Spring MVC：使用HttpMessageConverters正确配置WebMvcConfigurerAdapter

Question

使用Spring Framework 4.3.6

关于MVC，声明：

@EnableWebMvc
@Configuration
public class WebMvcConfig extends WebMvcConfigurerAdapter {

使用：

@Override
public void configureMessageConverters(List<HttpMessageConverter<?>> converters) {
   converters.add(httpMessageConverterConfig.stringHttpMessageConverter());
   converters.add(httpMessageConverterConfig.mappingJackson2XmlHttpMessageConverter());
   converters.add(httpMessageConverterConfig.mappingJackson2HttpMessageConverter());
}

因此：

1. 字符串
2. XML
3. 的Json

对于某些@Test方法失败

在哪里工作：

resultActions = mockMvc.perform(get(uri).accept(MediaType.APPLICATION_JSON_UTF8))
                    .andDo(print());

感谢：.andDo(print());我可以看到以下内容：

MockHttpServletRequest:
      HTTP Method = GET
      Request URI = /personas
       Parameters = {}
          Headers = {Accept=[application/json;charset=UTF-8]}

Handler:
             Type = ....
           Method = public com.manuel....

Async:
    Async started = false
     Async result = null

Resolved Exception:
             Type = null

ModelAndView:
        View name = null
             View = null
            Model = null

FlashMap:
       Attributes = null

MockHttpServletResponse:
           Status = 200
    Error message = null
          Headers = {Content-Type=[application/json;charset=UTF-8]}
     Content type = application/json;charset=UTF-8
             Body = <collection>
  <item>
    <id>087</id>
    <nombre>Leonardo</nombre>
    <apellido>Jordan</apellido>
  </item>
  ....
</collection>

观察：

• 对于MockHttpServletRequest和MockHttpServletRequest标题是正确的。两者都与JSON
相关
• 对于MockHttpServletRequest，即使标题与JSON相关，请注意正文位于XML。

因此错误信息是：

java.lang.AssertionError: No value at JSON path "collection", exception: Property ['collection'] not found in path $
    at org.springframework.test.util.JsonPathExpectationsHelper.evaluateJsonPath(JsonPathExpectationsHelper.java:245)

如果客户是RestTemplate

通过以下方式定义或创建：

RestTemplate restTemplate = new RestTemplate(new MockMvcClientHttpRequestFactory(mockMvc));

使用：

requestEntity = RequestEntity.get(uri).accept(MediaType.APPLICATION_JSON_UTF8)
                                                      .build();

错误是：

org.springframework.http.converter.HttpMessageNotReadableException: Could not read document: Unexpected character ('<' (code 60)): expected a valid value (number, String, array, object, 'true', 'false' or 'null')
 at [Source: java.io.ByteArrayInputStream@5874adee; line: 1, column: 2]; nested exception is com.fasterxml.jackson.core.JsonParseException: Unexpected character ('<' (code 60)): expected a valid value (number, String, array, object, 'true', 'false' or 'null')
 at [Source: java.io.ByteArrayInputStream@5874adee; line: 1, column: 2]

好奇的是：

@Override
public void configureMessageConverters(List<HttpMessageConverter<?>> converters) {
   converters.add(httpMessageConverterConfig.stringHttpMessageConverter());
   converters.add(httpMessageConverterConfig.mappingJackson2XmlHttpMessageConverter());
   converters.add(httpMessageConverterConfig.mappingJackson2HttpMessageConverter());
}

再次：

1. 字符串
2. XML
3. 的Json

更改为：

@Override
public void configureMessageConverters(List<HttpMessageConverter<?>> converters) {
   converters.add(httpMessageConverterConfig.stringHttpMessageConverter());
   converters.add(httpMessageConverterConfig.mappingJackson2HttpMessageConverter());
   converters.add(httpMessageConverterConfig.mappingJackson2XmlHttpMessageConverter());

}

1. 字符串
2. 的Json
3. XML

现在一切正常。因此，列表的顺序至关重要。

为什么会这样？ 还是缺少其他东西？

要求声明列表，无需项目的顺序和信任HTTP标头。