java - Testing @Postconstruct with Mockito

Java - Testing @Postconstruct with Mockito

To test a method annotated with @PostConstruct using Mockito, you can use the MockitoJUnitRunner or the MockitoAnnotations class to initialize mocks before the @PostConstruct method is called. Here's an example using MockitoAnnotations:

Let's say you have a class with a method annotated with @PostConstruct:

import javax.annotation.PostConstruct; public class MyClass { private SomeDependency someDependency; @PostConstruct public void init() { // Do something during initialization someDependency.initialize(); } // Other methods... public void setSomeDependency(SomeDependency someDependency) { this.someDependency = someDependency; } }

And you want to test the init method:

import org.junit.Before; import org.junit.Test; import org.mockito.InjectMocks; import org.mockito.Mock; import org.mockito.MockitoAnnotations; import static org.mockito.Mockito.verify; public class MyClassTest { @Mock private SomeDependency someDependency; @InjectMocks private MyClass myClass; @Before public void setUp() { // Initialize mocks MockitoAnnotations.initMocks(this); } @Test public void testInit() { // Call the init method myClass.init(); // Verify that someDependency.initialize() is called verify(someDependency).initialize(); } }

In this example:

  • We use @Mock to mock the SomeDependency class.
  • We use @InjectMocks to inject the mock into the MyClass instance.
  • In the setUp method, we initialize the mocks using MockitoAnnotations.initMocks(this).
  • In the testInit method, we call myClass.init() and then verify that the someDependency.initialize() method is called.

Note: Make sure you have the Mockito library in your project dependencies. If you are using a testing framework like JUnit, you can include the Mockito JUnit runner (MockitoJUnitRunner) instead of using MockitoAnnotations if your test class doesn't extend another class.

import org.junit.runner.RunWith; import org.mockito.junit.MockitoJUnitRunner; @RunWith(MockitoJUnitRunner.class) public class MyClassTest { // ... }

Choose the approach that fits your project's structure and testing preferences.

Examples

  1. "Java Mockito test @PostConstruct method execution"

    • Code:
      public class MyClass { @PostConstruct public void init() { // Initialization logic } } 
      @Test public void testPostConstructMethodExecution() { MyClass myClass = Mockito.spy(new MyClass()); Mockito.verify(myClass).init(); }
    • Description: Uses Mockito.spy to create a partial mock of the class and verifies that the @PostConstruct method (init in this case) is executed.

  2. "Java Mockito mock dependencies in @PostConstruct"

    • Code:
      public class MyClass { @Autowired private SomeDependency someDependency; @PostConstruct public void init() { // Use someDependency during initialization } } 
      @Test public void testPostConstructWithMockedDependency() { MyClass myClass = Mockito.spy(new MyClass()); SomeDependency mockedDependency = Mockito.mock(SomeDependency.class); Mockito.when(myClass.getSomeDependency()).thenReturn(mockedDependency); myClass.init(); // Verify interactions with mockedDependency Mockito.verify(mockedDependency).someMethod(); }
    • Description: Demonstrates mocking a dependency injected with @Autowired in the @PostConstruct method and verifies interactions.

  3. "Java Mockito test @PostConstruct with constructor injection"

    • Code:
      public class MyClass { private SomeDependency someDependency; @Autowired public MyClass(SomeDependency someDependency) { this.someDependency = someDependency; } @PostConstruct public void init() { // Use someDependency during initialization } } 
      @Test public void testPostConstructWithConstructorInjection() { SomeDependency mockedDependency = Mockito.mock(SomeDependency.class); MyClass myClass = new MyClass(mockedDependency); // @PostConstruct should be called during the object creation Mockito.verify(mockedDependency).someMethod(); }
    • Description: Tests the @PostConstruct method with constructor injection by creating an instance of the class and verifying interactions with the dependency.

  4. "Java Mockito test @PostConstruct with field injection"

    • Code:
      public class MyClass { @Autowired private SomeDependency someDependency; @PostConstruct public void init() { // Use someDependency during initialization } } 
      @Test public void testPostConstructWithFieldInjection() { SomeDependency mockedDependency = Mockito.mock(SomeDependency.class); MyClass myClass = new MyClass(); ReflectionTestUtils.setField(myClass, "someDependency", mockedDependency); myClass.init(); // Verify interactions with mockedDependency Mockito.verify(mockedDependency).someMethod(); }
    • Description: Tests the @PostConstruct method with field injection by setting the field using ReflectionTestUtils and verifying interactions with the dependency.

