Android From The Trenches

These slides are for the talk "Android From the Trenches: Lessons learned from having two apps in the top 100 on Google Play for 3 years". You can watch a recording of this talk here: http://vimeo.com/92773940

Transcript

1. Android From The Trenches Lessons learned from having two apps in the top free category on Google play for over 3 years.
2. @donnfelker donnfelker.com
4. Two Apps In The Top 100
6. What happens when your app gets into the top free category on Google Play?
7. Quite a few things ...
8. Here’s what should happen.
9. Excitement!
10. Joy!
11. Got Monetization?
12. Then let it rain.
15. Kinda. Sometimes. Maybe Not.
16. Here’s what really happens.
17. Excitement!
18. Joy!
21. BUT THEN ...
22. All Hell Breaks Loose
23. Tons of Email Complaints, Crashes, Support Emails, Oh My!
24. What are these crashes? Huh? These never happened in dev. java.io.IOException: Attempted read from closed stream. com.android.music.sync.common.SoftSyncException: java.io.IOException: Attempted read from closed stream. at com.android.music.sync.google.MusicSyncAdapter.getChangesFromServerAsDom(MusicSyncAdapter.java:545) at com.android.music.sync.google.MusicSyncAdapter.fetchDataFromServer(MusicSyncAdapter.java:488) at com.android.music.sync.common.AbstractSyncAdapter.download(AbstractSyncAdapter.java:417) at com.android.music.sync.common.AbstractSyncAdapter.innerPerformSync(AbstractSyncAdapter.java:313) at com.android.music.sync.common.AbstractSyncAdapter.onPerformLoggedSync(AbstractSyncAdapter.java:243) at com.google.android.common.LoggingThreadedSyncAdapter.onPerformSync(LoggingThreadedSyncAdapter.java:33) at android.content.AbstractThreadedSyncAdapter$SyncThread.run(AbstractThreadedSyncAdapter.java:164) Caused by: java.io.IOException: Attempted read from closed stream. at org.apache.http.impl.io.ChunkedInputStream.read(ChunkedInputStream.java:148) at org.apache.http.conn.EofSensorInputStream.read(EofSensorInputStream.java:159) at java.util.zip.GZIPInputStream.readFully(GZIPInputStream.java:212) at java.util.zip.GZIPInputStream.<init>(GZIPInputStream.java:81) at java.util.zip.GZIPInputStream.<init>(GZIPInputStream.java:64) at android.net.http.AndroidHttpClient.getUngzippedContent(AndroidHttpClient.java:218) at com.android.music.sync.api.MusicApiClientImpl.createAndExecuteMethod(MusicApiClientImpl.java:312) at com.android.music.sync.api.MusicApiClientImpl.getItems(MusicApiClientImpl.java:588) at com.android.music.sync.api.MusicApiClientImpl.getTracks(MusicApiClientImpl.java:638) at com.android.music.sync.google.MusicSyncAdapter.getChangesFromServerAsDom(MusicSyncAdapter.java:512) ... 6 more
25. How to mitigate? Be proactive.
26. Unit Testing With JUNit, Robolectric & Mockito
27. Whoa Whoa Whoa I didnt say it was perfect
28. Example @RunWith(RobolectricTestRunner.class) public class SomeValueServiceImplTest { UserValueService uvs; UserService user; @Before public void setup() { user = mock(UserService.class); // An interface when(user.getGoals()).thenReturn(mock(UserGoals.class)); // Mock another interface uvs = new UserValueService(user); } @Test public void shouldBeAbleToGetBasicWeightHeightInfo() { when(user.getGoals().getHeight()).thenReturn(1223.0012f); when(user.getGoals().getWeight()).thenReturn("1,223g"); assertThat(uvs.getHeightGoal()).isEqualTo(1223.0012f); assertThat(uvs.getWeightGoal()).isEqualTo("1,223g"); } }
29. What Is this? assertThat(something) .isEqualTo(someOtherValue); Fest for Assertions & Fest For Android More Info: github.com/square/fest-android
30. Espresso Googles Testing tools for Android
31. Click on a spinner to open the item selection onView(withId(R.id.spinner_simple)).perform(click()); Click on the item 'Americano' onData(allOf(is(instanceOf(String.class)), is("Americano"))) .perform(click()); Verify that the TextView contains the String "Americano" onView(withId(R.id.spinnertext_simple)) .check(matches(withText(containsString("Americano"))));
