Retrofit: multiple query parameters in @GET command?

I am using Retrofit and Robospice to make API calls in my android application. All @POST methods work great, and so do @GET commands without any parameters in the URL, but I can't get any @GET calls to work with parameters on the end!

For example, if my API path was "my/api/call/" and I wanted 2 parameters "param1" and "param2" in the URL, the get call would look like:

http://www.example.com/my/api/call?param1=value1&param2=value2

so I have setup my @GET interface like so:

@GET("/my/api/call?param1={p1}&param2={p2}")
Response getMyThing(@Path("p1")
String param1, @Path("p2")
String param2);

but I get an error saying
"An exception occurred during request network execution : URL query string "/my/api/call?param1={p1}&param2={p2}" on method getMyThing may not have replaced block."

What am I doing wrong?

You should be using this syntax:

@GET("/my/API/call")
Response getMyThing(
    @Query("param1") String param1,
    @Query("param2") String param2);

Specifying query parameters in the URL is only for when you know both the key and value and they are fixed.

If you have a bunch of GET params, another way to pass them into your url is a HashMap.

class YourActivity extends Activity {

    private static final String BASEPATH = "http://www.example.com";

    private interface API {
        @GET("/thing")
        void getMyThing(@QueryMap Map<String, String>, new Callback<String> callback);
    }

    public void onCreate(Bundle savedInstanceState) {
       super.onCreate(savedInstanceState);
       setContentView(R.layout.your_layout);

       RestAdapter rest = new RestAdapter.Builder().setEndpoint(BASEPATH).build();
       API service      = rest.create(API.class);

       Map<String, String> params = new HashMap<String, String>();
       params.put("foo", "bar");
       params.put("baz", "qux");
       // ... as much as you need.
   
       service.getMyThing(params, new Callback<String>() {
           // ... do some stuff here.
       });
    }
}

The URL called will be http://www.example.com/thing/?foo=bar&baz=qux

You can create a Map of params and send it like below:

Map<String, String> paramsMap = new HashMap<String, String>();
paramsMap.put("p1", param1);
paramsMap.put("p2", param2);

// Inside call
@GET("/my/api/call")
Response getMyThing(@QueryMap Map<String, String> paramsMap);

Do not write your Query params in GET-URL. Do it like this:

@GET("/my/api/call")
Response getMyThing(@Query("param1") String param1,
                    @Query("param2") String param2);

with Java

@GET("/my/api/call")
Response getMyThing(@Query("p1")
String param1, @Query("p2")
String param2);

with Kotlin coroutines

 @GET("/my/api/call")
 suspend fun getSearchProduct(@Query("p1") p1: String , @Query("p2") p2: String )

This is the best way you can use:

@GET("api_link_put_here")
    apiResponse getMyData(
            @Query("first_param") String firstParam,
            @Query("second_param") String secondParam
    );

this will automatically work like: http://baseurl.com/api_link_put_here?first_param=firstParam&second_param=secondParam