Spring @即使Accept定义为null，也会调用GetMapping

我正在使用Spring框架

4.3.13.RELEASE

关于Rest，对于

POST

，我有以下内容：

@Controller
@RequestMapping(path="/personas")
public class PersonaRestController {

    @PostMapping(consumes={MediaType.APPLICATION_XML_VALUE, MediaType.APPLICATION_JSON_UTF8_VALUE})
    public ResponseEntity<Void> saveOne(
            @Validated @RequestBody Persona persona, ...

MockHttpServletRequest:
      HTTP Method = POST
      Request URI = /personas
       Parameters = {}
          Headers = {}

Handler:
             Type = null

Async:
    Async started = false
     Async result = null

Resolved Exception:
             Type = org.springframework.web.HttpMediaTypeNotSupportedException

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

FlashMap:
       Attributes = null

MockHttpServletResponse:
           Status = 415
    Error message = null
          Headers = {Accept=[application/xml, application/json;charset=UTF-8]}
     Content type = null
             Body = 
    Forwarded URL = null
   Redirected URL = null
          Cookies = []

@GetMapping(path="/{id}",
            produces={MediaType.APPLICATION_XML_VALUE, MediaType.APPLICATION_JSON_UTF8_VALUE})
public @ResponseBody Persona findOneById(@PathVariable String id){
    return personaService.findOneById(id);
}

MockHttpServletRequest:
      HTTP Method = GET
      Request URI = /personas/100
       Parameters = {}
          Headers = {}

Handler:
             Type = com.manuel.jordan.rest.persona.PersonaRestController
           Method = public com.manuel.jordan.domain.Persona com.manuel.jordan.rest.persona.PersonaRestController.findOneById(java.lang.String)

因为

saveOne

方法要求内容数据为

XML

或

JSON

，所以可以感觉到这种行为，并且对于此测试场景，

content Type

未被发送

因此，预计Spring会出现一个

HttpMediaTypeNotSupportedException

实例。然后，

@Test

方法失败，出现

java.lang.AssertionError:No handler

错误消息，因为没有处理程序来处理用户请求

直到这里一切都好

同样，关于Rest，对于

GET

，我有以下内容：

@Controller
@RequestMapping(path="/personas")
public class PersonaRestController {

    @PostMapping(consumes={MediaType.APPLICATION_XML_VALUE, MediaType.APPLICATION_JSON_UTF8_VALUE})
    public ResponseEntity<Void> saveOne(
            @Validated @RequestBody Persona persona, ...

MockHttpServletRequest:
      HTTP Method = POST
      Request URI = /personas
       Parameters = {}
          Headers = {}

Handler:
             Type = null

Async:
    Async started = false
     Async result = null

Resolved Exception:
             Type = org.springframework.web.HttpMediaTypeNotSupportedException

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

FlashMap:
       Attributes = null

MockHttpServletResponse:
           Status = 415
    Error message = null
          Headers = {Accept=[application/xml, application/json;charset=UTF-8]}
     Content type = null
             Body = 
    Forwarded URL = null
   Redirected URL = null
          Cookies = []

@GetMapping(path="/{id}",
            produces={MediaType.APPLICATION_XML_VALUE, MediaType.APPLICATION_JSON_UTF8_VALUE})
public @ResponseBody Persona findOneById(@PathVariable String id){
    return personaService.findOneById(id);
}

MockHttpServletRequest:
      HTTP Method = GET
      Request URI = /personas/100
       Parameters = {}
          Headers = {}

Handler:
             Type = com.manuel.jordan.rest.persona.PersonaRestController
           Method = public com.manuel.jordan.domain.Persona com.manuel.jordan.rest.persona.PersonaRestController.findOneById(java.lang.String)

对于其他测试场景，请执行以下操作：

@Controller
@RequestMapping(path="/personas")
public class PersonaRestController {

    @PostMapping(consumes={MediaType.APPLICATION_XML_VALUE, MediaType.APPLICATION_JSON_UTF8_VALUE})
    public ResponseEntity<Void> saveOne(
            @Validated @RequestBody Persona persona, ...

MockHttpServletRequest:
      HTTP Method = POST
      Request URI = /personas
       Parameters = {}
          Headers = {}

Handler:
             Type = null

Async:
    Async started = false
     Async result = null

Resolved Exception:
             Type = org.springframework.web.HttpMediaTypeNotSupportedException

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

FlashMap:
       Attributes = null

MockHttpServletResponse:
           Status = 415
    Error message = null
          Headers = {Accept=[application/xml, application/json;charset=UTF-8]}
     Content type = null
             Body = 
    Forwarded URL = null
   Redirected URL = null
          Cookies = []

@GetMapping(path="/{id}",
            produces={MediaType.APPLICATION_XML_VALUE, MediaType.APPLICATION_JSON_UTF8_VALUE})
public @ResponseBody Persona findOneById(@PathVariable String id){
    return personaService.findOneById(id);
}

MockHttpServletRequest:
      HTTP Method = GET
      Request URI = /personas/100
       Parameters = {}
          Headers = {}

Handler:
             Type = com.manuel.jordan.rest.persona.PersonaRestController
           Method = public com.manuel.jordan.domain.Persona com.manuel.jordan.rest.persona.PersonaRestController.findOneById(java.lang.String)

我的拦截器显示以下数据

HttpHeaderControlInterceptor - preHandle 
   HttpServletRequest > 
    URL: http://localhost/personas/100 
    URI: /personas/100 
       HttpMethod: GET 
          Accept: null 
          Accept-Language: null 
          Content-Type: null 

我很困惑为什么

findOneById

方法在

Accept

为空时如何调用处理程序。我期望类似于

java.lang.AssertionError的东西：没有处理程序

错误消息，而是类，因为

findOneById

方法可以返回

XML

或

JSON

格式的数据

---

缺少什么？

我不太确定，但我猜这是由HTTP 1.1引起的

参见第10.4.7 406节-不可接受

注意：允许HTTP/1.1服务器返回以下响应： 根据中发送的accept标头，不可接受 要求在某些情况下，这甚至可能比发送 406答复。鼓励用户代理检查 确定其是否可接受的传入响应

我认为，

消费

与

生产

的处理方式是不同的，这就是为什么你会看到差异

请参阅此问题

我之前已经发布了一个答案，我已经删除了。基本上，我误解了你的问题