If you specify @GET("foobar?a=5")
, then any @Query("b")
must be appended using &
, producing something like foobar?a=5&b=7
.
If you specify @GET("foobar")
, then the first @Query
must be appended using ?
, producing something like foobar?b=7
.
That’s how Retrofit works.
When you specify @GET("foobar?")
, Retrofit thinks you already gave some query parameter, and appends more query parameters using &
.
Remove the ?
, and you will get the desired result.