The document provides a guide for getting started with Android development, focusing on key libraries and tools such as Dagger 2 for dependency injection, RxJava for asynchronous programming, and various libraries for handling network requests and image loading. It includes code snippets demonstrating the implementation of these libraries, particularly in user authentication and data handling processes. The document emphasizes a structured approach to building applications with a focus on best practices in Android development.

1. Android Getting Started
The UPTech way

2. What’s on the list?
Basic Libraries
Dependency Injection with Dagger 2
RxAndroid
Custom Views FTW
The Future: Kotlin

3. Basic Libraries
Butterknife
Retrolambda
REST Trio: Retrofit, OkHttp, Gson
Image Loading: Glide, Fresco
Realm

4. Dependency Injection with Dagger 2
class ApiService {
public void uploadPhoto(String user, File file) {
OkHttpClient client = new OkHttpClient();
Gson gson = new Gson();
Request request = // TODO build a post request
client.newCall(request).execute();
}
}

5. Dependency Injection with Dagger 2
class ApiService {
Gson gson = new Gson();
OkHttpClient client = new OkHttpClient()
public void uploadPhoto(String user, File file) {
Request request = // TODO build a post request
client.newCall(request).execute();
}
}

6. Dependency Injection with Dagger 2
class ApiService {
Gson gson;
OkHttpClient client;
public ApiService(OkHttpClient client, Gson gson) {
this.client = client;
this.gson = gson;
}
public void uploadPhoto(String user, File file) {
Request request = // TODO build a post request
client.newCall(request).execute();
}
}

7. Dependency Injection with Dagger 2
OkHttpClient client = new OkHttpClient();
Gson gson = new Gson();
ApiService apiService = new ApiService(client, gson);
apiService.uploadPhoto("UPTechTeam", file);

8. Dependency Injection

9. OkHttpClient client = new OkHttpClient();
Gson gson = new Gson();
ApiService apiService = new ApiService(client, gson);
RealmConfiguration config = new RealmConfiguration.Builder(context)
.deleteRealmIfMigrationNeeded()
.build();
Realm.setDefaultConfiguration(config);
Realm realm = Realm.getDefaultInstance();
Preferences preferences = new Preferences(context);
AccountManager accountManager = new AccountManager(apiService, database, preferences);
accountManager.getUser();
Dependency Injection

10. @Inject
AccountManager accountManager;
@Override
protected void onCreate(final Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
Application.appComponent().inject(this);
accountManager.getUser()
}
Dependency Injection with Dagger 2

11. api.registerWithEmail(email, password, new Callback<RegisterResponse>() {
@Override
public void onResponse(Call<RegisterResponse> call, Response<RegisterResponse> response) {
if (response.isSuccess()) {
api.getUser(response.token, new Callback<User>() {
@Override
public void onResponse(Call<User> call, Response<User> response) {
if (response.isSuccess()) {}
database.saveUser()
} else {
showError(...);
}
}
@Override
public void onFailure(Call<User> call, Throwable t) {
showError(...);
}
});
} else {
if (ErrorResponse.isAlreadyRegistered(response.getErrorBody())) {
api.login(email, password, new Callback<LoginResponse>() {
@Override
public void onResponse(Call<LoginResponse> call, Response<LoginResponse> response) {
preferences.saveToken(response);
api.getUser(response.token, new Callback<User>() {
@Override
public void onResponse(Call<User> call, Response<User> response) {
RxAndroid

12. public Observable<UserInfo> registerAndLogin(String email, String password) {
return apiService.registerWithEmail(new RegisterRequest(email, password))
.flatMap(userInfo -> apiService.signInWithEmail(new SignInRequest(email, password)))
.doOnNext(signInResponse -> preferences.saveAccessToken(signInResponse.accessToken))
.onErrorResumeNext(e -> ErrorResponse.isAlreadyRegistered(e) ? apiService.signInWithEmail(new
SignInRequest(email, password)) : errorObservable(e))
.flatMap(ignore -> getUser())
.doOnNext(user -> database.saveUser(user));
}
RxAndroid

13. >> Improving UX with RX
RxAndroid

14. >> Thanks!
UPTech