Android Global Error Handling and Reporting Activity

Question

I there any way to register a global error handler that will prevent application from crashing? Crashing reporting is described here: How do I obtain crash-data from my Android application?. One thought I had was to extend these solutions to take in the application context so a redirect to a particular reporting activity could be made? But not sure if the application context is valid at this point once there is a crash to report?

But how can you redirect user to a global error message Activity when there is a crash? Is there some high level way to register an error handler that will catch all errors and prevent a crash? Is there a way to register such a handler so that it prevents or survives a crash and then redirects the user to a particular activity which will show the error message in question?

Here is my modification to error handler:

1) Just pass applicationContext into constructor as ctx

2) add reportError(stackTrace) method to transfer control to error message page

private void reportError(String stackTrace){
        Intent i = new Intent(ctx, DisplayErrorActivity.class);
        i.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
        i.setAction("DISPLAY_ERROR_ACTIVITY");
        Bundle b = new Bundle();
        b.putString("STACKTRACE", stackTrace);

        i.putExtras(b); 
        try{
             Log.d("MyErrorHandler","reportError ctx="+ctx);
             ctx.startActivity(i); 
        } catch (Exception e) {
             Exception ex = e;
             e.printStackTrace();
        }

    }

And call reportError below:

public void uncaughtException(Thread t, Throwable e) {
        Log.d("MyUncoughtExceptionHandler", "uncoughtException ctx="+ctx);
        String timestamp=getDateTime();
        final Writer result = new StringWriter();
        final PrintWriter printWriter = new PrintWriter(result);
        e.printStackTrace(printWriter);
        String stacktrace = result.toString();
        printWriter.close();
        String filename = timestamp + ".stacktrace";
        Log.d("MyexceptionHanlder","UncoughtException: "+stacktrace);
        if (localPath != null) {
            writeToFile(stacktrace, filename);
        }
        if (url != null) {
            sendToServer(stacktrace, filename);
        }
        reportError(stacktrace);
       // defaultUEH.uncaughtException(t, e);

    }

If I leave commented defaultUEH it shows usual crash dialog. Without it - blank screen. Log indicates that ErrorMessageActivity is force closed along with the process.

To test I just put divide by zero in create method of main activity right after registering the error handler with the thread. If I had a try-catch block over this it would not crash, but the global error handler does not seem to prevent crash. Checked ctx and it seems valid in a debugger.

score 6 · Answer 1 · answered Apr 21 '11 at 12:36

When implementing ACRA, I have never been able to start a new Activity after receiving an uncaught exception. It looks like the whole process is switched by the system to a special state preventing him from allowing any new resource.

The only option I have found for the moment is to send a status bar notification which is kept by the system after the application being restarted. The notification then triggers an intent for a dialog activity when the user selects it.

Alexey Yakovlev studied in much more details this issue and came to the conclusion that there could be a chance of triggering a new activity when the crash occurs on a thread which is not the UI thread. Though we did not find a simple enough workaround to start directly an activity in all cases.

I got rid of the default force close dialog by killing the process myself without invoking the orginial default uncaught exception handler.

score 3 · Answer 2 · answered Apr 21 '11 at 07:21

3

you can setUncaughtExceptionHandler for your thread.

answered Apr 21 '11 at 07:21

Vladimir Ivanov

42,730
18
77
103

yes. how do you then get to the error message activity which will say something like "See Admin Some Error Instruction" How can this handler display an error message to the user by switching to an activity? – Androider Apr 21 '11 at 07:40
Your exception handler should be aware of application context. Then using this context you can start new activity or may be(not sure) show an error dialog. – Vladimir Ivanov Apr 21 '11 at 07:44
Lets say in some activity you do a divide by zero? Will the app still crash if you have UncoughtExceptionHandler set? – Androider Apr 21 '11 at 07:52
I think yes, but haven't checked it by myself. Nothing stops you from a try. Please, post here if it was successful. – Vladimir Ivanov Apr 21 '11 at 07:52
Just checked and a devide by zero is a crash. Just like null pointer exception. Whole app crashes so there is really no effect to the app.context switch activity request. – Androider Apr 21 '11 at 08:10
No I am going to try wrapping this in try catch and see if that stops the crash. – Androider Apr 21 '11 at 08:10
Yes Try/Catch block works. It stops the crash of the app. So how do you use setUncoughtExceptionHandler to prevent the crash at global leve? Thats what a global error handler is supposed to do? – Androider Apr 21 '11 at 08:13
Found this question : http://stackoverflow.com/questions/2764394/ideal-way-to-set-global-uncaught-exception-handler-in-android, see if it can help... – Vladimir Ivanov Apr 21 '11 at 08:13
What I really want is a global error handler where if I miss a try catch block inside an activity I can catch it outside without a crash of the application. Just switch pages, maybe activity gets shutdown ok, but I should be able to switch to another activity and show the error not have the whole app stop/shutdown. – Androider Apr 21 '11 at 08:57

Android Global Error Handling and Reporting Activity

2 Answers2

Linked