Package ca.uhn.fhir.rest.server.messaging

Interface IMessage<T>

Type Parameters:
T - the type of the message payload. In most cases, T will be a subclass of BaseJsonMessage
All Known Implementing Classes:
BaseJsonMessage, ResourceOperationJsonMessage
public interface IMessage<T>
This interface is implemented by serializable "wrapper" message classes that are exchanged with Massage Brokers. HAPI-FHIR message classes implement both Message and IMessage so that they can be exchanged with both JMS and non-JMS brokers. These message wrappers wrap a serializable payload that is the main content of the message. This wrapper also contains meta-data about the message such as headers and a message key. The message key is used by non-JMS brokers for partition selection.

  • Method Details

    • getMessageKey

      @Nonnull default String getMessageKey()
      The message key is used by brokers that support channel partitioning. The message key is used to determine which partition a message is stored on. If message order is important, then the same message key should be used for all messages that need to preserve their order. E.g. if a series of messages create, update, and delete a resource, the resource id would be a good candidate for the message key to ensure the order of operations is preserved on all messages concerning that resource.
      Returns:
      the key of the message.

    • getHeaders

      @Nonnull Map<String,Object> getHeaders()
      Returns:
      a map of message headers

    • getHeader

      default <H> Optional<H> getHeader(String theHeaderName)
      Returns:
      a header value as an Optional

    • getPayload

      T getPayload()
      Returns:
      the de-serialized value of the message

    • getHeadersAsStrings

      default Map<String,String> getHeadersAsStrings()
      Returns:
      headers as a String to String map where all values are replaced with their toString() value

    • convertHeaderValuesToStrings

      static Map<String,String> convertHeaderValuesToStrings(Map<String,Object> theHeaders)
      Converts a map of headers with Object values to a map with String values. This utility method converts all header values to their string representation using toString().
      Parameters:
      theHeaders - the headers map with Object values to convert
      Returns:
      a new map with the same keys but all values converted to strings