Beans are not Autowired during tests (java.lang.NullPointerException) - java

my application normally works fine, but when I run tests, or build application by maven, application is shutting down due tests with errors java.lang.NullPointerException. I debugged it and find out my that my beans in service layer are not Autowired and they are null.
Here is my class with tests:
public class CompanyServiceSimpleTest {
private CompanyService companyService;
#Before
public void setUp() {
companyService = new CompanyServiceImpl();
}
// Here is sample test
#Test
public void testNumberOfCompanies() {
Assert.assertEquals(2, companyService.findAll().size());
}
}
companyService is initialized, but beans in it not. Here is CompanyServiceImpl:
#Service
public class CompanyServiceImpl implements CompanyService {
#Autowired
private CompanyRepository companyRepository; // is null
#Autowired
private NotificationService notificationService; // is null
#Override
public List<CompanyDto> findAll() {
List<CompanyEntity> entities = companyRepository.find(0, Integer.MAX_VALUE);
return entities.stream().map(Translations.COMPANY_DOMAIN_TO_DTO).collect(Collectors.toList());
}
// ... some other functions
}
So when is called companyRepository.find() applications crashes. Here is repository class:
#Repository
#Profile("inMemory")
public class CompanyInMemoryRepository implements CompanyRepository {
private final List<CompanyEntity> DATA = new ArrayList<>();
private AtomicLong idGenerator = new AtomicLong(3);
#Override
public List<CompanyEntity> find(int offset, int limit) {
return DATA.subList(offset, Math.min(offset+limit, DATA.size()));
}
// ... some others functions
}
I have set up profile for that service but I had that VM options in Idea:
-Dspring.profiles.active=develpment,inMemory
So it should works.

To make autowiring work it has to be a Spring integration test. You have to anotate your test class with:
#RunWith(SpringJUnit4ClassRunner.class) and #ContextConfiguration(classes = {MyApplicationConfig.class})
If it is a Spring Boot app e.g.:
#RunWith(SpringJUnit4ClassRunner.class) and #SpringBootTest(classes = {MyApp.class, MyApplicationConfig.class}, webEnvironment = SpringBootTest.WebEnvironment.DEFINED_PORT)
More on this topic: http://www.baeldung.com/integration-testing-in-spring and http://www.baeldung.com/spring-boot-testing

You are not configuring Spring in your TestClasses, so it's impossible to inject anything...
Try configurin your class with
#RunWith(SpringJUnit4ClassRunner.class)
#ContextConfiguration(locations = { "path to your config xml" })
A little example:
#RunWith(SpringJUnit4ClassRunner.class)
#ContextConfiguration(locations = {"classpath:config/applicationContext.xml"})
public class MyTest {
#Autowired
private MyClass myInjectedClass;
#Test
public void someTest() {
assertNotNull(myInjectedClass);
}
}

Related

Autowired constructor not instantiating dependencies properly in Springboot

I have an integration which instantiates a service and that service has an Autowired dependency on a bean I'm trying to mock.
The problem is the service is getting instantiated before the autowired bean is and causing NPE. How can I ensure DependencyINeed is initialized before the MyClass in the example below?
Service
#Service
public class MyClass {
#Autowired private DependencyINeed dependency;
#Autowired
public MyClass(
#Value("${thing1}") int t1,
#Value("${thing2}") String t2) {
}
Method call yielding NPE
public class MyClass {
....
public void randomFunction() {
dependency.methodCall() <-- NPE
}
}
Test
#ContextConfiguration(classes = TestConfiguration.class)
#Import({TestConfiguration.class})
#SpringBootTest(
classes = {TestConfiguration.class, DependencyINeed.class, MyClass.class})
public class MyCoolIntegrationTest {
#Autowired private DependencyINeed dependency;
#Autowired private MyClass client;
Test Configuration
#TestConfiguration
public class MyTestConfiguration {
#MockBean private DependencyINeed dep;
#Bean
public DependencyINeed initDep() {
....
return dep;
}
}
Try to delete yout test config, and make yout Test class look like this:
#ContextConfiguration(classes = TestConfiguration.class)
#Import({TestConfiguration.class})
#SpringBootTest(
classes = {TestConfiguration.class, DependencyINeed.class, MyClass.class})
public class MyCoolIntegrationTest {
#MockBean private DependencyINeed dependency;
#Autowired private MyClass client;
#BeforeEach
public void beforeEach() {
Mockito.when(dependency.SOMEHING()).thenReturn(YOUR STUFF);
}
}

