Ambiguous Method Call Mocking RestTemplate.exchange()

Question

Can\'t figure out the correct way to use matchers to identify which overload of the exchange method I am targetting. The call I am making:

restTemplate.exchange(ur

Answer 1

Most likely you are using the when().then() pattern.

Try the doReturn().when() approach with your matchers.

Just make sure you use matchers even for the params that you expect directly (use eq() for this).

Here is the issue and fix on project issue tracker.

Answer 2

I am not sure whether I misunderstood your question or the issue mentioned by @MarciejKowalski, but when running the test from the issue or what I suppose is similar to your example against mockito-core-2.23.4 / JDK 1.8.0_151 it works just fine.

[I used JUnit 4 for your example instead of JUnit 5]

import static org.mockito.ArgumentMatchers.any;

import org.junit.Assert;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.mockito.Mockito;
import org.mockito.junit.MockitoJUnitRunner;
import org.springframework.core.ParameterizedTypeReference;
import org.springframework.http.HttpEntity;
import org.springframework.http.HttpMethod;
import org.springframework.http.ResponseEntity;
import org.springframework.web.client.RestTemplate;

@RunWith(MockitoJUnitRunner.class)
public class MockitoTest {

    @Test
    public void test() {

        RestTemplate api = Mockito.mock(RestTemplate.class);
        ResponseEntity<?> response1 = Mockito.mock(ResponseEntity.class);
        ResponseEntity<?> response2 = Mockito.mock(ResponseEntity.class);

        Mockito.when(api.exchange(any(String.class), any(HttpMethod.class), any(HttpEntity.class), any(Class.class))).thenReturn(response1);
        Mockito.when(api.exchange(any(String.class), any(HttpMethod.class), any(HttpEntity.class), any(ParameterizedTypeReference.class))).thenReturn(response2);

        ParameterizedTypeReference mock = Mockito.mock(ParameterizedTypeReference.class);

        Assert.assertEquals(response1, api.exchange("", HttpMethod.GET, new HttpEntity(""), String.class));
        Assert.assertEquals(response2, api.exchange("", HttpMethod.GET, new HttpEntity(""), mock));
    }
}