Android builds with Gradle + REST security with Retrofit

Retrofit, Android, Gradle, AsyncTask, OAuth, OAuth2, Token

Transcript

1. 1. Building with Gradle 2. Rest & Security 3. Tips & Tricks Email: jo.somers@cozmos.be Twitter: @josomers LinkedIn: linkedin.com/in/josomers
2. 25 years old Graduated in 2011 Applied Computer Sciences: Multimedia Strong interest in front-end development @josomers
3. Android SDK / Gradle / Android Testing Dependency Injection / Git / Scrum Continuous Integration / ... @josomers 4 years of experience Android consultant at Cozmos
6. Our team What we do Our work
7. OUR
 TEAM
8. Joris Schutijzer Android Developer Wim Maesschalck IOS & Web Developer Alejandro Padovan IOS Developer Jo Somers Android Developer Bart De Tandt Managing Partner Sven Beeckman IOS Developer & UI Designer Peter Menten Android & Back-end Developer Mark Meeus Windows 8 Developer Klaas Rokbroek Android Developer Stefan Van De Poel Business Developer
9. Kris Weytjens IOS Developer Yannick Van Godtsenhoven Android Developer Nick Verbiest Android & Windows-phone Developer Michiel Gellynck Hybrid App Developer Bruno Van Thournout Xamarin Developer Jorge De Corte Android & IOS Developer Joris Missiaen Android Developer Bart Van Hecke Graphic & UX Designer Bart Matthys IOS & Android Developer Dwayne Coussement IOS Developer
10. Native Development
11. IOS Android Microsoft
12. Multi-platform?
13. HTML 5 Xamarin Angular JS
14. OUR
 WORK
15. Let’s talk about Android.
21. Let’s start with Android development!
24. Android Studio d.android.com Registration for only 25$ Find all the (design) guidelines
29. Build and Setup
30. • Code and resources reuse • Application variants; multi-apk distribution or different flavors • Make it easy to configure, extend and customize the build process • Good IDE integration Why a build system?
31. Gradle —> build.gradle ./gradlew clean build Maven —> pom.xml
32. apply plugin: 'com.android.application'
 
 android {
 compileSdkVersion 22
 buildToolsVersion "21.1.1"
 
 defaultConfig {
 applicationId "be.cozmos.kdg.gradleapplication"
 minSdkVersion 21
 targetSdkVersion 22
 versionCode 1
 versionName "1.0"
 }
 buildTypes {
 release {
 minifyEnabled false
 proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
 }
 }
 }
 
 dependencies {
 compile fileTree(dir: 'libs', include: ['*.jar'])
 }
33. // Top-level build file where you can add configuration options common to all sub-projects/modules.
 
 buildscript {
 repositories {
 jcenter()
 }
 dependencies {
 classpath 'com.android.tools.build:gradle:1.0.1'
 
 // NOTE: Do not place your application dependencies here; they belong
 // in the individual module build.gradle files
 }
 }
 
 allprojects {
 repositories {
 jcenter()
 }
 }
34. • Each build type triggers a new .apk • Different configuration for the same application. • Default, always present, but not always visible: release + debug AppDebug AppRelease Build types?
35. • Customised version of the application • Very minimum difference between apps AppAmsterdamDebug AppAmsterdamRelease AppParisDebug AppParisRelease Product flavors?
39. Another example
40. ASYNC.
41. AsyncTask<Void, Void, Void> { ... } 1) onPreExecute() 2) doInBackground (Params ...) 3) onProgressUpdate(Progress ...) 4) onPostExecute(Result)
42. new DownloadFilesTask().execute(url1, url2, url3); private class DownloadFilesTask extends AsyncTask<URL, Integer, Long> { protected Long doInBackground(URL... urls) { int count = urls.length; long totalSize = 0; for (int i = 0; i < count; i++) { totalSize += Downloader.downloadFile(urls[i]); publishProgress((int) ((i / (float) count) * 100)); // Escape early if cancel() is called if (isCancelled()) break; } return totalSize; } protected void onProgressUpdate(Integer... progress) { setProgressPercent(progress[0]); } protected void onPostExecute(Long result) { showDialog("Downloaded " + result + " bytes"); } }
43. HTTP COMM.
46. HttpURLConnection —> BufferedInputStream —> Read as String —> Parse string w/ Gson to desired Object http://developer.android.com/reference/java/net/HttpURLConnection.html HttpURLConnection connection = null;
 try {
 URL url = new URL(BASE_URL + context.getString(R.string.city_id) + ".json");
 
 connection = (HttpURLConnection) url.openConnection();
 connection.setConnectTimeout(1000);
 connection.setReadTimeout(5000);
 
 return new Gson().fromJson(IOUtils.toString(connection.getInputStream()),
 new TypeToken<List<Station>>() {
 }.getType());
 } catch (IOException e) {
 return null;
 } finally {
 if (connection != null) {
 connection.disconnect();
 }
 }
47. <?xml version="1.0" encoding="utf-8"?>
 <manifest xmlns:android="http://schemas.android.com/apk/res/android"
 package="be.cozmos.kdg.gradleapplication" >
 