#Repository instance is null when invoking a method using a #Service instance from a unit test

My goal is to use an in-memory database for these unit tests, and those dependancies are listed as:
implementation("org.springframework.boot:spring-boot-starter-data-jpa")
runtimeOnly("com.h2database:h2")
So that the repository instance actually interacts with a DB, and I dont just mock return values.
The problem is that when I run my unit test, the repository instance inside the service instance is null.
Why is that? Am I missing some annotation on the unit test class to initialise the repository instance?
This is the console output when running my unit test:
null
java.lang.NullPointerException
at com.my.MyService.findAll(MyService.java:20)
at com.my.MyTest.testMy(MyTest.java:23)
My unit test class:
public class MyTest {
#MockBean
MyRepository myRepository;
#Test
void testMy() {
MyService myService = new MyService();
int size = myService.findAll().size();
Assertions.assertEquals(0, size);
}
}
My service class:
#Service
public class MyService {
#Autowired
MyRepository myRepository;
public List<MyEntity> findAll() {
System.out.println(myRepository); // null
return (List<MyEntity>) myRepository.findAll(); // throws NullPointerException
}
#Transactional
public MyEntity create(MyEntity myEntity) {
myRepository.save(myEntity);
return myEntity;
}
}
My repository class:
#Repository
public interface MyRepository extends CrudRepository<MyEntity, Long> {
}
My entity class:
#Entity
public class MyEntity {
#Id
#GeneratedValue
public Long id;
}
Why is that? Am I missing some annotation on the unit test class to initialise the repository instance?
Basically yes :)
You need to initialise a Spring Context by Annotating your Testclass with #SpringBootTest
The other Problem you have is that you create your MyService Object manually.
By doing so SpringBoot has no chance to inject any Bean for you. You can fix this by simply injecting your MyService in your Testclass. Your Code should look something like this:
#SpringBootTest
public class MyTest {
#Autowired
private MyService myService;
#Test
void testMy() {
int size = myService.findAll().size();
assertEquals(0, size);
}
}
To use #MockBean annotation, you have to use SpringRunner to run the test. Use #RunWith Annotation on top of your test class and pass SpringRunner.class.
#RunWith(SpringRunner.class)
public class MyTest {
#MockBean
MyRepository myRepository;
#Test
void testMy() {
MyService myService = new MyService();
int size = myService.findAll().size();
Assertions.assertEquals(0, size);
}
}
The problem here is your service implementation. Using #Autowired to inject the dependency will work when you run the whole app, but it do not allow you to inject a custom dependency when you'll need it, and a good example of this is testing.
Change your service implementation to:
#Service
public class MyService {
private MyRepository myRepository;
public MyService(MyRepository myRepository){
this.myRepository = myRepository;
}
public List<MyEntity> findAll() {
System.out.println(myRepository); // null
return (List<MyEntity>) myRepository.findAll(); // throws NullPointerException
}
#Transactional
public MyEntity create(MyEntity myEntity) {
myRepository.save(myEntity);
return myEntity;
}
}
This constructor will be called by spring. Then change your test to:
public class MyTest {
#Mock
MyRepository myRepository;
#Test
void testMy() {
MyService myService = new MyService(myRepository);
int size = myService.findAll().size();
Assertions.assertEquals(0, size);
}
}
Note I have replaced #MockBean to #Mock as the previous annotation is for injecting a mock bean into the spring context, which is not needed if you're doing unit testing. If you want to boot spring context (which I would not recommend you) you need to configure your test class with #SpringBootTest or some of the other available alternatives. That will convert your test into an integration test.
PD: This test will not work if you don't provide a mock to myRepository.findAll(). Mockito default behaviour is to return null, but you're expecting it to return 0, so you'll need to do something like given(myRepository.findAll()).willReturn(0).
I believe you wish to write an integration test. Here you could remove the MockBean annotation and simply autowire your repository. Also, run with The SpringRunner class.
#RunWith(SpringRunner.class)
public class MyTest {
#Autowired
MyRepository myRepository;
#Autowired
MyService myService
#Test
void testMy() {
int size = myService.findAll().size();
Assertions.assertEquals(0, size);
}
}
This should work

