Adding a query to a URL that already has a question mark with Retrofit - kotlin

Question

By good design, Retrofit will add your query to your URL as an ampersand rather than a question mark if there's already a question mark in the URL. However, I have no control over the URL and so am unable to change it. Is there a way that I can override #Query so that it will use a ? instead?
interface Service {
#GET("/php/project/?sign.externalGetToken")
fun getAuthToken(
#Query("site") site: String,
#Query("time") time: String,
#Query("secretkey") secretKey: String
): Call<TokenResponse>
}
Printed URL:
http://baseurl.com/php/project/?sign.get&site=my_site&time=1538755984978&secretkey=site_secret_key
I need that URL to be:
http://baseurl.com/php/project/?sign.get?site=my_site&time=1538755984978&secretkey=site_secret_key
Note the double ? in ?sign.get?site.

Answer 1

Is an url like this acceptable ?
http://baseurl.com/php/project/?sign.get?&site=my_site&time=1538755984978&secretkey=site_secret_key
There is an & just after the second question mark, but in theory the server should still be able to read it. If yes you can do it simply like this:
#GET("/php/project/?sign.externalGetToken?")
Or you can also try like this:
#GET("/php/project/?sign.externalGetToken")
fun getAuthToken(
#Query(value = "?site", encoded = true) site: String, // encoded ensure that retrofit doesn't encode the ? into '%3F'
#Query("time") time: String,
#Query("secretkey") secretKey: String
): Call<TokenResponse>
which will result in
http://baseurl.com/php/project/?sign.get&?site=my_site&time=1538755984978&secretkey=site_secret_key
the & will this time be before the question mark, but not sure if it will work. Also this second solution requires you never pass null for the site parameter of your call, else the "?site" will simply not be printed.
As a last resort, if nothing of the above works, you can try to use instead the #Url annotation from retrofit. It seems a little in contradiction with the use of a service interface if you ask me, but at least it should work.
Just replace your declaration by this:
#GET
fun getAuthToken(
#Url url: String,
#Query("time") time: String,
#Query("secretkey") secretKey: String
): Call<TokenResponse>
then just call it like this
service.getAuthToken("/php/project/?sign.externalGetToken?site="+ yourSite, yourTimeString, yourSecretKey");
and you will have the url you want. But it requires to always send the url as a parameter.