to inject mocked dependencies in the annotated class mocked object. java @Override public String getUseLanguage() { return applicationProperties. Setter Methods Based – When a Constructor is not there, Mockito tries to inject using property setters. Cause: the type 'UserService' is an interface. @InjectMocks annotation tells to Mockito to inject all mocks (objects annotated by @Mock annotation) into fields of testing object. This Companion class would have only getters for the fields declared (in your case getApi()). 🕘Timestamps:0:10 - Introduction💛. Việc khai báo này sẽ giúp cho chúng ta có thể inject hết tất cả các đối tượng được khai báo với annotation @Mock trong. In the majority of cases there will be no difference as Mockito is designed to handle both situations. . The modularity of the annotation engine, the use of the Reflection API, the injection strategies: how Mockito works internally can be an inspiration for any developer. spy (class) to mock a specific method): PowerMockito. While I didn't explored your project's ins and outs, I believe you might. I don't think I understand how it works. 1. Sorted by: 13. Sorted by: 5. –Nov 17, 2015 at 11:34. @Spy @InjectMocks private MySpy spy; Because InjectMocks need to have instance created, so the solution works for me is at below, @Spy @InjectMocks private MySpy. @InjectMocks @InjectMocks라는 어노테이션이 존재하는데, @Mock이 붙은 목객체를 @InjectMoc. Furthermore you have to use @BeforeEach instead of @Before (See also the migration section in the user guide). 10. Teams. deleteX() is calling init() before finishing - how can i skip this call in my test, because every time i just get a NullPointer Exception. The issue was resolved. public class UserResourceTest { UserResource userResource; @BeforeMethod void beforeMethod () { userResource = new UserResource (); } @Test public void test () { User user= mock (User. class) or @ExtendWith but you are hiding that for whatever reasons). Then the someShimmedMethod will return null. mockito. class, nodes); // or whatever equivalent methods are one. I have a situation where I have a @Component-annotated Spring Boot class that gets @Autowired with all its dependencies (the beans are defined in a @Configuration-annotated config class): @Configuration public class SomeConfig { @Bean public List<Fizz> fizzes() { Fizz fizz = new Fizz(/*complex. Sorted by: 0. Investigations. 4. 1. If you are mocking a Service using @InjectMocks you need to make sure you need to return the value Service. @InjectMocks wasn't really developed to work with other dependency injection frameworks, as the development was driven by unit test use cases, not integration tests. It seems the InjectMocks could not carry the mock () to private member. For those of you who never used. Improve this question. Mockito Extension. I have moved the object creation in "@Before" method and it works now. Note 2: If @InjectMocks instance wasn't initialized before and have a no-arg constructor, then it will be initialized with this constructor. Annotating @InjectMocks @Mock is not just unsupported—it's contradictory. The most widely used annotation in Mockito is @Mock. Perform the injection by hand. Before we go further, let’s recap how we can extend basic JUnit functionality or integrate it with other libraries. My expectation was that since I am using @InjectMocks, and since ProcessorFactory has its constructor autowired, the constructor would be called by InjectMocks as part of the initialization. 3. get ()) will cause a NullPointerException because myService. I did "new Filter()" inside my test method which was not injecting request reference. Initializing a mock object internals before injecting it with @InjectMocks. @InjectMock fails silently for static and final fields and when failing, it doesn't inject other mocks as well. Mockito 라이브러리에서 @Mock 등의 Annotation들을 사용하려면 설정이 필요합니다. g. To mock DBUserUtils. It will create a mock and Spring's normal injection mechanism will inject it into your Bean. Since @InjectMocks will choose the biggest constructor and work on private or package-private constructors, one option would be to add a constructor overload: class PriceSetter { private Table priceTable; public PriceSetter(Dependency d1, Dependency d2) { this(d1, d2, new DefaultPriceTable()); } PriceSetter(Dependency d1, Dependency d2,. CALLS_REAL_METHODS) private. So there was still no clean up of the ApplicationContext. spy (new BBean ()); Full test code: 次に、@InjectMocksアノテーションを使用して、テスト対象のオブジェクトにモックフィールドを自動的に挿入する方法について説明します。 次の例では、 @InjectMocks を使用してモック wordMap を MyDictionary dic に注入します。 @RunWith(MockitoJUnitRunner. You should use a getter there:You will need to initialize the DataMigrationService field when using the @InjectMocks annotation. Mockito will try to inject your mock identity through constructor injection, setter injection, or property. ・モック化したいフィールドに @Mock をつける。. 412. there are a pair of things in your code which not used correctly. I'm facing the issue of NPE for the service that was used in @InjectMocks. 4. キレイでシンプルなAPIでモックを扱うテストコードを記述. Note that @InjectMocks can also be used in combination with the @Spy annotation, it means that Mockito will inject mocks into the partial mock. ここではmock化したクラスに依存しているテスト対象のクラスを取り扱います。 今回はfcというインスタンス変数でインスタンスを宣言しています。 @Before. This is what I have done using Mockito and Powermockito: @InjectMocks ClassBeingTested testObject; @Mock ClassB objectB; @Mock ClassC objectC; @Before () public void setup () { when (objectB. Parameterized. get ("key")); } When MyDictionary. 0. It is used with the Mockito's verify() method to get the values passed when a method is called. However, there is some differences which I have outlined below. 2. standaloneSetup will not do it for you. Ranking. セッタータインジェクションの. How to use @InjectMocks and initMocks() with an object that has a required String parameter? 0. – Zipper. The following works for me: public abstract class Parent { @Mock Message message; @Before public void initMocks () { MockitoAnnotations. But if you want to create a Spring Boot integration test then you should use @MockBean instead of @Mock and @Autowired instead of @InjectMocks. In above example, initMocks () is called in @Before (JUnit4) method of test's base class. @InjectMocks：创建一个实例，其余用@Mock（或@Spy）注解创建的mock将被注入到用该实例中。. @RunWith (MockitoJUnitRunner. Call PowerMockito. Check out this tutorial for even more information, although you. First of all, let’s create a Maven project and add JUnit and Mockito dependencies in the pom. Service. Using @Mock with @InjectMock. For example, consider an EmailService class with a send method that we’d like to test: public class EmailService { private. 如何使Mockito的注解生效. In this tutorial, we’ll compare two JUnit runners – SpringRunner and MockitoJUnitRunner. Mockito - how to inject final field marked as @Mock by constructor when using @Spy and @InjectMocks. Teams. Mockito will try to inject mocks only either by constructor injection, setter injection, or property injection – in this order. This will ensure it is picked up by the component scan in your Spring boot configuration. We can use @Mock to create and inject mocked instances without having to call Mockito. Jan 15, 2014 at 14:15. jar. Spring Boot Mockito's @Mock and @InjectMock Example of Testing Service Layer. spy (new BBean ()); Full test code:次に、@InjectMocksアノテーションを使用して、テスト対象のオブジェクトにモックフィールドを自動的に挿入する方法について説明します。 次の例では、 @InjectMocks を使用してモック wordMap を MyDictionary dic に注入します。@Mock private XyzService xyzService; @InjectMocks private AbcController abcController; @BeforeMethod public void setup(){ MockitoAnnotations. Caused by: org. class) или. First, we’ll examine the different setup options. 이 글에서는 Mockito의 Annotation, @Mock, @Spy, @Captor, @InjectMocks를 사용하는 방법에 대해서 알아봅니다. I am using latest Springboot for my project. Citi India has transferred ownership of its consumer banking business to Axis Bank (registration. You have to use an Extension and annotate the test class or method with ExtendWith. initMocks(this). The @InjectMocks immediately calls the constructor with the default mocked methods. public class IntegrationTest { MockMvc mockMvc; MyService service; Controller controller; @Mock Client client; @Autowired Factory factory; @Before public void setup () { initMocks (this. The rules around which will be chosen are quite complicated, which is one reason why I try to avoid using @InjectMocks whenever possible. However, there is some method might. 2) Adding MockitoAnnotations. Then, (since you are using SpringJUnit4ClassRunner. @DaDaDom, this is not about mocking static methods, but injecting mocks into static objects. You haven't provided the instance at field declaration so I tried to construct the instance. class) public class MockitoAnnotationTest {. 2. If I understand correctly, annotating an object with @Mock will be mocked, @Spy will use a real object, and. Hope that helps6. @InjectMocks DataMigrationService dataMigrationService = new DataMigrationService (); Thank You @Srikanth, that was it. Use @InjectMocks when the actual method body needs to be executed for a given class. Creating the class by hand solves the NullPointerException and the test runs successfully1 Answer. The following sample code shows how @Mock and @InjectMocks works. What I want to do is form an InjectMock, but this injectmock is object is constructed using parameters. We can configure/override the behavior of a method using the same syntax we would use with a mock. I always get null pointer exception for aerospikeClientthe problem is the @InjectMocks and @Spy annotation. これらのアノテーションを利用することで、Autowiredされるクラスの状態をモックオブジェクトで制御することができるようになり、単体テストや下位層が未完成あるいはテストで呼び出されるべきではない場合などに役立ちます。. 