HiddenHttpMethodFilter cause HttpServletRequest.getInputStream() is empty

[mrleoyoung]

org.springframework.web.filter.HiddenHttpMethodFilter, String paramValue = request.getParameter(this.methodParam); cause HttpServletRequest.getInputStream() will be empty in future.
and the filter is introduced by org.springframework.boot.autoconfigure.web.WebMvcAutoConfiguration, which is automatically enabled when using spring mvc in spring-boot

[wilkinsona]

HttpServletRequest.getInputStream() will be empty in future.

I don't believe that's always the case. AFAIK, the input stream will only be empty if it was a POST request with a content type of multipart/form-data or application/x-www-form-url-encoded. In those cases, the request's body is then available via getParameters() or getParts() so there's typically no need to use the input stream.

Can you provide some more information about the container that you're using, the type of request that you are sending, and why you need to use the input stream?

[mrleoyoung]

Well, I think a framework should not consume the IO data that can be consumed only once. We have a file sync service. when a file is ready, we use curl to post the file to our service. some thing like this:
my test post:
curl -X POST -H "Expect:" --data-binary @"test.jpg" "http://localhost:7001/upload"
my simple servlet in spring boot(spring mvc):
ByteArrayOutputStream outputStream = new ByteArrayOutputStream(); IOUtils.copy(request.getInputStream(), outputStream); byte[] data = outputStream.toByteArray();

actually, this issue is trying to fix the same problem as this one: https://github.com/spring-projects/spring-boot/commit/607dba97f8e3d69517924431678179b003d3d4a5

thanks.

[wilkinsona]

curl -X POST -H "Expect:" --data-binary @"test.jpg" "http://localhost:7001/upload"

This will upload the JPEG image using application/x-www-form-urlencoded as the Content-Type. That almost certainly isn't what you want and you'll see Tomcat fail to parse the parameters with an INFO message that begins:

2016-04-14 11:12:09.056  INFO 36165 --- [nio-8080-exec-3] org.apache.tomcat.util.http.Parameters   : Character decoding failed. Parameter

If you want to access the image data directly via the InputStream you should explicitly set the Content-Type:

curl http://localhost:7001/upload -H "Content-Type: image/jpeg" --data-binary @test.jpg 

Alternatively, you can make the data available via the request's parts by uploading it as multipart/form-data:

curl http://localhost:8080/upload -F image=@test.jpg