Develop Reference

How to fix Error: Unknown component while launching activity when pushing the app to a device?

Sometimes (not all times) when I try to push (simply run) the code the from android-studio to my phone (Motorola 3G, though not phone specific), I am getting this error :-
04/22 23:00:14: Launching app
No local changes, not deploying APK
$ adb shell am start -n "com.xxxx.test/com.horntell.test.MainActivity" -a android.intent.action.MAIN -c android.intent.category.LAUNCHER
Error while executing: am start -n "com.horntell.test/com.horntell.test.MainActivity" -a android.intent.action.MAIN -c android.intent.category.LAUNCHER
Starting: Intent { act=android.intent.action.MAIN cat=[android.intent.category.LAUNCHER] cmp=com.horntell.test/.MainActivity }
usage: am [subcommand] [options]
usage: am start [-D] [-W] [-P <FILE>] [--start-profiler <FILE>]
[--sampling INTERVAL] [-R COUNT] [-S] [--opengl-trace]
[--user <USER_ID> | current] <INTENT>
am startservice [--user <USER_ID> | current] <INTENT>
am stopservice [--user <USER_ID> | current] <INTENT>
am force-stop [--user <USER_ID> | all | current] <PACKAGE>
am kill [--user <USER_ID> | all | current] <PACKAGE>
am kill-all
am broadcast [--user <USER_ID> | all | current] <INTENT>
am instrument [-r] [-e <NAME> <VALUE>] [-p <FILE>] [-w]
[--user <USER_ID> | current]
[--no-window-animation] [--abi <ABI>] <COMPONENT>
am profile start [--user <USER_ID> current] [--sampling INTERVAL] <PROCESS> <FILE>
am profile stop [--user <USER_ID> current] [<PROCESS>]
am dumpheap [--user <USER_ID> current] [-n] <PROCESS> <FILE>
am set-debug-app [-w] [--persistent] <PACKAGE>
am clear-debug-app
am set-watch-heap <PROCESS> <MEM-LIMIT>
am clear-watch-heap
am monitor [--gdb <port>]
am hang [--allow-restart]
am restart
am idle-maintenance
am screen-compat [on|off] <PACKAGE>
am package-importance <PACKAGE>
am to-uri [INTENT]
am to-intent-uri [INTENT]
am to-app-uri [INTENT]
am switch-user <USER_ID>
am start-user <USER_ID>
am stop-user [-w] <USER_ID>
am stack start <DISPLAY_ID> <INTENT>
am stack movetask <TASK_ID> <STACK_ID> [true|false]
am stack resize <STACK_ID> <LEFT,TOP,RIGHT,BOTTOM>
am stack split <STACK_ID> <v|h> [INTENT]
am stack list
am stack info <STACK_ID>
am task lock <TASK_ID>
am task lock stop
am task resizeable <TASK_ID> [true|false]
am task resize <TASK_ID> <LEFT,TOP,RIGHT,BOTTOM>
am get-config
am set-inactive [--user <USER_ID>] <PACKAGE> true|false
am get-inactive [--user <USER_ID>] <PACKAGE>
am send-trim-memory [--user <USER_ID>] <PROCESS>
[HIDDEN|RUNNING_MODERATE|BACKGROUND|RUNNING_LOW|MODERATE|RUNNING_CRITICAL|COMPLETE]
am start: start an Activity. Options are:
-D: enable debugging
-W: wait for launch to complete
--start-profiler <FILE>: start profiler and send results to <FILE>
--sampling INTERVAL: use sample profiling with INTERVAL microseconds
between samples (use with --start-profiler)
-P <FILE>: like above, but profiling stops when app goes idle
-R: repeat the activity launch <COUNT> times. Prior to each repeat,
the top activity will be finished.
