In HTTP 1.1 a special "Transfer-Encoding: chunked" header
enables splitting the request to smaller parts.
When this mode is enabled, Multipart requests used for uploading data
via REST API are handled incorrectly.
- Create a new KB Article
- In IDEA, add Vulcan Impl dependency to any custom module to be
able to set a breakpoint, see next step
implementation 'com.liferay:com.liferay.portal.vulcan.impl:5.0.68'
- In IDEA set a breakpoint inside readFrom() method of the
MultipartBodyMessageBodyReader class
- Add KB article attachment using REST API with and without checked
encoding:
(for demonstration purposes just key=value form params
are passed):
curl -X POST
"http://localhost:8080/o/headless-delivery/v1.0/knowledge-base-articles/84163002/knowledge-base-attachments"
-H "Content-Type: multipart/form-data" -F
"key=value" -u "test@liferay.com:test"
curl -X POST
"http://localhost:8080/o/headless-delivery/v1.0/knowledge-base-articles/84163002/knowledge-base-attachments"
-H "Content-Type: multipart/form-data" -F
"key=value" -H "Transfer-Encoding:
chunked" -u "test@liferay.com:test"
- When the breakpoint is hit, inspect the fileItems list returned by
this line:
List<FileItem> fileItems =
servletFileUpload.parseRequest( _httpServletRequest);
When chunked encoding is used, the list is empty. It means any passed
params are discarded.
In some clients, like standard Java 11 HttpClient, it is not possible
to disable that chunked encoding, so this client cannot be used for
REST API calls at the moment.