32. Automate It
33. ! For Android Run Monkey against your App & Devices
34. adb -d shell monkey -p com.instagram.android -v 2000
36. Automated Acceptance Testing
37. I GOT 99 Devices and the problem is every single one
38. Testing on Multiple Devices Sucks
39. You Know Your Android Dev If your Desk Looks Like This
40. Device Lab devicelab.vanamco.com
41. Device Lab Yeah buddy
42. Device Lab Makes it Better But Testing on Multiple Devices Still Sucks
43. ADB and Spoon To The Rescue
44. Automated Distributed Instrumentation Testing
47. Cant Catch Everything Even Parachutes Have Holes
48. This Still Happens
50. Log uncaught & caught exceptions
54. What about development vs production crashes and getting them confused?
55. Use build variants in gradle
56. build.gradle buildTypes { debug { packageNameSuffix '.debug' } release { proguardFile plugin.getDefaultDexGuardFile('dexguard-release.pro') proguardFile 'dexguard-project.txt' } }
58. NO This was not a commercial or Ad for Crashlytics
59. Lesson Watch Your Crashes
60. In App Monitoring Made Easy
62. Tons of Email
63. Managing Email Load
64. Case Management Auto Assignment Email Workflow and more
67. TOOLS ZenDesk Desk.com Freshdesk UserVoice ...
68. Defensive Coding
69. Trying To Prevent
70. Null Pointer Exception AKA - NPE
71. NPE is your new BFF
72. What Shouldn't be null, will be. Thanks, Murph
73. SIMPLE EXAMPLE @Override public void onListItemClick(final ListView l, final View v, final int position, final long id) { super.onListItemClick(l, v, position, id); Toast.makeText(getActivity(), "Seems Legit!", Toast.LENGTH_SHORT).show(); } Seems Legit?
74. PFFT, I WISH
75. In Fragments We Have getActivity() Make sure you always assume its null
76. Easy to fix NPE crashes occur in Every Production Android Application
77. Lesson Always Check For Null Because at scale, it will be null Even when it should NEVER be null
78. Software Patterns Keeping you sane and healthy
79. Boss Man Says The app has to have the feature this release. I know you just heard about it and we're shipping this afternoon.
80. Making a quick & easy update Done! Commit!
82. Boss Man: Happy Your Teammates though?
83. Seriously?
84. Spaghetti Mmmmmmmm tasty
85. Why?
86. A house built upon a cardboard foundation is bound to eventually fall
87. App Architecture Matters
88. Software Patterns
89. Dependency Injection
90. Break Dependencies
92. Use Dagger
93. Compile Time Code Generation Limited Reflection
94. Using Dagger
95. Android Field Injection
96. Example Android Injection From Android Bootstrap public class NewsListFragment extends ItemListFragment<News> { @Inject protected BootstrapServiceProvider serviceProvider; @Inject protected LogoutService logoutService; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); Injector.inject(this); } }
97. POJO Constructor Injection GOOD
98. Example Pojo CTOR Injection From Android Bootstrap public class LogoutService { protected final Context context; protected final AccountManager accountManager; @Inject public LogoutService(final Context context, final AccountManager accountManager) { this.context = context; this.accountManager = accountManager; } }
99. Start This Today Instant Reward Flexibiity, composition, testing
100. Dagger Deep Dive https://speakerdeck.com/jakewharton/android-apps-with-dagger
101. How Do You Perform In App Communication?
102. I Sure hope its not statics
103. Pub Sub
104. For Goodness Sake Use an Event Bus
108. Easily communicate inside of an app Can over complicate the app though Tooling Helps
109. Popular Frameworks Otto Green Robot Event Bus RxJava
110. Well This Looks Like Fun 04-19 10:15:14.164 464-477/system_process D/BluetoothManagerService
     Stored bluetooth Name=,Address=22:22:67:56:65:B2 04-19 10:15:14.164 464-477/system_process I/InputManager
     Starting input manager 04-19 10:15:14.164 464-477/system_process I/SystemServer
     Bluetooth Manager Service 04-19 10:15:14.172 464-477/system_process I/SystemServer
     Input Method Service 04-19 10:15:14.172 464-477/system_process W/InputMethodManagerService
     Couldnt create dir.: /data/system/inputmethod 04-19 10:15:14.184 464-477/system_process W/ResourceType
     Failure getting entry for 0x7f060000 (t=5 e=0) in package 0 (error -75) 04-19 10:15:14.188 464-477/system_process E/Trace
     error opening trace file: No such file or directory (2) 04-19 10:15:14.188 464-477/system_process I/SystemServer
     Accessibility Manager 04-19 10:15:14.192 484-486/? D/SurfaceFlinger
     setOrientation, mFbdev=0xb8969e90, mFbDev->setOrientation=0xb6774e20, orientation=0 04-19 10:15:14.192 484-486/? I/gralloc_vbox86
     setOrientation: orientation=0 04-19 10:15:14.192 464-477/system_process I/SystemServer
     Mount Servic 04-19 10:15:14.196 485-485/? E/WVMExtractor
     Failed to open libwvm.so 04-19 10:15:14.196 464-477/system_process I/SystemServer
     LockSettingsService 04-19 10:15:14.196 464-477/system_process I/SystemServer
     Device Policy 04-19 10:15:14.196 464-477/system_process I/SystemServer
     Status Bar 04-19 10:15:14.196 464-477/system_process I/SystemServer
     Clipboard Service 04-19 10:15:14.196 464-477/system_process I/SystemServer
     NetworkManagement Service 04-19 10:15:14.196 464-477/system_process I/SystemServer
     Text Service Manager Service 04-19 10:15:14.204 464-477/system_process I/SystemServer
     NetworkStats Service 04-19 10:15:14.204 464-477/system_process I/SystemServer
     NetworkPolicy Service 04-19 10:15:14.208 464-524/system_process E/EventHub
     could not get driver version for /dev/input/mouse3, Not a typewriter 04-19 10:15:14.208 464-537/system_process I/PackageManager
     No secure containers on sdcard 04-19 10:15:14.208 464-537/system_process E/MountService
     Error processing initial volume state java.lang.NullPointerException at com.android.server.MountService.updatePublicVolumeState(MountService.java:630) at com.android.server.MountService.access$1400(MountService.java:103) at com.android.server.MountService$3.run(MountService.java:723) 04-19 10:15:14.208 464-477/system_process I/SystemServer
