How can I debug an app without reinstalling it? - android

I have an Android app that needs to perform a certain task one time after it's installed, and then never again. It uses SharedPreferences to record that it's performed the task successfully.
In order to test this behavior, I run the task via Android Studio on a real device, connected over USB. The problem is, every time I run the app via Android Studio, it reinstalls. As such, it seems to lose its persistent memory (SharedPreferences).
It makes sense that the app's SharedPreferences should be wiped when it's reinstalled. But how do you run an app in the Android Studio debugger without reinstalling it and wiping the persistent memory? I looked at the Android docs for running an app from Android Studio, and from the command line, but none of them seemed to offer a way to run it with a debugger connected without reinstalling.
One option I see to accomplish this would be by closing and re-launching the app from the device itself, and then attaching the debugger in Android Studio to the app's process. But this would mean the debugger misses the first few seconds or so of the process's activity. My app's task gets done in the first microseconds. I should still be able to view the logs from those first few seconds, but not to have full debugger control.
Any ideas?

if you directly run app from android studio from same machine it will not reinstall it updates the app so your sharedpreference will not wiped it remain same. For more info about sharedpreferances http://developer.android.com/reference/android/content/SharedPreferences.html
for debug from first step you can use debug option which run app directly in debug mode (shift+f9)
https://developer.android.com/tools/debugging/debugging-studio.html

Related

Android studio Instant Run restarts whole app every time

I'm running Android Studio 2.3.2, gradle:2.3.2.
Every time I click Instant Run button the whole app restarts with this message in log:
Instant Run applied code changes and restarted the app. The app was
restarted since it uses multiple processes.
However, I do not use android:process anywhere in my code.
Moreover, there are no processes in Android Device Monitor or Android Monitor except main
one.

is there a way to launch google device inspect on cordova run app on device function

I am debugging app with cordova and I have always wondered if there was a way to launch googles device inspect as soon as the app starts running on the device.
This screen is familier to most but just wondering if there is a more efficient way of opening the inspect for the web-view without having to wait for app to install then launching the inspector and lastly hitting refresh to get the get the network information.
So some call back like:
cordova run --device OS --launch device-inspect
GapDebug, which seems to be merely a wrapper around chrome inspect, promises a feature like this:
GapDebug detects an app termination and restart, such as during an app update, and automatically reconnects the app with the previous debug session. Quickly get back to debugging when the app closes on your device.
Taken from their features site...
To my knowledge there isn't.
If you make changes to the code you have to compile and install the app on your device or else you won't have the most recent build.
And if I'm not mistaken the way "Inspect" works is by attaching to a running process and you can only start to "listen" after the process has already been created.
Or as #Phonolog sugested, use another debugger

How to automatically connect the Eclipse debugger when the android app is restarted on the device?

I am using Eclipse. I have a breakpoint on onCreate that I want to catch in debug mode when my application is restarted by android because of multitasking. I can connect the Eclipse debugger to my restarted app on the DDMS perspective, but I am never fast enough to catch the breakpoint in onCreate. How to automatically connect the Eclipse debugger when the android app is restarted on the device?
Run the app in debug mode. Right click on project there will a option Debug as below Run as.
Run the app in debug mode. But don't forget to add break point first before running app in debug mode
is restarted by android because of multitasking
Not sure what you really mean by this, but if this imprecise description refers to asynchronous operations (i.e. using AsyncTask) then you may want to add this line before your breakpoint set in code that is run on other than main task:
Debug.waitForDebugger();
Please note that to make it work you need to launch your app in debugging mode (F11)

Android: how to debug app's start-up process

I am investigating some issues which happen during my app's startup process, but DDMS won't start the debug mode until the process has started, is there a way I can capture the events earlier?
I know that this is a couple of years late, but for any future searches:
Putting WaitForDebugger into your code is one way.
Unlocking developer options (by tapping on the build number in system information on the android device) in Settings allows us to select an application for debugging and then opt to wait for a debugger whenever the program is launched. This allows us do the equivalent of adding and removing WaitForDebugger without modifying and reinstalling the code each time.
For Android Studio, here is what worked for me:
Add
android.os.Debug.waitForDebugger();
Where you want to start debugging.
Then add a breakpoint just after it in your code
Compile your app and pass it to your device
Restart your device
Once it's up, attach the debugger:
Start debugging
You should implement your own Application class which extends
Application and override the methods onCreate and so.. . This class will be your starting point of your app.
also set it as your application in the manifest.
Android can wait for the debugger to attach to your application before the app gets launched. This is a developer option called Wait for debugger.
Steps
Enable developer options (tap build version 7 times)
Enable USB debugging
Install your application onto your device using debug mode
In developer options: Press Select debug app and select the app
Enable Wait for debugger, as shown in screenshot:
Launch your app:
e.g. If testing app launch from terminated state from a push notification, send that push notification to the device.
e.g. If testing app launch from Google Assistant, use the Google Assistant to trigger this.
The app would not launch yet, instead a dialog would show up:
Attach the debugger, by pressing the Attach Debugger to Android Process button
My situation
For anyone interested/ for my future reference: I wanted to debug my Android application receiving a push notification message when the app was in the terminated state. It was actually a Flutter app running on Android, so this is relevant for both Android and Flutter.
I have revoked the API key revealed in this GIF.
Tip
If Wait for debugger is enabled, sometimes you need to detach or close Android Studio's debugger and re-attach it if you want to handle a subsequent application launch successfully. Otherwise, the app would never launch.
Notice, I send a push notification from a device (left device, iOS), and the push notification causes the app to launch on the (right device, Android). Then I attach the debugger, and the program pauses at the breakpoint I set inside FirebaseMessagingReceiver.
I wrote another version of these steps here.

Attach Eclipse debugger to restarted application

I am testing the onsave/onrestore mthods of my android application.
To do this I phone my device and see that it kills the process and then I hang up. :)
I see that it restarts the application.
Question is: how do I cause it to restart in debug mode so I can step through the restore process?
Is there a way to tell it to automatically attach to the debugger when starting up?
Use android.os.Debug.waitForDebugger();
Basically, start via debugging. Exit out of your app. Set some break points. Enter back into your app (make sure that this line is hit, so put it in your onCreate or somewhere else) and it will re-attach to the running debugger.
I don't think there is a way to ensure the app restarts in debug mode. But if you are debugging your own app and don't mind adding debug code for testing you might want to add a Thread.sleep(5000) or something like this at an appropriate place in your startup methods. This should give you enough time to reconnect the debugger via the DDMS. Remove when you are done, of course ;)
There is a configuration option in Android settings > developer options > debugging > select app to be debugged. What it does is calling the eclipse debugger every time certain application is opened, if it's connected to the adb and the app's project is open.
Programmatically: Use waitForDebugger(). Documentation here.
Note that the method returns as soon as the debugger attaches, so it's best practice to place a breakpoint right after that call. Additionally, you can test the debugger attachment status using isDebuggerConnected().
In Eclipse: Open the DDMS perspective of eclipse, select the freshly-restarted app on your device, and then select the debug option. This will attach the debugger to the restarted instance.
On the Device: There is a configuration option under some* handsets that allows you to select an app to be debugged when USB debugging is configured. It's under the Developer Options in your device settings. This will attach the debugger automatically.
*For example, my Galaxy S4 has it, my HTC Rezound does not. I believe it might be a Jelly Bean specific option.

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