Mockito返回空

Question

我有下面的A类实现，使用spring引导。A是对restTemplate进行GET/POST/PUT RestAPI调用的抽象。测试是用Mockito编写的。

Class A {

@Bean
RestTemplate restTemplate;

public class A(RestTemplate restTemplate){
    this.restTemplate = restTemplate;
}

public ResponseEntity perform(String endPoint, String requestBody, String auth, HttpMethod httpMethod){
    ...code to create parameters to pass to the exchange method
    ResponseEntity responseEntity = restTemplate.exchange(url, httpMethod, requestEntity, String.class)
    return responseEntity;
 }

}

用Mockito：单元测试：

class ATest{
    A a;

    @Spy
    RestTemplate restTemplate;

    @Before
    public void setUp() {
        a = Mockito.spy(new A(restTemplate));
    }
    
      @Test
    public void testHttpUtil(){
        ResponseEntity responseEntity = new ResponseEntity(HttpStatus.OK);
        HttpHeaders headers = new HttpHeaders();
        headers.set("Authorization" , "testAuth");
        HttpEntity<String> requestEntity = new HttpEntity<String>("testPayload", headers);
        Mockito.doReturn(responseEntity).when(restTemplate).exchange(Mockito.any(),Mockito.eq(HttpMethod.POST), Mockito.any(HttpEntity.class), Mockito.eq(String.class));
        ResponseEntity responseEntity1 = a.perform("https://example.com/v1/testapi", "testpayload", "testauthinfo", MediaType.APPLICATION_JSON_VALUE, HttpMethod.POST );
        Assert.assertNotNull(responseEntity1);
        Mockito.verify(restTemplate, Mockito.atMost(1)).exchange(Mockito.any(),Mockito.eq(HttpMethod.POST), Mockito.any(HttpEntity.class), Mockito.eq(String.class));

    }
}

这个实现背后的想法是，在调用A的执行方法时，模拟restTemplate的exchange方法，并返回一个响应。现在，在A的执行方法上返回null。看来我做错什么了。有人能帮我吗？

为了规避这个问题，我嘲笑了RestTemplate并使用了

Mockito.verify(restTemplate, Mockito.atMost(1)).exchange(Mockito.any(),Mockito.eq(HttpMethod.POST), Mockito.any(HttpEntity.class), Mockito.eq(String.class));来查找调用restTemplate.exchange方法的次数。测试已经通过了。但仍然想知道问题中发布的实现有什么问题

Answer 1

更新:在实例化restTemplate时，测试通过了。对测试代码进行以下更改。

@Spy
RestTemplate restTemplate = new RestTemplate();