Getting Header from Response (Retrofit / OkHttp Client)
In Retrofit 2.0.0, you can get header like this:
public interface Api {
@GET("user")
Call<User> getUser();
}
Call<User> call = api.getUser();
call.enqueue(new Callback<User>() {
@Override
public void onResponse(Call<User> call, Response<User> response) {
// get headers
Headers headers = response.headers();
// get header value
String cookie = response.headers().get("Set-Cookie");
// TODO
}
@Override
public void onFailure(Call<User> call, Throwable t) {
// TODO
}
});
Much like you I wanted the headers along side of the payload. I needed access to the Etag. It takes some retro-foo, but you can do it. here's what I did. It's a dirty sample so dont take this as a best practices sample.
public static RestAdapter.Builder getRestBuilder(Context context) {
GsonBuilder gsonBuilder = GsonBuilderUtils.getBuilder();
Gson gson = gsonBuilder.create();
// **
// 1. create our own custom deserializer here
// **
final MyGsonConverter gsonConverter = new MyGsonConverter(gson);
OkHttpClient httpClient = MyPersonalOkHttpFactory.getInstance().getAuthHttpClient(context);
httpClient.networkInterceptors().add(new Interceptor() {
@Override
public Response intercept(Chain chain) throws IOException {
Request originalRequest = chain.request();
Response response = chain.proceed(originalRequest);
// **
// 2. add the headers from the Interceptor to our deserializer instance
// **
gsonConverter.headers = response.headers();
return response;
}
});
RestAdapter.Builder builder = new RestAdapter.Builder()
.setClient(new OkClient(httpClient))
.setEndpoint(Common.getApiOriginUrl())
.setConverter(gsonConverter);
return builder;
}
private static class MyGsonConverter extends GsonConverter {
private Headers headers;
public MyGsonConverter(Gson gson) {
super(gson);
}
@Override
public Object fromBody(TypedInput body, Type type) throws ConversionException {
Object obj = super.fromBody(body, type);
// **
// 3. at this point, gson is called and you have access to headers
// do whatever you want here. I just set it on the return object.
// **
if (obj instanceof HeadersArrayList) {
((HeadersArrayList)obj).setHeaders(headers);
}
return obj;
}
}
public class HeadersArrayList<K> extends ArrayList<K>{
private Headers headers;
public Headers getHeaders() {
return headers;
}
public void setHeaders(Headers headers) {
this.headers = headers;
}
}
// the retrofit api for reference
@GET("/api/of/my/backend/{stuff}")
HeadersArrayList<String> getSomething(@Path("stuff") String stuff);
With Retrofit 1.9.0, if you use the Callback asynchronous version of the interface,
@GET("/user")
void getUser(Callback<User> callback)
Then your callback will receive a Response
object
Callback<User> user = new Callback<User>() {
@Override
public void success(User user, Response response) {
}
@Override
public void failure(RetrofitError error) {
}
}
Which has a method called getHeaders()
Callback<User> user = new Callback<User>() {
@Override
public void success(User user, Response response) {
List<Header> headerList = response.getHeaders();
for(Header header : headerList) {
Log.d(TAG, header.getName() + " " + header.getValue());
}
}
For Retrofit 2.0's interface, you can do this with Call<T>
.
For Retrofit 2.0's Rx support, you can do this with Observable<Result<T>>