使用MockRestServiceServer时，无法精确测试服务调用的数量

我正在为服务调用编写一些重试逻辑，并尝试在单元测试中测试Rest模板是否尝试命中服务一定次数。我使用以下代码来执行测试

MockRestServiceServer mockServer = MockRestServiceServer.bindTo(restTemplate).build();
mockServer.expect(ExpectedCount.times(5), method(HttpMethod.GET))
  .andRespond(withServerError());

service.call();

我将重试逻辑设置为仅进行两次尝试。上面的测试代码要求它发生五次，但测试总是通过。事实上，我可以让这个测试失败的唯一方法是将预期计数设置为1（任何小于实际调用次数的值）。当我使用

ExpectedCount.min

或

ExpectedCount.between

时，也会出现同样的问题，因为只有当实际调用超过预期时，测试才会失败

---

我需要能够测试服务调用的确切数量，最好不使用Mockito。

您可以使用所需的逻辑创建自己的ResponseCreator。例如：

class DelegateResponseCreator implements ResponseCreator {
    private final ResponseCreator[] delegates;
    private int toExecute = 0;

    public DelegateResponseCreator(final ResponseCreator... delegates) {
        this.delegates = delegates;
    }

    @Override
    public ClientHttpResponse createResponse(final ClientHttpRequest request) throws IOException {
        ClientHttpResponse ret = this.delegates[this.toExecute % this.delegates.length].createResponse(request);
        this.toExecute++;

        return ret;
    }

}

此委托人按顺序执行响应的委托人

因此，您可以模拟您想要的呼叫号码的响应

mockServer.expect(ExpectedCount.times(5), MockRestRequestMatchers.method(HttpMethod.GET))
            .andRespond(new DelegateResponseCreator(
                    MockRestResponseCreators.withServerError(), 
                    MockRestResponseCreators.withServerError(), 
                    MockRestResponseCreators.withServerError(), 
                    MockRestResponseCreators.withServerError(), 
                    MockRestResponseCreators.withSuccess()
                    ));

---

在本例中，前四个调用将返回服务器错误，而第五个调用将成功

您需要在发出所有请求后调用

mockServer.verify（）

，以检查是否满足期望。否则，您可以不提出任何请求而侥幸逃脱。

这就是最终对我有效的方法，测试的最大尝试次数为4次：

MockRestServiceServer server;

@Before
public void setUp() {
    server = MockRestServiceServer.bindTo(restTemplate).build();
}

@After
public void serverVerify() {
    server.verify();
}

@Test
public void doWork_retryThenSuccess() throws Exception {
    final String responseBody = "<some valid response JSON>";
    final String url = BASE_URL + "/doWork";
    server.expect(requestTo(url))
          .andExpect(MockRestRequestMatchers.method(HttpMethod.POST))
          .andRespond(ExceptionResponseCreator.withException(new SocketTimeoutException("first")));

    server.expect(requestTo(url))
          .andExpect(MockRestRequestMatchers.method(HttpMethod.POST))
          .andRespond(ExceptionResponseCreator.withException(new IOException("second")));

    server.expect(requestTo(url))
          .andExpect(MockRestRequestMatchers.method(HttpMethod.POST))
          .andRespond(ExceptionResponseCreator.withException(new RemoteAccessException("third")));

    server.expect(requestTo(url))
          .andExpect(MockRestRequestMatchers.method(HttpMethod.POST))
          .andRespond(withSuccess(responseBody, MediaType.APPLICATION_JSON));

    final MyResponseClass response = myService.call();

    assertThat(response, notNullValue());
    // other asserts here...
}

---

检查zed的答案是否准确。

package com.company.test;

import java.io.IOException;

import org.springframework.remoting.RemoteAccessException;
import org.springframework.test.web.client.ResponseCreator;
import org.springframework.test.web.client.response.MockRestResponseCreators;

public class ExceptionResponseCreator extends MockRestResponseCreators {
    public static ResponseCreator withException(IOException ex) {
        return request -> { throw ex; };
    }

    public static ResponseCreator withException(RemoteAccessException ex) {
        return request -> { throw ex; };
    }
}