simple singleton to keep information on orientation change

AndroidRxInAction/app/src/main/java/com/nhpatt/androidrxinaction/MainActivity.java

@@ -6,15 +6,12 @@
 import android.support.v7.widget.RecyclerView;
 import android.support.v7.widget.Toolbar;
 
-import com.nhpatt.androidrxinaction.retrofit.GitHubService;
 import com.nhpatt.androidrxinaction.retrofit.Repo;
 
 import java.util.ArrayList;
 import java.util.List;
 
-import retrofit.GsonConverterFactory;
-import retrofit.Retrofit;
-import retrofit.RxJavaCallAdapterFactory;
+import rx.Observable;
 import rx.android.schedulers.AndroidSchedulers;
 import rx.schedulers.Schedulers;
 
@@ -33,22 +30,16 @@ protected void onCreate(Bundle savedInstanceState) {
 		recyclerView.setAdapter(adapter);
 		recyclerView.setLayoutManager(new LinearLayoutManager(this));
 
-		Retrofit retrofit = new Retrofit.Builder()
-			.baseUrl("https://api.github.com")
-			.addConverterFactory(GsonConverterFactory.create())
-			.addCallAdapterFactory(RxJavaCallAdapterFactory.create())
-			.build();
-		GitHubService service = retrofit.create(GitHubService.class);
-
-		service.listRepos("nhpatt")
-			.subscribeOn(Schedulers.io())
-			.observeOn(AndroidSchedulers.mainThread())
-			.subscribe(newRepos -> {
-				repos.addAll(newRepos);
-				adapter.notifyDataSetChanged();
-			});
+		github.subscribe(newRepos -> {
+			repos.addAll(newRepos);
+			adapter.notifyDataSetChanged();
+		});
 	}
 
+	static Observable<List<Repo>> github = RetrofitService.getGithub().listRepos("nhpatt")
+		.subscribeOn(Schedulers.io())
+		.observeOn(AndroidSchedulers.mainThread()).cache();
+
 	private RepositoryAdapter adapter;
 	private List<Repo> repos = new ArrayList<>();
 }

AndroidRxInAction/app/src/main/java/com/nhpatt/androidrxinaction/RetrofitService.java

@@ -0,0 +1,21 @@
+package com.nhpatt.androidrxinaction;
+
+import com.nhpatt.androidrxinaction.retrofit.GitHubService;
+
+import retrofit.GsonConverterFactory;
+import retrofit.Retrofit;
+import retrofit.RxJavaCallAdapterFactory;
+
+/**
+ * @author Javier Gamarra
+ */
+public class RetrofitService {
+	public static GitHubService getGithub() {
+		Retrofit retrofit = new Retrofit.Builder()
+			.baseUrl("https://api.github.com")
+			.addConverterFactory(GsonConverterFactory.create())
+			.addCallAdapterFactory(RxJavaCallAdapterFactory.create())
+			.build();
+		return retrofit.create(GitHubService.class);
+	}
+}