Spring RestTemplate 映射 JSON 对 Map 的响应抛出 MismatchedInputException

Question

我正在尝试将 JSON 从 Github 的提交详细信息 API 解析为 HashMap。我在测试中使用的示例 Json 是 here

测试代码为

@SpringJUnitConfig(classes = {GithubApiService.class, RestTemplateConfiguration.class})
@EnableAutoConfiguration
public class GithubApiServiceTest {

    @Test
    public void testGithubResponseJsonToMapConversion(
            @Autowired RestTemplate restTemplate,
            @Autowired GithubApiService service,
            @Value("classpath:github/commit-payload.json") Resource commitPayloadFile) throws IOException {

        final String COMMITS_URL = "https://api.github.com/repos/Codertocat/Hello-World/commits/sha";

        //Stub response from Github Server
        String responseJson = new ObjectMapper().writeValueAsString(
                new String(Files.readAllBytes(Paths.get(commitPayloadFile.getFile().getAbsolutePath()))));
        MockRestServiceServer mockGithubServer = MockRestServiceServer.createServer(restTemplate);
        mockGithubServer.expect(requestTo(COMMITS_URL))
                .andRespond(withSuccess().contentType(APPLICATION_JSON).body(responseJson));

        //Call API Service
        Map<String, Object> result = service.getCommitDetails(COMMITS_URL);
        //Expect return type is hashmap
        assertThat(result.get("sha")).isEqualTo("6dcb09b5b57875f334f61aebed695e2e4193db5e");
    }
}

服务代码是

@Service
@AllArgsConstructor(onConstructor = @__(@Autowired))
public class GithubApiService {

    @Autowired
    private final RestTemplate restTemplate;

    public Map<String, Object> getCommitDetails(String commitsUrl) {
        ParameterizedTypeReference<Map<String, Object>> responseType = new ParameterizedTypeReference<Map<String, Object>>() {
        };
        RequestEntity<Void> request = RequestEntity.get(URI.create(commitsUrl)).accept(APPLICATION_JSON).build();
        return restTemplate.exchange(request, responseType).getBody();
    }
}

将 JSON 响应转换为 Map 失败并出现以下错误 (full log here)

Caused by: com.fasterxml.jackson.databind.exc.MismatchedInputException: Cannot construct instance of `java.util.LinkedHashMap` (although at least one Creator exists): no String-argument constructor/factory method to deserialize from String value ('{
  "url": "https://api.github.com/repos/octocat/Hello-World/commits/6dcb09b5b57875f334f61aebed695e2e4193db5e",
  "sha": "6dcb09b5b57875f334f61aebed695e2e4193db5e",
  "node_id": "MDY6Q29tbWl0NmRjYjA5YjViNTc4NzVmMzM0ZjYxYWViZWQ2OTVlMmU0MTkzZGI1ZQ==",
  "html_url": "https://github.com/octocat/Hello-World/commit/6dcb09b5b57875f334f61aebed695e2e4193db5e",
  "comments_url": "https://api.github.com/repos/octocat/Hello-World/commits/6dcb09b5b57875f334f61aebed695e2e4193db5e/comments",

因为我使用的是 spring-boot-starter-web 它会自动连接转换器，包括 MappingJackson2HttpMessageConverter 但调试器显示响应正在由 ByteArrayHttpMessageConverter 处理，尽管将内容类型设置为 application/json.

Answer 1

糟糕，我应该使用 @EnableAutoConfiguration 的 @RestClientTest 注释来解决问题。

@EnableAutoConfiguration 是一个更通用的注释，它没有实现 @RestClientTest 所做的所有自动配置

Spring RestTemplate 映射 JSON 对 Map 的响应抛出 MismatchedInputException

Spring RestTemplate Mapping JSON response to Map throws MismatchedInputException

java

spring

spring-mvc

spring-boot

jackson-databind