如何模拟 rest 模板和响应实体

Question

I m new to JUnit and Mockito concepts and trying to figure out how it's done in a rest template call. Consider the below rough implementation,

Class TheWrapper{

  @Autowired
  RestTemplate template;

}

Class Abc extends TheWrapper{

  boolean validation(){

      // .....
     //carries out different validation operations
     //  .....

     try{
       
        ResponseEntity<Object> response= template.postForEntity("localhost:8080...",obj,Object.class);

        if(response.getStatusCodeValue()==200) // Problem: throwing MyCustomException here, 
                                               // when test is runned
          return true;
        else
          return false;
     
     }catch(Exception e){
        throws new MyCustomException(...);
     }

}

Now I need to write unit testing in such a way that, I have to mock the rest template call and
check whether the status code is 200 or not.

Class Testing{

  @InjectMock
  Abc obj;

  @Mock
  RestTemplate template;

  @BeforeEach
  void setup(){
    obj=new Abc();
    MockitoAnnotations.initMocks(this);
   }

  @Test
  void testingIt(){
    
   ResponseEntity<Object> response=new ResponseEntity<Object>(HttpStatus.OK);
  
   when(template.postForEntity("local...",any(),any())).then(response)

   Assertion.assertEquals(obj.validation(),true);

  }
}

If this is not the way to implement, please do correct me.

Answer 1

Rest template overloaded method postForEntity multiple times. Make sure you define the correct one. Also, you can use anyString() instead of 'local...'.

template.postForEntity(anyString(),any(),any())

Answer 2

You can use a separate service to maintain all mock response. Wiremock is one such useful application you can use. You can have all possible combination of HTTP request/response, and status code as well. Using wiremock you can also create separate files of request-response mapping, which can be useful in avoiding hardcoding. http://wiremock.org/docs/getting-started/