  5. "Java Mockito test multiple @PostConstruct methods"

    • Code:
      public class MyClass { @PostConstruct public void init1() { // Initialization logic 1 } @PostConstruct public void init2() { // Initialization logic 2 } } 
      @Test public void testMultiplePostConstructMethods() { MyClass myClass = Mockito.spy(new MyClass()); Mockito.verify(myClass).init1(); Mockito.verify(myClass).init2(); }
    • Description: Verifies the execution of multiple @PostConstruct methods using Mockito.spy and verify for each method.

  6. "Java Mockito test @PostConstruct with external service call"

    • Code:
      public class MyClass { @Autowired private ExternalService externalService; @PostConstruct public void init() { externalService.initialize(); } } 
      @Test public void testPostConstructWithExternalServiceCall() { MyClass myClass = Mockito.spy(new MyClass()); ExternalService mockedService = Mockito.mock(ExternalService.class); Mockito.when(myClass.getExternalService()).thenReturn(mockedService); myClass.init(); // Verify interactions with mockedService Mockito.verify(mockedService).initialize(); }
    • Description: Tests the @PostConstruct method that calls an external service by mocking the service and verifying the interaction.

  7. "Java Mockito test @PostConstruct with exception handling"

    • Code:
      public class MyClass { @PostConstruct public void init() { try { // Initialization logic } catch (Exception e) { // Exception handling } } } 
      @Test public void testPostConstructWithExceptionHandling() { MyClass myClass = Mockito.spy(new MyClass()); // Stubbing the method to throw an exception Mockito.doThrow(new RuntimeException("Simulated exception")).when(myClass).init(); // Verifying that the exception is handled myClass.init(); // Add assertions or verifications as needed }
    • Description: Tests the @PostConstruct method that includes exception handling by stubbing the method to throw an exception and verifying the expected behavior.

  8. "Java Mockito test @PostConstruct method with private method call"

    • Code:
      public class MyClass { @PostConstruct public void init() { performPrivateInitialization(); } private void performPrivateInitialization() { // Private initialization logic } } 
      @Test public void testPostConstructWithPrivateMethodCall() throws Exception { MyClass myClass = Mockito.spy(new MyClass()); // Invoking the private method using reflection Method privateMethod = MyClass.class.getDeclaredMethod("performPrivateInitialization"); privateMethod.setAccessible(true); privateMethod.invoke(myClass); // Verifying the interactions or assertions as needed }
    • Description: Tests the @PostConstruct method that calls a private method by using reflection to invoke the private method and verify interactions or assertions.

  9. "Java Mockito test @PostConstruct with mocked environment properties"

    • Code:
      public class MyClass { @Autowired private Environment environment; @Value("${some.property}") private String someProperty; @PostConstruct public void init() { someProperty = environment.getProperty("some.property"); } } 
      @Test public void testPostConstructWithMockedEnvironmentProperties() { MyClass myClass = Mockito.spy(new MyClass()); Environment mockedEnvironment = Mockito.mock(Environment.class); Mockito.when(myClass.getEnvironment()).thenReturn(mockedEnvironment); Mockito.when(mockedEnvironment.getProperty("some.property")).thenReturn("mockedValue"); myClass.init(); // Verify that the property is set correctly Assert.assertEquals("mockedValue", myClass.getSomeProperty()); }
    • Description: Tests the @PostConstruct method that retrieves a property from the environment by mocking the environment and verifying the expected behavior.

  10. "Java Mockito test @PostConstruct method with mocked bean initialization"

    • Code:
      public class MyClass { @Autowired private SomeBean someBean; @PostConstruct public void init() { someBean.initialize(); } } 
      @Test public void testPostConstructWithMockedBeanInitialization() { MyClass myClass = Mockito.spy(new MyClass()); SomeBean mockedBean = Mockito.mock(SomeBean.class); Mockito.when(myClass.getSomeBean()).thenReturn(mockedBean); myClass.init(); // Verify interactions with mockedBean Mockito.verify(mockedBean).initialize(); }
    • Description: Tests the @PostConstruct method that initializes a bean by mocking the bean and verifying the interactions.

More Tags

fbsdk ssh-keys static-content process-management html-renderer overscroll bar-chart android-alertdialog directory-structure rdd

More Programming Questions

More Financial Calculators

More Statistics Calculators

More Mixtures and solutions Calculators

More Biochemistry Calculators