unable to mock RestTemplate response - spring-boot

Question

I wanted to mock the RestTemplate's result, but with my code below, it always went to do the Http. Can someone please advise? I think I have parts that I did wrongly, please help.
UserServiceTest.java
#RunWith(SpringJUnit4ClassRunner.class)
public class UserServiceTest(){
#InjectMock
#Autowired
UserService userservice;
#Mock
RestTemplate restTemplate;
#Value(${aa.bb.cc})
private String getfromapplicationpropertiesVal;
#Test
public void test1(){
HttpHeaders headers = new HttpHeaders();
headers.setContentType(MediaType.APPLICATION_JSON);
String jsonBody = null;
HttpEntity<String> entity = new HttpEntity<>(jsonBody, headers);
String textContent = "result from junit";
ResponseEntity<String> response = new ResponseEntity<>(textContent, HttpStatus.OK);
String url = "http://localhost:8080/test/test.txt";
doReturn(response).when(restTemplate).exchange(
eq(url),
any(HttpMethod.class),
any(HttpEntity.class),
any(Class.class)
);
userservice.test();
}
}
UserService.java
#Service
public class UserService{
#Autowired
HttpHelperService httpHelperService;
public void test(){
String url = "http://localhost:8080/test/test.txt";
String response = httpHelperService.cal(url, HttpMethod.GET);
System.out.println(response);
}
}
HttpHelperService.java
#Service
public class HttpHelperService{
#Autowired
private RestTemplate restTemplate;
public String cal(String url, HttpMethod httpMethod){
HttpHeaders headers = new HttpHeaders();
headers.setContentType(MediaType.APPLICATION_JSON);
String jsonBody = null;
HttpEntity<String> entity = new HttpEntity<>(jsonBody, headers);
String response = restTemplate.exchange(url, httpMethod, entity, String.class); //This part kept calling http when run the #Test
}
}
RestTemplateConfig
#Configuration
public class RestTemplateConfig{
#Bean
public RestTemplate restTemplate(){
return new RestTemplate();
}
}

Answer 1

Recommendation in these type of scenario is to use MockRestServiceServer & not mocking restTemplate.
You might do something like this:
#Mock
RestTemplate restTemplate;
#Autowired
MockRestServiceServer mockServer;
#BeforeEach
public void init(){
mockServer = MockRestServiceServer.createServer(restTemplate); //initialization
}
And then invoke mock for your service something like :
mockServer.expect(requestTo(url))
.andExpect(method(HttpMethod.GET))
.andRespond(withSuccess("successOperation"));
-Alternatively, you can just mock your test() method:
when(mockedHttpHelperService).cal(anyString(),HttpMethod.GET).thenReturn("success");