Given this question on Stackoverflow I wanted to check whether there is a difference between this style of Bean definition (variant 1):
@Configuration
public class BeanConfiguration {
@Bean
public FirstClass firstClass() {
return new FirstClass();
}
@Bean
public SecondClass secondClass() {
return new SecondClass(firstClass());
}
public static class FirstClass {
public String get() {
return "FirstClass";
}
}
public class SecondClass {
private final FirstClass firstClass;
public SecondClass(FirstClass firstClass) {
this.firstClass = firstClass;
}
public String get() {
return firstClass.get();
}
}
}and this style (variant 2):
@Configuration
public class BeanConfiguration {
@Bean
public FirstClass firstClass() {
return new FirstClass();
}
@Bean
public SecondClass secondClass(FirstClass firstClass) {
return new SecondClass(firstClass);
}
public static class FirstClass {
public String get() {
return "FirstClass";
}
}
public class SecondClass {
private final FirstClass firstClass;
public SecondClass(FirstClass firstClass) {
this.firstClass = firstClass;
}
public String get() {
return firstClass.get();
}
}
}Given the documentation for mocking beans in the Spring Docs one could assume that mocking does not properly work with variant 1, but the following test works with both variants:
@RunWith(SpringRunner.class)
@SpringBootTest(classes = BeanConfiguration.class)
public class BeanInjectionTest {
@MockBean
private BeanConfiguration.FirstClass firstClass;
@Autowired
private BeanConfiguration.SecondClass secondClass;
@Test
public void testInjectionWithMockedDependency() {
given(this.firstClass.get()).willReturn("mock");
assertThat(secondClass.get(), is("mock"));
}
}