Package org.springframework.messaging.handler.annotation.support

Class MessageMethodArgumentResolver

java.lang.Object
org.springframework.messaging.handler.annotation.support.MessageMethodArgumentResolver
All Implemented Interfaces:
HandlerMethodArgumentResolver
public class MessageMethodArgumentResolver extends Object implements HandlerMethodArgumentResolver
HandlerMethodArgumentResolver for Message method arguments. Validates that the generic type of the payload matches to the message value or otherwise applies MessageConverter to convert to the expected payload type.
Since:
4.0
Author:
Rossen Stoyanchev, Stephane Nicoll, Juergen Hoeller

  • Constructor Details

    • MessageMethodArgumentResolver

      public MessageMethodArgumentResolver()
      Create a default resolver instance without message conversion.

    • MessageMethodArgumentResolver

      public MessageMethodArgumentResolver(@Nullable MessageConverter converter)
      Create a resolver instance with the given MessageConverter.
      Parameters:
      converter - the MessageConverter to use (may be null)
      Since:
      4.3

  • Method Details

    • supportsParameter

      public boolean supportsParameter(MethodParameter parameter)
      Description copied from interface: HandlerMethodArgumentResolver
      Whether the given method parameter is supported by this resolver.
      Specified by:
      supportsParameter in interface HandlerMethodArgumentResolver
      Parameters:
      parameter - the method parameter to check
      Returns:
      true if this resolver supports the supplied parameter; false otherwise

    • resolveArgument

      public Object resolveArgument(MethodParameter parameter, Message<?> message) throws Exception
      Description copied from interface: HandlerMethodArgumentResolver
      Resolves a method parameter into an argument value from a given message.
      Specified by:
      resolveArgument in interface HandlerMethodArgumentResolver
      Parameters:
      parameter - the method parameter to resolve. This parameter must have previously been passed to HandlerMethodArgumentResolver.supportsParameter(org.springframework.core.MethodParameter) which must have returned true.
      message - the currently processed message
      Returns:
      the resolved argument value, or null
      Throws:
      Exception - in case of errors with the preparation of argument values

    • getPayloadType

      protected Class<?> getPayloadType(MethodParameter parameter, Message<?> message)
      Resolve the target class to convert the payload to.

      By default this is the generic type declared in the Message method parameter but that can be overridden to select a more specific target type after also taking into account the "Content-Type", e.g. return String if target type is Object and "Content-Type:text/**".

      Parameters:
      parameter - the target method parameter
      message - the message being processed
      Returns:
      the target type to use
      Since:
      5.2

    • isEmptyPayload

      protected boolean isEmptyPayload(@Nullable Object payload)
      Check if the given payload is empty.
      Parameters:
      payload - the payload to check (can be null)