Retrieve logs from an Android device

Overview

Use Android Debug Bridge (ADB) to capture device logs (logcat) for troubleshooting.

If you can reproduce the issue in a controlled environment, capture logs right around the failing flow.

If you need SDK runtime logs that stay inside the application sandbox, use LogService instead. See Collect logs with LogService.

Prerequisites

Before you can retrieve the log files from an Android device, ensure that you have done the following setup:

• Install Android Debug Bridge (ADB) on the host machine.
• Enable USB debugging on the device under test.
• Connect the Android device to the host machine using a USB cable.
• Install the device USB driver on Windows (if required).

To verify the setup, run:

adb devices

The device is reachable when you see an entry with status device:

List of devices attached
228b0e100d047ece device

If you do not see the device, re-check the prerequisites. For ADB setup and troubleshooting, see the official Android documentation: Android Debug Bridge (adb).

Some devices require enabling device logging in a vendor-specific menu.

For example, on some Huawei devices you can access the menu by dialing *#*#2846579#*#*. See Huawei logcat not showing the log for my app for context.

Capture logs (recommended)

1. Clear device log buffers:

   adb logcat -b all -c

2. Start capturing logs (millisecond timestamps, all priorities):

   adb logcat -v threadtime -b all *:V > TestLogFileName.txt

3. Reproduce the issue in your digital wallet application.
4. Stop capture and collect the file:

   • Press CTRL+C.
   • Retrieve TestLogFileName.txt from the folder where you ran the command.

For the most detailed logs, reproduce using a build of your digital wallet application that integrates the NFC Wallet SDK dev build.

See Deliverables for supported build types.

Capture logs only around the failing flow. Start right before the steps. Stop right after.

Avoid logcat filters. They often hide the lines needed for root-cause analysis.

Verifying the setup

You can verify the setup by running a flow that calls the SDK API, for example Retrieve card list in Display digital cards.

With the recommended command, the log file should have:

• A timestamp with millisecond precision on each line.
• Log priority letters up to V (Verbose) after the PID and TID fields.
• A line containing PublicAPI::Start of DigitalizedCardManager.getAllCards.

The following example shows the log snippet demonstrating such features:

08-06 17:11:21.790 14171 14171 D SDK_ENTRY_POINT: PublicAPI::Start of DigitalizedCardManager.getAllCards
08-06 17:11:21.790 14171 14171 D SDK_ENTRY_POINT: PublicAPI::Start of SDKController.getInstance
08-06 17:11:21.791 14171 14171 D SDK_ENTRY_POINT: PublicAPI::Start of SDKController.getService
08-06 17:11:21.791 14171 14171 V util.h.xy.by.mb: Attempting to retrieve service with name: DigitalizedCardBuinsessService
08-06 17:11:21.791 14171 14171 D util.h.xy.by.mb: business service = util.h.xy.l.a@f9a06e1
08-06 17:11:21.791 14171 14171 V util.h.xy.l.a: getAllCards is called
08-06 17:11:21.791 14171 14171 D util.h.xy.aj.b: [DCM.getAllCards].increment
08-06 17:11:21.791 14171 14171 V util.h.xy.aj.b: [DCM.getAllCards]Ops left is 1
08-06 17:11:21.792 14171 18982 I util.h.xy.n.mb: -----------------------------------------------------------------------GET_ALLCARDS-START----------------------------------------------------------------------