GodBlessYou

In English | 中文

GBU is an Android library that tries to fix your app when it crashes. You will never get the hated "X has stopped" dialog.

You can download an apk of the demo project.

Table of Contents

• Gradle Dependency
• Integration
• How it works
  • Fix Activity Crash
  • Fix Service Crash
  • Fix BroadcastReceiver Crash
  • Fix Other Crash
• About Author
• LICENSE

Gradle Dependency

The Gradle Dependency is available via jCenter

Add dependencies directly

implementation 'god.bless.you:gbu:0.0.2'

Integration

Integrate with kotlin

class App : Application() {
    override fun attachBaseContext(base: Context?) {
        super.attachBaseContext(base)
        Gbu.init(this)
                .setDebug(true)
                .enableLifecycleCrash(true)
                .enableOtherCrash(false)
                .install()
    }
}

How it works

Fix Activity Crash

GBU 'fix' the crash in the Activity lifecycle by hooking ActivityThread's field mInstrumentation.

GbuInstrumentationImpl.kt

override fun callActivityOnCreate(activity: Activity?, icicle: Bundle?) {
    try {
        super.callActivityOnCreate(activity, icicle)
    } catch (e: Throwable) {
        e.printStackTrace()
    }
}

override fun callActivityOnCreate(activity: Activity?, icicle: Bundle?, persistentState: PersistableBundle?) {
    try {
        super.callActivityOnCreate(activity, icicle, persistentState)
    } catch (e: Throwable) {
        e.printStackTrace()
    }
}

override fun callActivityOnNewIntent(activity: Activity?, intent: Intent?) {
    try {
        super.callActivityOnNewIntent(activity, intent)
    } catch (e: Throwable) {
        e.printStackTrace()
    }
}

override fun callActivityOnRestart(activity: Activity?) {
    try {
        super.callActivityOnRestart(activity)
    } catch (e: Throwable) {
        e.printStackTrace()
    }
}

override fun callActivityOnStart(activity: Activity?) {
    try {
        super.callActivityOnStart(activity)
    } catch (e: Throwable) {
        e.printStackTrace()
    }
}

override fun callActivityOnResume(activity: Activity?) {
    try {
        super.callActivityOnResume(activity)
    } catch (e: Throwable) {
        e.printStackTrace()
    }
}

override fun callActivityOnPause(activity: Activity?) {
    try {
        super.callActivityOnPause(activity)
    } catch (e: Throwable) {
        e.printStackTrace()
    }
}

override fun callActivityOnStop(activity: Activity?) {
    try {
        super.callActivityOnStop(activity)
    } catch (e: Throwable) {
        e.printStackTrace()
    }
}

override fun callActivityOnDestroy(activity: Activity?) {
    try {
        super.callActivityOnDestroy(activity)
    } catch (e: Throwable) {
        e.printStackTrace()
    }
}

override fun callActivityOnPostCreate(activity: Activity?, icicle: Bundle?) {
    try {
        super.callActivityOnPostCreate(activity, icicle)
    } catch (e: Throwable) {
        e.printStackTrace()
    }
}

override fun callActivityOnPostCreate(activity: Activity?, icicle: Bundle?, persistentState: PersistableBundle?) {
    try {
        super.callActivityOnPostCreate(activity, icicle, persistentState)
    } catch (e: Throwable) {
        e.printStackTrace()
    }
}

override fun callActivityOnSaveInstanceState(activity: Activity?, outState: Bundle?) {
    try {
        super.callActivityOnSaveInstanceState(activity, outState)
    } catch (e: Throwable) {
        e.printStackTrace()
    }
}

override fun callActivityOnSaveInstanceState(activity: Activity?, outState: Bundle?, outPersistentState: PersistableBundle?) {
    try {
        super.callActivityOnSaveInstanceState(activity, outState, outPersistentState)
    } catch (e: Throwable) {
        e.printStackTrace()
    }
}

override fun callActivityOnRestoreInstanceState(activity: Activity?, savedInstanceState: Bundle?) {
    try {
        super.callActivityOnRestoreInstanceState(activity, savedInstanceState)
    } catch (e: Throwable) {
        e.printStackTrace()
    }
}

override fun callActivityOnRestoreInstanceState(activity: Activity?, savedInstanceState: Bundle?, persistentState: PersistableBundle?) {
    try {
        super.callActivityOnRestoreInstanceState(activity, savedInstanceState, persistentState)
    } catch (e: Throwable) {
        e.printStackTrace()
    }
}

Fix Service and BroadcastReceiver Crash

GBU 'fix' the crash in the Service and BroadcastReceiver lifecycle by hooking Instrumentation's method onException.

GbuInstrumentationImpl.kt

class GbuInstrumentationImpl(base: Instrumentation) : GbuInstrumentationWrapper(base) {

    /**
     * If true is returned, the system will proceed as if the exception didn't happen.
     */
    override fun onException(obj: Any?, e: Throwable?): Boolean {
        GbuActivityThread.handleException(obj)
        return true
    }
}

GbuActivityThread.kt

object GbuActivityThread {
    /**
     * Prevent incomplete lifecycle leads to anr.
     */
    fun handleException(obj: Any?) {
        if (Gbu.debug) {
            GbuLog.d(codeToString(mMsg?.what!!))
        }
        if (obj is Service) {
            when (mMsg?.what) {
                CREATE_SERVICE -> handleCreateService(obj)
                SERVICE_ARGS -> handleServiceArgs(obj)
                STOP_SERVICE -> handleStopService(obj)
                BIND_SERVICE -> handleBindService(obj)
                UNBIND_SERVICE -> handleUnbindService(obj)
            }
        } else if (obj is BroadcastReceiver) {
            GbuBroadcastReceiver.setPendingResult(obj, null)
        }
    }
}

Fix Other Crash

object Gbu {
    init {
        Handler(Looper.getMainLooper()).post {
            // Do not let the main thread exit.
            while (true) {
                try {
                    Looper.loop()
                } catch (e: Throwable) {
                    e.printStackTrace()
                }
            }
        }
        // Catch all threads crashes
        Thread.setDefaultUncaughtExceptionHandler { _: Thread, throwable: Throwable ->
            throwable.printStackTrace()
        }
    }
}

About Author

Pengfeng Wang(王鹏锋)

email: ximsfei@gmail.com

License Apache 2.0