Annotation Type Multipart


@Documented @Retention(RUNTIME) @Target(METHOD) public @interface Multipart
Marks a method as sending a multipart/form-data body built from its @Part/@PartMap-annotated parameters, instead of the JSON/raw-string body a @Body parameter would send. Valid only on @POST, @PUT, @PATCH, and @DELETE methods - using it on @GET, @HEAD, or @OPTIONS fails validation, same as @Body. A method can't combine @Multipart with a @Body parameter, and needs at least one @Part/ @PartMap parameter to be worth declaring multipart at all.
@POST("/users/{id}/avatar")
 @Multipart
 String uploadAvatar(@PathParam("id") String id, @Part("file") File avatar);