 <uses-permission android:name="android.permission.INTERNET" />
 
 <application
 android:allowBackup="true"
 android:icon="@mipmap/ic_launcher"
 android:label="@string/app_name"
 android:theme="@style/AppTheme" >
 <activity
 android:name="be.cities.activities.MainActivity"
 android:label="@string/app_name" >
 <intent-filter>
 <action android:name="android.intent.action.MAIN" />
 
 <category android:name="android.intent.category.LAUNCHER" />
 </intent-filter>
 </activity>
 </application>
 
 </manifest>

50. compile 'com.squareup.retrofit:retrofit:1.9.0'
51. Application w/ RestAdapter Builder Add parser —>Gson (or Jackson) —> parse string into object —> parse object to string GET a list of stations Define Retrofit interface for RestAdapter
52. public interface CityRetrofitService {
 
 @GET("/{city_id}.json")
 void getStations(@Path("city_id") String cityId, Callback<List<Station>> callback);
 
 }

53. final Callback<List<Station>> callback = new Callback<List<Station>>() {
 @Override
 public void success(List<Station> stations, Response response) {
 cityInfoTextView.setText("### " + stations.size() + " ###");
 }
 
 @Override
 public void failure(RetrofitError error) {
 Toast.makeText(getApplicationContext(), "Oops, something went wrong.",
 Toast.LENGTH_SHORT).show();
 }
 };
 
 CityApplication.getCityRetrofitService()
 .getStations(getString(R.string.city_id), callback);
55. REST Security
58. Basic Authentication Authorization: Basic QWxhZGRpbjpvcGVuIHNlc2FtZQ==
59. What is OAuth? OAuth is an authentication protocol that allows users to approve application to act on their behalf without sharing their password.
61. What is OAuth 2.0? The OAuth 2.0 authorization framework enables a third- party application to obtain limited access to an HTTP service, either on behalf of a resource owner by orchestrating an approval interaction between the resource owner and the HTTP service, or by allowing the third-party application to obtain access on its own behalf.
63. OAuth 2.0 > OAuth
65. Simple TOKEN based authentication
66. public interface CityRetrofitService {
 
 @GET("/{city_id}.json")
 void getStations(@Header("Authorization") String token,
 @Path("city_id") String cityId,
 Callback<List<Station>> callback);
 
 }

67. final Gson gson = new GsonBuilder().create();
 
 final RequestInterceptor requestInterceptor = new RequestInterceptor() {
 @Override
 public void intercept(RequestFacade request) {
 if (isUserLoggedIn()) {
 request.addHeader("Authorization", getToken());
 }
 }
 };
 
 return new RestAdapter.Builder()
 .setConverter(new GsonConverter(gson))
 .setEndpoint("http://api.citybik.es")
 .setRequestInterceptor(requestInterceptor)
 .build()
 .create(CityRetrofitService.class);
69. SharedPreferences sharedpreferences = getSharedPreferences("MyPreferences", Context.MODE_PRIVATE);
 sharedpreferences.edit().putString("Token", "123456").commit();
 
 String token = sharedpreferences.getString("Token", null);
70. http://futurestud.io/blog/retrofit-series-round-up/
71. Tips & Tricks
72. Setup an emulator?
73. Setup an emulator? Setup GenyMotion!
75. Libraries / Frameworks / Inspiration Dagger Picasso Otto Crouton StickyListHeaders Butterknife ViewPagerIndicator
76. http://developer.android.com/tools/testing/testing_android.html … https://code.google.com/p/android-test-kit/wiki/Espresso http://robolectric.org/ Android Testing
77. How to track errors/crashes?
80. How to track analytics/usage?
81. How to track analytics/usage? @Override public void onStart() { super.onStart(); EasyTracker.getInstance().activityStart(this); } @Override public void onStop() { super.onStop(); EasyTracker.getInstance().activityStop(this); }
83. minSdkVersion=”15” targetSdkVersion=”21” = Ice Cream Sandwich/Jelly Bean/KitKat/Lollopop
84. Toolbar / Navigation Drawer
 (see Android documentation)
85. FYI Tap 7 times on the build number
 to enable developer mode
87. • Follow Android developers on G+ • Read articles about Android • Resources every Android developer
 must know http://cl.ly/1Z3z0G440H3E
88. - Drawables : hdpi/xxhdpi/xdpi/... - Styles for Actionbar, widgets… - Holo styles & colors - App Launcher Icons - Generic icons Android Asset Studio
89. Questions ?
90. Access code examples here: https://bitbucket.org/josomers