REST如何在URI中传递空路径参数？

Question

I am developing a restful webapp. In this the parameters i take are userid and orderid.

The userid can be null .
The URI is @Path("api/user/userid/order/orderid") My method is,

void add(@PathParam("userid") String userId, @PathParam("orderid") String orderId);

I want to pass null value for userId in the URI.

I tried api/user//order/1234 . But in this case, the userid takes the value of orderId (ie 1234 and orderId is null . (which is wrong)

I also tried changing the path as @Path("api/user/userid: .*/order/orderid") . Yet the same result as previous.

The other ways for solving this could be, using @QueryParam for userid or creating another method for userid null .

But I would like to know if there is a way to have userId as PathParameter instead of QueryParam and pass the value of userid as null ?

Answer 1

Having a URL param as null is not a valid case.

POSTing to the URL api/user/userid/order/orderid is saying "create an order for this user". GETting to that same URL would be saying "retrieve me this specific order for this user". Both are in the context of a user.

For doing order creation or retrieval outside of the context of a user, just remove those two parts of your URL...

api/order/orderid

This would allow you to create and get orders outside of the bounds of a customer. This would also work for in the context of a user. If you POST an order with no userID, nobody cares, but one can be specified. And if you GET an order, it shouldn't care which customer it is for, unless your orderID isn't unique across customers but that is probably not a good idea but that is a separate discussion.