1. Crashing inCrashing in

2. About /me
• Tam HANNA
– CEO, Tamoggemon
Ltd.
– Director, Tamoggemon
Holding k.s.
– Runs web sites about
mobile computing
– Writes scientific books

3. About /girly
• Annette BOSBACH
– Clerk to the
coordinating office,
Tamoggemon Holding
k.s.
– First GottaTxt fan

4. Overview
• The schedule
• Why track crashes
• Basic methods
• ACRA

5. Source code
• JAVA Source code is available
– Via Twitter
• Our IP: free to use
– Too low to qualify for protection
– Plus, you have to listen to us so 

6. The schedule

7. Crash first, Qt
second• 60% / 40%
– More about Qt: at our booth
• Please tweet about us

8. The @tamhanna show is co
GottaTxt is the best app at
#droidconnl
After listening to
@tamhanna, my app doesn‘t
crash anymore!!!
@tamhanna threw chocolate on
my head. Ouch! #droidconnl

9. Why trackWhy track

10. Market is crowded
• Bad ratings kill an application
• BUT: responding to feedback helps
– „The developer responds to ME!!!“
– I am important
– Ego issues => superhappy customer

11. Why track crashes?
• Isn‘t it better not to crash?
– Matthew A Brenner, UnME2
• Yes, but
– Ever-increasing number of LOC
– Fragmentation (to see /me mention that )
– Margin pressure
• TU144 / Concorde problem

12. Users are stupid
• What OS version do you use?
– Common question for developers
– Perceived as denigration by some users
• Send me a file from the file system!
– Common question for developers
– But for developer‘s wife or husband?

13. Crash vs stat
tracking• Stat tracking
– Which flows are used
– Entry/Exit path analysis
– e.g. Google Analytics
• Crash tracking
– What causes crashes
– Where do users „die“

14. And there‘s more
• Track „points of pain“ for users
– Rejection of user input
– Games: user death
• Fix them in the next release
– First 2min with application are critical

15. Private debuggerPrivate debugger
Picture: Wikimedia Commons / fluteflute

16. What‘s that
• Special mode of operation
– Allows developer access to internals
– ON the users phone
• Can be accessed via secret key
– Must be easy to enter, difficult to guess
– Prevent users from entering it by mistake
• Customer provides info to developer

17. How to implement
• By foot
• No ready made libraries available

18. Example
• GottaTxt
1. Open Thread
2. Enter „Secret Code“
3. Enter commands
4. Give response

19. Try it at our booth
FREE VODKAFREE VODKA
INCLUDED!!!INCLUDED!!!

20. Basic crashBasic crash
handlinghandling
Wikimedia Commons / David Monack

21. Really easy way
• Thread.setDefaultExceptionHandler()
• Write to file, then die
• Tell user to email file
– Can usually be accomplished

22. Problems
• IO is buffered
• Thread terminates before data written
• Data lost
• !!!Occurs rarely!!!
– Never saw it on Android

23. Non-working
solution• StackOverflow user gupta
• Fire intent from exception handler
• Hope for it to arrive

24. Non-working
solution - II• Doesn‘t work in practice
• Intent never arrives at application

25. Workable solution
• Completely override crash handling
– No Android Crash message shown
• Re-invoke application
• Example a360crash1

26. public ExceptionTrap(Context _context, String _filePath)
{
myContext=_context;
myFilePath=_filePath;
myHandler=Thread.getDefaultUncaughtExceptionHandler();
}

27. @Override
public void uncaughtException(Thread _t, Throwable _a)
{
try
{
StringWriter s=new StringWriter();
_a.printStackTrace(new PrintWriter(s));
Intent launchIntent=new Intent(ErrorReporter.INTENTSTRING);
launchIntent.putExtra("StackTrace", s.toString());
launchIntent.putExtra("FilePath", myFilePath);
PendingIntent pIntent=PendingIntent.getService(myContext, 0,
launchIntent, launchIntent.getFlags());
AlarmManager mgr = (AlarmManager)
myContext.getSystemService(Context.ALARM_SERVICE);
mgr.set(AlarmManager.RTC, System.currentTimeMillis() + 2000, pIntent);
System.exit(2);

28. public class ErrorReporter extends IntentService
{
public static final String INTENTSTRING
="com.tamoggemon.a360crash1.intent.CALLERRORREPORTER";
public ErrorReporter()
{
super("TAG");
}
@Override
public void onCreate()
{
super.onCreate();
}

