BOILING OUT BOILERPLATE

Hi, I'm Maciej

BOILERPLATE

NETWORKING

HttpURLConnection urlConnection = null;
BufferedReader reader = null;
String forecastJsonStr = null;
try {
    URL url = new URL("http://api.openweathermap.org/data/2.5/forecast
            /daily?q=94043&mode=json&units=metric&cnt=7");
    urlConnection = (HttpURLConnection) url.openConnection();
    urlConnection.setRequestMethod("GET");
    urlConnection.connect();
    InputStream inputStream = urlConnection.getInputStream();
    StringBuffer buffer = new StringBuffer();
    if (inputStream == null) {
        forecastJsonStr = null;
    }

NETWORKING

    reader = new BufferedReader(new InputStreamReader(inputStream));
    String line;
    while ((line = reader.readLine()) != null) {
        buffer.append(line + "\n");
    }
    if (buffer.length() == 0) {
        forecastJsonStr = null;
    }
    forecastJsonStr = buffer.toString();

NETWORKING

} catch (IOException e) {
    Log.e("PlaceholderFragment", "Error ", e);
    forecastJsonStr = null;
} finally{
    if (urlConnection != null) {
        urlConnection.disconnect();
    }
    if (reader != null) {
        try {
            reader.close();
        } catch (final IOException e) {
            Log.e("PlaceholderFragment", "Error closing stream", e); 

NETWORKING

JSONObject forecastJson = new JSONObject(forecastJsonStr);
JSONArray weatherArray = forecastJson.getJSONArray("list");
JSONObject dayForecast, weatherObject;
String[] resultStrs = new String[numDays];
for(int i = 0; i < weatherArray.length(); i++) {
    dayForecast = weatherArray.getJSONObject(i);
    long dateTime = dayForecast.getLong("dt");
    String day = getReadableDateString(dateTime);
    weatherObject = dayForecast.getJSONArray("weather").getJSONObject(0);
    String description = weatherObject.getString("main");
    JSONObject temperatureObject = dayForecast.getJSONObject("temp");
    double high = temperatureObject.getDouble("max");
    double low = temperatureObject.getDouble("min");

Networking

• Retrofit
• Picasso
• Universal Image Loader
  

NETWORKING

public interface WeatherApi {
    @GET("/data/2.5/forecast/daily?q=94043&mode=json&units=metric&cnt=7")
    List<WeatherResult> requestWeatherForNext7Days();
}

RestAdapter restAdapter = new RestAdapter.Builder()
        .setEndpoint("http://api.openweathermap.org")
        .build();
WeatherApi api = restAdapter.create(WeatherApi.class);
List<WeatherResult> results = api.requestWeatherForNext7Days();

LAZY, But...

Intent intent = new Intent(this, MenuItemActivity.class);
intent.putExtra(MenuItemActivity.EXTRA_PLACE, currentPlace);
intent.putExtra(MenuItemActivity.EXTRA_ITEM, selectedItem);
startActivity(intent);

LAZY, But...

MenuItemActivity.intent(this)
        .place(currentPlace)
        .item(selectedItem)
        .start();

HOW?

REFLECTION

• RoboGuice
  

ANNOTATION PROCESSING API

• Android Annotations
• ButterKnife
• Parceler / AutoParcel
  
• Icepick / Memento
  
• ...
  

BYTECODE WEAVING

• Hugo
• LogLifeCycle
  

AST TRANSFORMATIONS

• Lombok + Hrisey
• Groovy
  

MAGIC?

 public final class LoginActivity extends Activity {

    @MagicViews
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.login_activity);
        usernameField.setText(prefs.getUsername());
    }

    private void onSignInButtonClick() {
        String username = usernameField.getText().toString();
        String password = passwordField.getText().toString();
        // make API call
    }
}

TALK IS CHEAP,

SHOW ME THE CODE

Q || A

THANKS!

Now code only what is worth coding!

LINKS

• twitter: @mg6maciej
• github: mg6maciej
• simple-github-client
• Bytecode weaving
• Groovy on Android