Spring MVC中获取不到请求消息体

后端通过HttpServletRequest.getInputStream获取消息体时，发现读取不出，代码如下：

    @PostMapping("/test2")
    public String test2(HttpServletRequest request) throws IOException {
        BufferedReader reader=new BufferedReader(new InputStreamReader(request.getInputStream(),"utf-8"));
        String str=null;
        while((str=reader.readLine())!=null){
            System.out.println(str);
        }
        return "ok";
    }

然后使用curl命令发起请求：

$ curl -v --data "name=tom&password=123456" http://localhost:8080/test2
*   Trying ::1...
* TCP_NODELAY set
* Connected to localhost (::1) port 8080 (#0)
> POST /test2 HTTP/1.1
> Host: localhost:8080
> User-Agent: curl/7.58.0
> Accept: */*
> Content-Length: 24
> Content-Type: application/x-www-form-urlencoded
>
* upload completely sent off: 24 out of 24 bytes
< HTTP/1.1 200
< Content-Type: text/plain;charset=UTF-8
< Content-Length: 2
< Date: Wed, 05 Jun 2019 08:28:51 GMT
<
* Connection #0 to host localhost left intact
ok

然而后端无输出，这是因为Spring MVC检测到Content-Type: application/x-www-form-urlencoded，已经先一步读取并解析了。因此后端可用下列方法读取：

@PostMapping("/test")
public String test(String name,String password) throws IOException {
    System.out.println(name);
    System.out.println(password);
    return "ok";
}

如果非要使用HttpServletRequest.getInputStream读取请求消息体呢？那就防止Spring MVC预先读取就行了，比如设置Content-Type: text/*，代码如下所示：

$ curl -v --data "bbbbb" -H "Content-Type: text/*" http://localhost:8080/test2
*   Trying ::1...
* TCP_NODELAY set
* Connected to localhost (::1) port 8080 (#0)
> POST /test2 HTTP/1.1
> Host: localhost:8080
> User-Agent: curl/7.58.0
> Accept: */*
> Content-Type: text/*
> Content-Length: 5
>
* upload completely sent off: 5 out of 5 bytes
< HTTP/1.1 200
< Content-Type: text/plain;charset=UTF-8
< Content-Length: 2
< Date: Wed, 05 Jun 2019 08:31:28 GMT
<
* Connection #0 to host localhost left intact
ok

此时后端能够正确打印bbbb了。