Java EE 7 - JAX-RS Bean Validation - Query Parameter

UserResource.java

@Path("/users")
public class UserResource {
	...
	@GET
	@Path("/username-unique")
	public Response isEmailUnique(
		@QueryParam("name") 
		@NotNull 
		@Size(min=3, max=10, message="Der Name muss zwischen {min} und {max} Zeichen lang sein")
		String username) {
		
		// Check E-Mail Address in DB..
		return Response.ok().build();
	}
}