Overriding spring #Configuration in an integration test

I have a spring boot configuration class like this:
#Configuration
public class ClockConfiguration {
#Bean
public Clock getSystemClock() {
return Clock.systemUTC();
}
}
and I have some integration tests like this:
#SpringBootTest(classes = MyApplication.class, webEnvironment = WebEnvironment.RANDOM_PORT)
public abstract class AbstractIntegrationTest {
}
and tests like this:
public class MiscTests extends AbstractIntegrationTest{
#Test
public void CreateSomethingThatOnlyWorksInThe Morning_ExpectCorrectResponse() {
}
I want to be able to offset the clock bean to run some tests at different times on the day. How do I do this?
NOTE: I see several stack overflow answers similar to this, but I can't get them to work.
Based on other responses, it appears the solution should be something like:
#SpringBootTest(classes = MyApplication.class, webEnvironment = WebEnvironment.RANDOM_PORT)
public abstract class AbstractIntegrationTest {
#Configuration
class MyTestConfiguration {
#Bean
public Clock getSystemClock() {
Clock realClock = Clock.systemDefaultZone();
return Clock.offset(realClock, Duration.ofHours(9));
}
}
}
But nothing happens there. Do I need to #Import something? do I need to #Autowired something?
Thanks!
As you are using Spring Boot you can take advantage of the #MockBean annotation:
#SpringBootTest(classes = MyApplication.class, webEnvironment = WebEnvironment.RANDOM_PORT)
public abstract class AbstractIntegrationTest {
#MockBean
private Clock clockMock;
}
Then you can stub public methods of that bean an each of the tests accordingly and uniquely:
#Test
public void CreateSomethingThatOnlyWorksInThe Morning_ExpectCorrectResponse() {
when(clockMock.getTime()).thenReturn(..);
}
As per javadoc of #MockBean:
Any existing single bean of the same type defined in the context will
be replaced by the mock.
it is the #TestConfiguration annotation that you need https://docs.spring.io/spring-boot/docs/current/api/org/springframework/boot/test/context/TestConfiguration.html
#RunWith(SpringRunner.class)
public class ClockServiceImplIntegrationTest {
#TestConfiguration
static class TestOverridingClockServiceConfiguration {
#Bean
public ClockService clockService() {
return new ClockServiceImpl();
}
}
#Autowired
private ClockService clockService;
#MockBean
private ClockRepository clockRepository;
// write test cases here
}
In the case you have existing configuration you c

Mock embedded objects in integration test

Trying to write an integration test for a Spring application. Say i've got a class A which contains a class B object. Class B contains a class C object and I need to mock an object within this class for the integration test - any idea how i go about doing that without passing every object through as a parameter in the constructor?
e.g.
#Service
Class A {
#Autowired
private B b;
public void testA() {
B.testB();
}
}
#Service
Class B {
#Autowired
private C c;
public void testB() {
c.testC();
}
}
#Service
Class C {
//External class pulled in from dependency library
#Autowired
private RestTemplate restTemplate;
public void testC() {
restTemplate.doSomethingInOutsideWorld();
}
}
Integration test:
#RunWith(JUnitParamsRunner.class)
#SpringBootTest
public class MyIt {
#ClassRule
public static final SpringClassRule SPRING_CLASS_RULE = new SpringClassRule();
#Rule
public final SpringMethodRule springMethodRule = new SpringMethodRule();
#Mock
private RestTemplate restTemplate;
#Autowired
private A a;
#InjectMocks
private C c;
#Before
public void setup() {
initMocks(this);
}
#Test
public void test1() throws IOException {
a.testA()
}
}
Doesn't mock the RestTemplate object, it tries to hit the outside world. Any advice on how to resolve this?
Achieve this by using SpringRunner and #MockBean
#RunWith(SpringRunner.class) is used to provide a bridge between Spring Boot test features and JUnit. Whenever we are using any Spring Boot testing features in out JUnit tests, this annotation will be required.
The #SpringBootTest annotation can be used when we need to bootstrap the entire container. The annotation works by creating the ApplicationContext that will be utilized in our tests.
Annotation that can be used to add mocks to a Spring ApplicationContext. Can be used as a class level annotation or on fields in either #Configuration classes, or test classes that are #RunWith the SpringRunner.
#RunWith(SpringRunner.class)
#SpringBootTest
public class MyIt {
#MockBean
private RestTemplate restTemplate;
#Autowired
private A a;
#Before
public void setup() {
initMocks(this);
}
#Test
public void test1() throws IOException {
given(this.restTemplate.doSomethingInOutsideWorld()).willReturn(custom object);
a.testA()
}
}