2 Answers. From MockitoExtension 's JavaDoc: In this post, We will learn about @InjectMocks Annotation in Mockito with Example. 0 to test full link code in my business scene so I find a strange situation when I initialize this testing instance using @Injectmocks with. val rule = PowerMockRule () Then, even the property was set to be public, you will get compile error, ValidationError: The @Rule 'rule' must be public. It needs concrete class to work with. JUnit 5 has a powerful extension model and Mockito recently published one under the group / artifact ID org. initMocks (this) If you don't want to use MockitoAnnotations. } 方法2：在初始化方法中使用MockitoAnnotations. println ("A's method called"); b. class) public interface MappingDef { UserDto userToUserDto (User user) } this is my nested. managerLogString method (method of @InjectMocks ArticleManager class). But then I read that instead of invoking mock ( SomeClass . junit. However, I can make my test pass when I make a direct call in the setup() vendorService = new VendorServiceImpl(VendorMapper. The @InjectMocks annotation is available in the org. To return stubs wherever possible, use this: @Mock (answer=Answers. @RunWith(MockitoJUnitRunner. MockitoException: Cannot instantiate @InjectMocks field named 'configurationManager'. The only difference. class); one = Mockito. mock; import static org. I looked at the other solutions, but even after following them, it shows same. willReturn() structure provides a fixed return value for the method call. So for your case to work you have to do following change @Mock private OrderIF order; @InjectMocks private ServiceImpl reqService; The easiest way of creating and using mocks is via the @Mock and @InjectMocks annotations. stub the same method more than once, to change the behaviour of. Using them together does not make sense (as discussed in this stackoverflow post). Share. @InjectMocks creates an instance of the class and injects the mocks that are created with the @Mock (or @Spy) annotations into this instance. class). threadPoolSize can't work there, because you can't stub a field. @InjectMocks can be avoided if constructor or setter injection is used. my service class : @Service public class BarcodeReaderService { @Autowired ImageProcessor imageProcessor; public String dummy (String name) { System. 4. Difference between @Mock and @InjectMocks. JUnit 5 has a powerful extension model and Mockito recently published one under the group / artifact ID org. 有三种方式做这件事。. 4. @ExtendWith (MockitoExtension. Add a comment. However, when I run the test it throws a NullPointerException in the line where I am trying to mock the repository findById () method. 2022年11月6日 2022年12月25日. setField(bean, "fieldName", "value"); before invoking your bean method during test. initMocks) could be used when you have already configured a specific runner ( SpringJUnit4ClassRunner for example) on your test case. junit. So remove mocking. Use the MockitoRule public class MockitoTest { @Mock private IRoutingObjHttpClient. It really depends on GeneralConfigService#getInstance () implementation. Add a comment. @InjectMocks creates an instance of the class and injects the mocks that are created with the @Mock (or @Spy) annotations into this instance. The processorCache is zero-length because the constructor is never called. mock () this is good one as an addition, if you are using SpringBoot then preferred to use @MockBean, as the bean will. . 对应于实现代码中的每个 @Autowired 字段，测试中可以用一个 @Mock 声明mock对象，并用 @InjectMocks 标示需要注入的对象。. CALLS_REAL_METHODS) But my problem is, My abstract class has so many dependencies which are Autowired. use ReflectionTestUtils. base. There is the simplest solution to use Mockito. . When this happens, it might be an indication that the class is violating the Single Responsibility Principle and you should break down that class into multiple independent classes. Mockitoとは. So the issue is @InjectMocks call default constructor before even testing a method, inside the default constructor, they have used a static class and a setter to set a field, and hence injecting mocks using @Inject is unable. And via Spring @Autowired. LambdaTest Learning Hubs compile a list of step-by-step guides to help you be proficient with different test automation frameworks i. If you are using SpringRunner. Neither SpringExtension nor MockitoExtension will inject MockBean to InjectMocks. 