REST how to pass empty path parameter?

问题:

I'm building REST web app using Netbean 7.1.1 Glassfish 3.1.2

I have 2 URL:

"http://myPage/resource/getall/name"  (get some data by name)

"http://myPage/resource/getall" (get all data)

When client sends request using first URL, the servlet below is called and do some process.

@Path("getall/{name}")
@GET
@Produces("application/json")
public Object Getall(@PathParam("name") String customerName) {
      //here I want to call SQL if customerName is not null. is it possible???
}

But I also want second URL to call this servlet.

I thought the servlet would be called and I can just check customerName == null and then call different SQL and so on.

But when client sends request using second URL (i.e. without path parameter), the servlet is not being called because the URL does not have {name} path parameter.

Is it not possible to call second URL and invoke the servlet above?

One alternative I can think of is to use query parameter:

http://myPage/resource/getall?name=value

Maybe I can parse it and see if "value" is null then take action accordingly..

回答1:

You can specify a regular expression for your Path Parameter (see 2.1.1. @Path).

If you use .* matches both empty and non empty names So if you write:

@GET
@Path("getall/{name: .*}")
@Produces("application/json")
public Object Getall(@PathParam("name") String customerName) {
      //here I want to call SQL if customerName is not null. is it possible???
}

it will match both "http://myPage/resource/getall" and "http://myPage/resource/getall/name".

回答2:

@GET
@Path("getall{name:(/[^/]+?)?}")
@Produces("application/json")
public Object Getall(@PathParam("name") String customerName) {
  //here I want to call SQL if customerName is not null. is it      

 possible??? 
  }