Java Spring How to mock beans which implements the same interface

Question

I've a bean which is created as follow

@Profile({"test", "dev", "int"})
@Bean
public CustomerEmailSenderImpl customerEmailSenderImpl(){
    return new CustomerEmailSenderImpl ();
}

And in a test class, I mock the class as follow:

   @ActiveProfiles(profiles = {"test"})
   .....
    @MockBean
    private CustomerEmailSenderImpl customerEmailSenderImpl;

Now. I have to create a second email class which must be used specifically when with profile "test". So I created an Interface (CustomerEmailSender) which both classes implement. And the bean creation is done as follow.

@Profile({"dev", "int"})
@Bean(name = "customerEmailSender")
public CustomerEmailSender customerEmailSenderImpl1(){
    return new CustomerEmailSenderImpl1 ();
}

@Profile({"test"})
@Bean(name = "customerEmailSender")
public CustomerEmailSender customerEmailSenderImpl2(){
    return new CustomerEmailSenderImpl2 ();
}

The Mock I changed a follow

@ActiveProfiles(profiles = {"test"})
...
@MockBean
private CustomerEmailSender customerEmailSender;

The application starts without errors. But the test doesn't mock the bean CustomerEmailSenderImpl2. The bean is always instantiated, and the real code is executed. Even changing from Interface to Class-name in the test class didn't help:

@MockBean
private CustomerEmailSenderImpl2 customerEmailSenderImpl2;

What is needed to have the bean CustomerEmailSenderImpl2 mocked ?

this might be helpful https://stackoverflow.com/questions/10534053/autowiring-two-beans-implementing-same-interface-how-to-set-default-bean-to-au — Stultuske, Jun 18 '21 at 11:25
in that case, your title has nothing to do with your question. Do you know how to use a mocking framework? personally I mostly use Mockito — Stultuske, Jun 18 '21 at 11:32
I don't see how you expect a mock to be returned if you `return new CustomerEmailSenderImpl2 ()` in the config. — daniu, Jun 18 '21 at 11:32
When the Mock works, Spring doesn't instantiate the bean , and thus doesn't use the code in the config class. — user2023141, Jun 18 '21 at 11:35
We're going to need an [mcve]. So many possibilities and combinations of annotations to both spring and junit. — daniu, Jun 18 '21 at 11:39
do you have `@RunWith(SpringRunner.class)` before your test? — Uladzislau Kaminski, Jun 18 '21 at 12:24

score 0 · Accepted Answer · answered Jun 18 '21 at 12:19

The solution is to use @Qualifier, and then to use the qualifier name as variable name in the test class.

@Profile({"test"})
@Bean(name = "customerEmailSender")
@Qualifier(value="customerEmailSenderImpl2")
public CustomerEmailSender customerEmailSenderImpl2(){
    return new CustomerEmailSenderImpl2 ();
}



@MockBean
private CustomerEmailSender customerEmailSenderImpl2;

Java Spring How to mock beans which implements the same interface

1 Answers1