만약 이런 설정 없이 @Mock 등을. You are using @InjectMocks on your messageService variable. We can specify the mock objects to be injected using @Mock or @Spy annotations. 1 Enable Mockito Annotations. @Mock creates a new mock. lang. mockito:mockito-core:2. So equivalent java class for SWService would look like. Q&A for work. 在單元測試(Unit Test)的物件生成套件Mockito中，@Mock與@InjectMocks的區別如下。 @Mock的成員變數會被注入mock物件，也就是假的物件。 @InjectMocks標記的成員變數會被注入被標註@Mock的mock物件。; 在撰寫測試類別時(例如UserServiceImplTest)，如果被測試類別的某個方法(例. 38. And Inside that method write MockitoAnnotations. @InjectMocks - Instantiates testing object instance and tries to inject fields annotated with @Mock or @Spy into private fields of testing object @Mock - Creates mock instance of the field it. 2. I debugged and realized that the mocks are null. Do one of those, not both, my guess is that's where your problem lies. Mockito는 Java에서 인기있는 Mocking framework입니다. In Mockito, we need to create the class object being tested and then mock in its dependencies to fully test the behavior. @ExtendWith (MockitoExtension. class) public class aTest () { @Mock private B b; @Mock private C c; @Autowired @InjectMocks private A a; } If you want D to be Autowired dont need to do anything in your Test class. This is useful when we have external dependencies in the class we want to mock. Interestingly when running this test in maven it fails but when I try to run it in my IDE (Intellij) it is succesful. JUnitのテストの階層化と@InjectMocks. injectmocks (One. 目次. 28. You want to verify if a certain method is called. Mockito-driven test would have @RunWith(MockitoJUnitRunner. @InjectMocks：创建一个实例，并将@Mock（或@Spy）注解创建的mock注入到用该实例中。 和之前的代码相比，在使用了这两个注解之后，setup()方法也发生了变化。额外增加了以下这样一行代码。 MockitoAnnotations. Sorted by: 1. @InjectMocks. To use @MockBean you would need to annotate the class with @RunWith (SpringRunner. Share. この記事ではInjectMocksできない場合の対処法について解説します。. We can use it to create mock class fields as well as local mocks in a method. I would like to understand why in this specific situation the @InjectMocks does not know to inject the property from the abstract class. Take a look into the Javadoc of @InjectMocks. However for using @Mock you can use @RunWith (MockitoJUnitRunner. (Both will inject a Mock). Modified 6 years, 10 months ago. @Autowird 等方式完成自动注入。. 4 @Captor. 📌Please do subscribe my channel: quick difference between @Mock and @InjectMocks. JUnitのテストの階層化と@InjectMocks. This tutorial uses Spring MVC, Spring MockMVC. Using real dependencies is also possible, but in that case you need to construct SUT manually - Mockito does not support partial injections. Learn more about TeamsThe @InjectMocks annotation automatically injects mock objects annotated with @Mock through constructor injection, setter injection, or property injection. 因此对于被测试对象的创建，Mock 属性的注入应该让 @Mock 和 @InjectMocks这两个注解大显身手了。. 在单元测试中，没有. InjectMocks in Mockito already is quite complicated (and occasionally surprising for newcomers - e. Annotating them with the @Mock annotation, and. i am not sure, maybe it is not clear to mockito where to inject the mock or maybe you cannot inject mocks into a spy (just an assumption). Mockito will try to inject mocks only either by constructor injection, setter injection, or property injection in order and as described below. @RunWith (MockitoJUnitRunner. Therefore, you can create a ticket for that in Mockito, but the team would be probably. And yes constructor injection is probably the best and the correct approach to dependency injection as the author even suggest (as a reminder @InjectMocks tries first to. Something like this: public interface MyDependency { public int otherMethod (); } public class MyHandler { @AutoWired private MyDependency myDependency; public void someMethod () {. 2. You can apply the extension by adding @ExtendWith (MockitoExtension. Use @SpringBootTest or @SpringMvcTest to start a spring context together with @MockBean to create mock objects and @Autowired to get an instance of class you want to test, the mockbeans will be used for its autowired dependencies. I'm doing InjectMocks and I'm getting this error: "java. class) instead of @SpringBootTest. 