ShallowEtagHeaderFilter should write body early when HttpServletResponse.sendError() is called [SPR-11705]

[spring-projects-issues]

Dmitry Goncharov opened SPR-11705 and commented

Third party Servlet (in my case it's Jersey 2) is wrapped by org.springframework.web.filter.ShallowEtagHeaderFilter

In some cases Servlet need to write custom error response. Servlet do it in following way: add headers, write error response body and send error response code by calling response.sendError() method.

ShallowEtagHeaderFilter postpone response body writing, so actual body writing is performed in ShallowEtagHeaderFilter#copyBodyToResponse
after sendError method invocation.
response.sendError commits wrapped response, therefore ShallowEtagHeaderFilter#copyBodyToResponse is performed on committed response. This leads to wrong response content.

Proposed solution: Force content writing in org.springframework.web.filter.ShallowEtagHeaderFilter.ShallowEtagResponseWrapper when sendError or sendRedirect is called.

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Affects: 3.0.5

Issue Links:

• ShallowEtagHeaderFilter setContentLength on include [SPR-11717] #16339 ShallowEtagHeaderFilter setContentLength on include
• ContentCachingResponseWrapper should NOT sendError() before write body [SPR-13004] #17596 ContentCachingResponseWrapper should NOT sendError() before write body

[spring-projects-issues]

Juergen Hoeller commented

It's a little unusual to write body content first and then call sendError... since sendError is supposed to trigger the container's error page. If all you wanted is an error status code with custom content, you'd use setStatus instead.

In any case, since Jersey does it that way, we're going to support it in ShallowEtagHeaderFilter as of Spring 4.0.4.

Juergen