April 2017

There were 2 posts published in April 2017 (this is page 1 of 1).

Android Zombie Processes – Is My App Still Alive?

To the eye, it may seem like your Android application is “dead” when you “kill” the app via the task manager, but you may be surprised that in many cases, the application process lives on.

Here are some ADB commands that you can diagnose and investigate what’s going on, on the device.

Determine Running Processes via ADB

All Processes

adb shell ps

Your Process

adb shell ps | grep com.mydomain.myappnamegoeshere

An Android Service registered to your application will prevent your process from being killed if it is currently running.  Therefore you need to be careful and aware that your singleton variables in your application are aware of this.  Read more about this here: Processes and Application Life Cycle.

void onTaskRemoved (Intent rootIntent)

You can leverage the Service::onTaskRemoved() method in Android to catch this “swipe” event where the user intends to “kill” your app via the task manager, even if services continue to run in the background.  This can be useful to catch this event if you want to end a user session for instance.  This can also be useful if your intention is to stop services when the user dismisses your app, as you can programatically stop the service at this point in time as well.

Note: If you have set ServiceInfo.FLAG_STOP_WITH_TASK when starting the Service, then you will not receive this callback; instead, the service will simply be stopped.

Determine TLS Version & Cipher Suite Used in OkHttp Calls

Working with SSL Handshakes is no fun (to an application developer like me), but with an OkHttp 3 Interceptor, and the nicely typed TlsVersion and CipherSuite objects, it becomes a lot less painful.

If you want to know which TLS version and Cipher Suite was ACTUALLY used for a specific request, use this OkHttp 3 Interceptor:

 

You’ll get Logcat output that looks like this:

OkHttp3-SSLHandshake: TLS: TLS_1_2, CipherSuite: TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA

With OkHttp 3, you can specify what TLS version(s) and Cipher Suite(s) you want your calls to support (But it only works on Lollipop and higher).

Check out the OkHttp 3 documentation on HTTPS for more info.

Note: You can get newer versions of TLS (Like 1.1 and 1.2) working on < Lollipop, but that has to be done outside the OkHttp 3 configuration unfortunately. See how to do that here.  Maybe this is a good reason to bump your minSdk to 21 🙂