比如：. You just need to mock the service call and call the controller method. If I tried to simply mock SomeClass. Alternatively, you can run your test class by enabling MockitoJUnit runner programmatically. initMocks (this) to initialize these mocks and. When running the JUnit test case with Mockito, I am getting null value returned from below manager. CALLS_REAL_METHODS); @MockBean private MamApiDao mamApiDao; @BeforeEach void setUp () { MockitoAnnotations. g. If this abstract pathname does not denote a directory, then this. ArgumentCaptor allows us to capture an argument passed to a method to inspect it. when. @Mock：创建一个Mock。. –When using @InjectMocks, it automatically tries to inject in the order: constructor, setter, field. Follow asked Nov 18, 2019 at 18:39. @Spy private SampleProperties properties; A field annotated with @Spy can be initialized explicitly at declaration point. Mockito 관련 어노테이션 @RunWith(MockitoJunitRunner. initMocks(this); abcController. use @ExtendWith (MockitoExtension. @InjectMocks works as a sort of stand-in dependency injection for the system under test: If you have a test that defines a @Mock or @Spy of the right type, Mockito will initialize any fields in your @InjectMocks instance with the contents of. And logic of a BirthDay should have it's own Test class. Your @RunWith(SpringRunner. xml: We also need to tell Maven that we’re working with Kotlin so that it compiles the source code for us. *initMocks*(this); 也就是实现了对上述mock的初始化工作。4. 1. Which makes it easier to initialize with mocks. Return something for your Mock. We can specify the mock objects to be injected using @Mock. MockBean is used to replace a bean in existing spring context, and is typically combined with Autowired to inject beans into your test. you will have to provide dependencies yourself. Setup. Injection allows you to, Enable shorthand mock and spy injections. Both @Mock and @MockBean create mock objects that can be used to define the behavior of the mocked objects. While this may work, it is a gross misuse of the API. public class OneTest { private One one; @Test public void testAddNode () { Map<String, String> nodes = Mockito. The problem is the class under test, which is annotated with @InjectMocks. initMocks (this); }. beans. Focus on writing functions such that the testing is not hindered by the. class, Mockito. class); one = Mockito. We have a simple POJO class that holds Post data with the following structure: The DBConnection class is responsible for opening and closing database connection: In. private LoaCorpPayDtlMapper loaCorpPayDtlMapper; @InjectMocks // Solo para la clase, puede ingresar la clase en tiempo de ejecución y volver a colocar el valor de Mockito para el método especificado. The @InjectMocks annotation is used to insert all dependencies into the test class. Use @InjectMocks when we need all or a few internal dependencies. I have to test a class that takes 2 objects via constructor and other 2 via @Autowired. As you see, the Car class needs the Driver object to printWelcome () message. So, for the first invocation, the method processInjection in ConstructorInjection will initialize the class annotated with @InjectMocks inside helper class FieldInitializationReport by checking that Plugins. So yes it fails silently, because Mockito is not able to confirm an object is correctly initialized or not when this object relies on fields/setters, it’s just impossible. If you wish to use the Mockito annotation @InjectMocks then I'd recommend not using any Spring-related mocking annotations at all, but rather the @Mock annotation to create a mocked version of the bean you want to inject (into the. class, that mock is not injected and that object is null in my tests. Mock + InjectMocks + MockitoExtension is far simpler setup in service test. This video explains how to use @InjectMock and @Mock Annotation and ho. This is my first junit tests using Mockito. 모의 객체(Mockito) 사용하기. The @InjectMocks annotation is used to insert all dependencies into the test class. 3 Answers. The problem is the nested mapper is always null in my unit tests (works well in the application) this is my mapper declaration : @Mapper (componentModel = "spring", uses = MappingUtils. Two ways to solve this: 1) You need to use MockitoAnnotations. 1. Your Autowired A should have correct instance of D . What you should do in this case is mock the values instead of mocking the whole container, the container here is MyClass. . tl;dr: Use @Mock when unit testing your business logic (only using JUnit and Mockito). Stubbing a Spy. It will initialize mock the @MockeBean and @bean anotted beans at the intial time of test run. Autowired; 2. This method returns a MockedStatic object for our type, which is a scoped mock object. How To Use @InjectMocks For A Dependency For Another Class To Be Mocked? 3. class in a wrong way. Usually when you are unit testing, you shouldn't initialize Spring context. openMocks(this)で作成されたリソースは、closeメソッドによって. The first one will create a mock for the class used to define the field and the second one will try to inject said. You haven't provided the instance at field declaration so I tried to construct the instance. If you want to create just a Mockito test you could use the annotation @RunWith (MockitoJUnitRunner. 4, and the powermock-api-mockito was not.