     Wi-Fi P2pService
111. Android Logs Are Terrible
112. Log.wtf No, seriously, this really exists in Android
113. Yup, Here It Is
114. But Really, Here's the Issue Log.e(tag, ...) Log.d(tag, ...) Log.i(tag, ...) Log.v(tag, ...)
115. I Like Line #s
116. Like This 04-19 10:21:13.527 1152-1152/ com.myfitnesspal.android D/ COM.MYFITNESSPAL.ANDROID/ AbstractNavigationHelper.java:370
     MFP main starting activity normally: Intent { act=android.intent.action.MAIN flg=0x16000000 cmp=com.myfitnesspal.android/ com.myfitnesspal.activity.Welcome2 }
117. The Ln Logger From RoboGuice/ Android Bootstrap
118. Forget the tags ! Ln.d("Hi") Ln.e(err, "Oh No!") Ln.i("Yo") Ln.v("Foo")
119. Ln.java Provides » File Names » Line Numbers » Package Name » Default Verbose logging for debug builds » Built in String formatting
120. Hugo Annotation-Triggered method call logging for your debug builds @DebugLog public String getName(String first, String last) { SystemClock.sleep(15); // Don't ever really do this! return first + " " + last; } Result D/Example: ⇢ getName(first="Bill", last="Cosby") D/Example: ⇠ getName [16ms] = "Bill Cosby"
121. Hugo https://github.com/JakeWharton/hugo
122. Deep Links
123. Deep Links Built Properly Open up Business opportunities and growth
124. What is a Deep Link? A URI your app intercepts and responds to I'm sure you've seen this happen with Twitter, YouTube, GooglePlus, Groupon and more
125. What does one look like? URL BASED http://www.donnfelker.com/some/path CUSTOM donnfelker://path/to/something
126. Defined in the AndroidManifest.xml <activity android:name="com.donnfelker.activity.DeepLinkRouterActivity" android:noHistory="true"> <intent-filter> <action android:name="android.intent.action.VIEW"/> <category android:name="android.intent.category.DEFAULT"/> <category android:name="android.intent.category.BROWSABLE"/> <data android:scheme="donnfelker"/> <data android:host="www.donnfelker.com" android:scheme="http" path="..."/> </intent-filter> </activity>
127. Deep Links Drive Engagement
128. Lets Talk About Fragments For a Minute
129. FRAGMENTS You need them, even if you think you dont.
130. Fragments are Good For » Responsive Layout » Screen and UX Composition » Hosting Fragments in Fragments » View Pagers » Sliding Drawer/etc
131. Start with Fragments or Migrate Now. Waiting until later is expensive
132. Do you even Build, Bro?
133. Continuous Integration
134. A core component For any team
135. Options » Jenkins » TeamCity » Travis » and a bunch more ...
136. Most Common Jenkins In House Travis Open Source
137. What gets Measured Gets Managed
138. Analytics & A/B Testing
139. Google Analytics Localytics MixPanel Custom
140. A/B Testing on Mobile?
141. Very Similar to Other A/B Test Frameworks { "abtests": [ { name: "201404-loginButtonColor", variants : [ { name: "orange", data: { color: "#FF9900" } }, { name: "yellow", data: { color: "#FEFEDF" } } ] } ] }
142. Yeah, its custom
143. Commercial Solutions - Apptimize.com - Arise.io - LeanPlum.com - AppIterate.com - SplitForce.com - Vessel - and more ...
144. Community
145. Embrace Open Source
146. Libraries - Dagger - Otto - Picasso - OkHttp - Retrofit - Spoon - Http-Request - RxJava - Gson - Jackson - Guava - Butterknife - Hugo
147. Libraries Continued - Timber - Madge - Scapel - StaggeredGrid
148. Bootstrap An App & Learning
149. Three Great Options Android Bootstrap Android Kickstartr Jake Wharton's u2020
150. Android Bootstrap
151. Android Kickstartr
152. Jake Wharton's u2020
153. Read Great Code One of the best ways to learn
154. Thats a Wrap
155. Lessons Learned
156. 1. Prepare for Things to break
157. 2. Prepare to Support Your Customers
158. 3. Remind yourself to Stay Foolish and Stay Hungry
159. Thank You Reach me at @donnfelker