Mock object method call using Spring Boot and Mockito

I am trying to write a test for this Java SpringBoot's class:
https://github.com/callistaenterprise/blog-microservices/blob/master/microservices/composite/product-composite-service/src/main/java/se/callista/microservices/composite/product/service/ProductCompositeIntegration.java
Specifically, I am trying to "mock" this method call:
URI uri = util.getServiceUrl("product");
I figured out I should "mock" the ServiceUtils object in order to do this. I tried this using the #Mock and #InjectMocks annotations:
#RunWith(SpringJUnit4ClassRunner.class)
#SpringApplicationConfiguration(classes = ProductCompositeServiceApplication.class)
public class ProductCompositeIntegrationTest {
#InjectMocks
#Autowired
private ProductCompositeIntegration productIntegration;
#Autowired
private RestTemplate restTemplate;
#Mock
private ServiceUtils util;
private MockRestServiceServer mockServer;
#Before
public void setUp() {
MockitoAnnotations.initMocks(this);
mockServer = MockRestServiceServer.createServer(restTemplate);
}
#Test
public void myTest() {
Mockito.when(util.getServiceUrl("product")).thenReturn(URI.create("http://localhost:8080/test"));
ResponseEntity<Iterable<Product>> products = productIntegration.getAllProducts();
}
}
But this way it still calls the original ServiceUtils object, and not the "mocked" one. Also tried without the #Autowired annotation at the ProductCompositeIntegration, but this results in a NullPointerException.
What am I doing wrong?
My main class looks like this:
#SpringBootApplication
#EnableCircuitBreaker
#EnableDiscoveryClient
public class ProductCompositeServiceApplication {
public static void main(String[] args) {
SpringApplication.run(ProductCompositeServiceApplication.class, args);
}
}
The ServiceUtils object that I am trying to mock is specified in a class, annotated with Spring's #Component annotation to inject it into the other classes using #Autowired.
After a lot of trial and error I managed to solve this problem.
I dropped the
#RunWith(SpringJUnit4ClassRunner.class)
#SpringApplicationConfiguration(classes = ProductCompositeServiceApplication.class)
annotations aboved the test class.
I marked the class that I was testing with #InjectMocks and the dependencies with #Mock:
public class ProductCompositeIntegrationTest {
#InjectMocks
private ProductCompositeIntegration productIntegration;
#Mock
private ServiceUtils util;
private MockRestServiceServer mockServer;
private RestTemplate restTemplate = new RestTemplate();
#Before
public void init() {
MockitoAnnotations.initMocks(this);
mockServer = MockRestServiceServer.createServer(restTemplate);
productIntegration.setRestTemplate(restTemplate);
}
#Test
public void someTests() {
when(util.getServiceUrl("product")).thenReturn(URI.create("http://localhost:8080/test"));
//Test code...
}
}
I'm not sure if this is the best approach ("the Spring way"), but this worked for me.
This article made it all clear to me: http://rdafbn.blogspot.be/2014/01/testing-spring-components-with-mockito.html
You have to write a FactoryBean like
public class MockitoFactoryBean<T> implements FactoryBean<T> {
private Class<T> classToBeMocked;
public MockitoFactoryBean(Class<T> classToBeMocked) {
this.classToBeMocked = classToBeMocked;
}
#Override
public T getObject() throws Exception {
return Mockito.mock(classToBeMocked);
}
#Override
public Class<?> getObjectType() {
return classToBeMocked;
}
#Override
public boolean isSingleton() {
return true;
}
}
In your test-context.xml you have to add the following lines.
<bean id="serviceUtilMock" class="MockitoFactoryBean">
<constructor-arg value="your.package.ServiceUtil" />
</bean>
If you don't use XML configuration, then you have to add the equivalent to above in your Java configuration.

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