Package ca.uhn.fhir.rest.api.server

Interface IRestfulResponse

All Known Implementing Classes:
BaseRestfulResponse, ServletRestfulResponse, SystemRestfulResponse
public interface IRestfulResponse
Implementations of this interface represent a response back to the client from the server. It is conceptually similar to HttpServletResponse but intended to be agnostic of the server framework being used.

This class is a bit of an awkward abstraction given the two styles of servers it supports. Servlets work by writing to a servlet response that is provided as a parameter by the container. JAX-RS works by returning an object via a method return back to the containing framework. However using it correctly should make for compatible code across both approaches.

  • Method Details

    • getResponseWriter

      @Nonnull Writer getResponseWriter(int theStatusCode, String theContentType, String theCharset, boolean theRespondGzip) throws IOException
      Initiate a new textual response. The Writer returned by this method must be finalized by calling commitResponse(Closeable) later.

      Note that the caller should not close the returned object, but should instead just return it to commitResponse(Closeable) upon successful completion. This is different from normal Java practice where you would request it in a try with resource block, since in Servlets you are not actually required to close the writer/stream, and doing so automatically may prevent you from correctly handling exceptions.

      Parameters:
      theStatusCode - The HTTP status code.
      theContentType - The HTTP response content type.
      theCharset - The HTTP response charset.
      theRespondGzip - Should the response be GZip encoded?
      Returns:
      Returns a Writer that can accept the response body.
      Throws:
      IOException

    • getResponseOutputStream

      @Nonnull OutputStream getResponseOutputStream(int theStatusCode, String theContentType, @Nullable Integer theContentLength) throws IOException
      Initiate a new binary response. The OutputStream returned by this method must be finalized by calling commitResponse(Closeable) later. This method should only be used for non-textual responses, for those use getResponseWriter(int, String, String, boolean).

      Note that the caller should not close the returned object, but should instead just return it to commitResponse(Closeable) upon successful completion. This is different from normal Java practice where you would request it in a try with resource block, since in Servlets you are not actually required to close the writer/stream, and doing so automatically may prevent you from correctly handling exceptions.

      Parameters:
      theStatusCode - The HTTP status code.
      theContentType - The HTTP response content type.
      theContentLength - If known, the number of bytes that will be written. null otherwise.
      Returns:
      Returns an OutputStream that can accept the response body.
      Throws:
      IOException

    • commitResponse

      Object commitResponse(@Nonnull Closeable theWriterOrOutputStream) throws IOException
      Finalizes the response streaming using the writer that was returned by calling either getResponseWriter(int, String, String, boolean) or getResponseOutputStream(int, String, Integer). This method should only be called if the response writing/streaming actually completed successfully. If an error occurred you do not need to commit the response.
      Parameters:
      theWriterOrOutputStream - The Writer or OutputStream that was returned by this object, or a Writer/OutputStream which decorates the one returned by this object.
      Returns:
      If the server style requires a returned response object (i.e. JAX-RS Server), this method returns that object. If the server style does not require one (i.e. RestfulServer), this method returns null.
      Throws:
      IOException

    • addHeader

      void addHeader(String headerKey, String headerValue)
      Adds a response header. This method must be called prior to calling getResponseWriter(int, String, String, boolean) or getResponseOutputStream(int, String, Integer).
      Parameters:
      headerKey - The header name
      headerValue - The header value

    • getHeaders

      Map<String,List<String>> getHeaders()
      Returns the headers added to this response