如何模拟REST请求

问题描述

我正在JUnit中使用Mockito，并且我有一种使用 RestTemplate 向微服务发出请求的方法.

I am using Mockito in JUnit and I have a method making a request to a microservice using RestTemplate.

private static final String REQUESTOR_API_HOST = "http://localhost:8090/requestor/v1/requestors/";

public TokenRequestorPayload getTokenRequestor(Long id) {
    restClient = new RestTemplate();
    return restClient.getForObject(REQUESTOR_API_HOST + id, TokenRequestorPayload.class);
}

此方法返回一个JSON对象，该对象将在TokenRequestorPayload类中反序列化.

This method returns a JSON object which will be deserialize in TokenRequestorPayload class.

当我执行单元测试时，它们由于模拟不起作用而失败，并且我得到了 org.springframework.web.client.ResourceAccessException .如何模拟我的RestTemplate?

When I execute unit tests they fail because mock didn't work and I got a org.springframework.web.client.ResourceAccessException. How can I mock my RestTemplate?

测试

RestTemplate restTemplate = Mockito.spy(RestTemplate.class);
Mockito.doReturn(this.tokenRequestorMockJson()).when(restTemplate).getForObject(Mockito.anyString(), Mockito.eq(TokenRequestorPayload.class));

错误

推荐答案

在您的测试中，您正在为RestTemplate的模拟实例定义行为，这很好.

In your test you are defining behavior for a mock instance of RestTemplate, which is good.

RestTemplate restTemplate = Mockito.spy(RestTemplate.class);

但是，被测类没有使用相同的实例，被测类每次都创建一个新的RestTemplate实例并使用该实例.

However, the same instance is not used by the Class Under Test which creates a new RestTemplate instance each time and uses that one.

public TokenRequestorPayload getTokenRequestor(Long id, RestTemplate restClient) {
    restClient = new RestTemplate(); // it uses this instance, not the mock
    return restClient.getForObject(REQUESTOR_API_HOST + id, TokenRequestorPayload.class);
}

因此，您需要找到一种将模拟实例带入getTokenRequestor()方法的方法.

So you need to find a way to bring the mock instance to the getTokenRequestor() method.

例如，这可以通过将restClient转换为方法参数来实现:

E.g. this can be accomplished by turning restClient into a method parameter:

public TokenRequestorPayload getTokenRequestor(Long id, RestTemplate restClient) {
    return restClient.getForObject(REQUESTOR_API_HOST + id, TokenRequestorPayload.class);
}

，测试可能看起来像这样:

and the test might look something like like:

@Test
public void test() {
    RestTemplate restTemplateMock = Mockito.spy(RestTemplate.class);
    Mockito.doReturn(null).when(restTemplateMock).getForObject(Mockito.anyString(), Mockito.eq(TokenRequestorPayload.class));

    // more code

    instance.getTokenRequestor(id, restTemplateMock); // passing in the mock
}

这篇关于如何模拟REST请求的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！