29. protected void onHandleIntent(Intent intent)
{//Newline, etc removed
try
{
boolean newFile=false;
File writeFile=new File(intent.getStringExtra("FilePath"));
if(writeFile.exists()==false)
{
newFile=true;
writeFile.createNewFile();
}
BufferedWriter buf = new BufferedWriter(new FileWriter(writeFile,
true));
if(newFile)
{
buf.append(android.os.Build.MODEL);
buf.append(android.os.Build.VERSION.RELEASE);
}
buf.append("-------------------CRASH-------------------")
buf.append(intent.getStringExtra("StackTrace"));

30. public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
myTrap=new ExceptionTrap(this, "/sdcard/A360Crash.log");
Thread.setDefaultUncaughtExceptionHandler(myTrap);
setContentView(R.layout.main);
findViewById(R.id.button1).setOnClickListener(this);
}
@Override
public void onClick(View v)
{
throw new RuntimeException("Fehler erfolgreich ausgelöst!");
}

31. <service android:name=".ErrorReporter">
<intent-filter >
<action
android:name="com.tamoggemon.a360crash1.intent.CALLERROR
REPORTER" />
</intent-filter>
</service>

32. ACRAACRAWikimedia Commons / gerol

33. What is ACRA
• Android Crash Report for Android
• Very flexible library
• Can dump crash data to Google Docs

34. Set up online
• Google Account needed
• Create new form via SpreadSheet
• Export it to get FormKey

35. Integrate into app
@ReportsCrashes(formKey =
"dExKcElJWjVaUkpMem9WOWg3VE80SlE6MQ")
public class MyApplication extends Application
{
@Override
public void onCreate()
{
ACRA.init(this);
super.onCreate();
}
}

36. Custom data
• if(v==cmdStoreA)
• {
•
ErrorReporter.getInstance().putCustomData("myVariable
", "A");
• }
• if(v==cmdStoreB)
• {
•
ErrorReporter.getInstance().putCustomData("myVariable
", "B");
• }

37. Enable / Disable
• if(v==cmdEnable)
• {
• SharedPreferences
aPrefs=ACRA.getACRASharedPreferences();
• Editor anEditor=aPrefs.edit();
• anEditor.putBoolean("acra.enable", true);
• anEditor.commit();
• }
• if(v==cmdDisable)
• {
• SharedPreferences
aPrefs=ACRA.getACRASharedPreferences();
• Editor anEditor=aPrefs.edit();
• anEditor.putBoolean("acra.enable", false);
• anEditor.commit();
• }

38. Further Options
• ACRA does a LOT
– Interact with users
– Custom databases
• https://github.com/ACRA/acra/wiki/AdvancedUsage

39. OOP FTW

40. Problem of all
solutions• Integration requires manual work
– Find all classes
– Integrate logging code
• Better solution: „stub objects“

42. How to implement it
• By foot
• Loads of leeway for developers
– Abstract actual logging?

43. Example
public abstract class TMGNActivity extends Activity
{
@Override
public final void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
logThis("Creating Activity");
logThis(getClass().getName());
tmgnOnCreate(savedInstanceState);
}
public abstract void tmgnOnCreate(Bundle savedInstanceState);

44. Other vendors

45. Google Play Crash
tracking• Google Play provides crash tracking
– Rudimentary, can‘t add own data
• Better than nothing
– Check often
– Log-in freq. could (!!!) be used for ranking

46. Crash Trackers
• BugSense
– Specialized service
• Flurry
– Afterthought for premium analytics
• Yours?
– Tell us in Q&A

47. ConclusionConclusion

48. Crashes will happen
• Today‘s mobile apps are
– Highly complex
– Underfunded (thanks, Apple!)
• Even the OS crashes sometimes
• Users tolerate reasonable crashingUsers tolerate reasonable crashing

49. Work-arounds are
needed• Paid users expect frequent updates
– Let them generate their wishes themselves
• Monitoring is first step to improvement
– See what users really think

50. Olympic spirit
• Important:
– TRACK CRASHES
– Perform PDCA cycle on data
• Not so important
– How to track them
– Track 100% of them

51. ?!?
tamhan@tamoggemon.com
@tamhanna