Package javax.ws.rs.ext

Interface MessageBodyWriter<T>

  • public interface MessageBodyWriter<T>
    Contract for a provider that supports the conversion of a Java type to a stream. To add a MessageBodyWriter implementation, annotate the implementation class with @Provider. A MessageBodyWriter implementation may be annotated with Produces to restrict the media types for which it will be considered suitable.
    See Also:
    Provider, Produces

    • Method Summary

      All Methods Instance Methods Abstract Methods 
      Modifier and Type Method Description
      long getSize​(T t, java.lang.Class<?> type, java.lang.reflect.Type genericType, java.lang.annotation.Annotation[] annotations, MediaType mediaType)
      Called before writeTo to ascertain the length in bytes of the serialized form of t.
      boolean isWriteable​(java.lang.Class<?> type, java.lang.reflect.Type genericType, java.lang.annotation.Annotation[] annotations, MediaType mediaType)
      Ascertain if the MessageBodyWriter supports a particular type.
      void writeTo​(T t, java.lang.Class<?> type, java.lang.reflect.Type genericType, java.lang.annotation.Annotation[] annotations, MediaType mediaType, MultivaluedMap<java.lang.String,​java.lang.Object> httpHeaders, java.io.OutputStream entityStream)
      Write a type to an HTTP response.

    • Method Detail

      • isWriteable

        boolean isWriteable​(java.lang.Class<?> type,
                    java.lang.reflect.Type genericType,
                    java.lang.annotation.Annotation[] annotations,
                    MediaType mediaType)
        Ascertain if the MessageBodyWriter supports a particular type.
        Parameters:
        type - the class of object that is to be written.
        genericType - the type of object to be written, obtained either by reflection of a resource method return type or via inspection of the returned instance. GenericEntity provides a way to specify this information at runtime.
        annotations - an array of the annotations on the resource method that returns the object.
        mediaType - the media type of the HTTP entity.
        Returns:
        true if the type is supported, otherwise false.

      • getSize

        long getSize​(T t,
             java.lang.Class<?> type,
             java.lang.reflect.Type genericType,
             java.lang.annotation.Annotation[] annotations,
             MediaType mediaType)
        Called before writeTo to ascertain the length in bytes of the serialized form of t. A non-negative return value is used in a HTTP Content-Length header.
        Parameters:
        t - the instance to write
        type - the class of object that is to be written.
        genericType - the type of object to be written, obtained either by reflection of a resource method return type or by inspection of the returned instance. GenericEntity provides a way to specify this information at runtime.
        annotations - an array of the annotations on the resource method that returns the object.
        mediaType - the media type of the HTTP entity.
        Returns:
        length in bytes or -1 if the length cannot be determined in advance

      • writeTo

        void writeTo​(T t,
             java.lang.Class<?> type,
             java.lang.reflect.Type genericType,
             java.lang.annotation.Annotation[] annotations,
             MediaType mediaType,
             MultivaluedMap<java.lang.String,​java.lang.Object> httpHeaders,
             java.io.OutputStream entityStream)
      throws java.io.IOException,
             WebApplicationException
        Write a type to an HTTP response. The response header map is mutable but any changes must be made before writing to the output stream since the headers will be flushed prior to writing the response body.
        Parameters:
        t - the instance to write.
        type - the class of object that is to be written.
        genericType - the type of object to be written, obtained either by reflection of a resource method return type or by inspection of the returned instance. GenericEntity provides a way to specify this information at runtime.
        annotations - an array of the annotations on the resource method that returns the object.
        mediaType - the media type of the HTTP entity.
        httpHeaders - a mutable map of the HTTP response headers.
        entityStream - the OutputStream for the HTTP entity. The implementation should not close the output stream.
        Throws:
        java.io.IOException - if an IO error arises
        WebApplicationException - if a specific HTTP error response needs to be produced. Only effective if thrown prior to the response being committed.