-S: force stop the target app before starting the activity
--opengl-trace: enable tracing of OpenGL functions
--user <USER_ID> | current: Specify which user to run as; if not
specified then run as the current user.
am startservice: start a Service. Options are:
--user <USER_ID> | current: Specify which user to run as; if not
specified then run as the current user.
am stopservice: stop a Service. Options are:
--user <USER_ID> | current: Specify which user to run as; if not
specified then run as the current user.
am force-stop: force stop everything associated with <PACKAGE>.
--user <USER_ID> | all | current: Specify user to force stop;
all users if not specified.
am kill: Kill all processes associated with <PACKAGE>. Only kills.
processes that are safe to kill -- that is, will not impact the user
experience.
--user <USER_ID> | all | current: Specify user whose processes to kill;
all users if not specified.
am kill-all: Kill all background processes.
am broadcast: send a broadcast Intent. Options are:
--user <USER_ID> | all | current: Specify which user to send to; if not
specified then send to all users.
--receiver-permission <PERMISSION>: Require receiver to hold permission.
am instrument: start an Instrumentation. Typically this target <COMPONENT>
is the form <TEST_PACKAGE>/<RUNNER_CLASS>. Options are:
-r: print raw results (otherwise decode REPORT_KEY_STREAMRESULT). Use with
[-e perf true] to generate raw output for performance measurements.
-e <NAME> <VALUE>: set argument <NAME> to <VALUE>. For test runners a
common form is [-e <testrunner_flag> <value>[,<value>...]].
-p <FILE>: write profiling data to <FILE>
-w: wait for instrumentation to finish before returning. Required for
test runners.
--user <USER_ID> | current: Specify user instrumentation runs in;
current user if not specified.
--no-window-animation: turn off window animations while running.
--abi <ABI>: Launch the instrumented process with the selected ABI.
This assumes that the process supports the selected ABI.
am profile: start and stop profiler on a process. The given <PROCESS> argument
may be either a process name or pid. Options are:
--user <USER_ID> | current: When supplying a process name,
specify user of process to profile; uses current user if not specified.
am dumpheap: dump the heap of a process. The given <PROCESS> argument may
be either a process name or pid. Options are:
-n: dump native heap instead of managed heap
--user <USER_ID> | current: When supplying a process name,
specify user of process to dump; uses current user if not specified.
am set-debug-app: set application <PACKAGE> to debug. Options are:
-w: wait for debugger when application starts
--persistent: retain this value
am clear-debug-app: clear the previously set-debug-app.
am set-watch-heap: start monitoring pss size of <PROCESS>, if it is at or
above <HEAP-LIMIT> then a heap dump is collected for the user to report
am clear-watch-heap: clear the previously set-watch-heap.
am bug-report: request bug report generation; will launch UI
when done to select where it should be delivered.
am monitor: start monitoring for crashes or ANRs.
--gdb: start gdbserv on the given port at crash/ANR
am hang: hang the system.
--allow-restart: allow watchdog to perform normal system restart
am restart: restart the user-space system.
am idle-maintenance: perform idle maintenance now.
am screen-compat: control screen compatibility mode of <PACKAGE>.
am package-importance: print current importance of <PACKAGE>.
am to-uri: print the given Intent specification as a URI.
am to-intent-uri: print the given Intent specification as an intent: URI.
am to-app-uri: print the given Intent specification as an android-app: URI.
am switch-user: switch to put USER_ID in the foreground, starting
execution of that user if it is currently stopped.
am start-user: start USER_ID in background if it is currently stopped,
use switch-user if you want to start the user in foreground.
am stop-user: stop execution of USER_ID, not allowing it to run any
code until a later explicit start or switch to it.
-w: wait for stop-user to complete.
am stack start: start a new activity on <DISPLAY_ID> using <INTENT>.
am stack movetask: move <TASK_ID> from its current stack to the top (true) or bottom (false) of <STACK_ID>.
am stack resize: change <STACK_ID> size and position to <LEFT,TOP,RIGHT,BOTTOM>.
am stack split: split <STACK_ID> into 2 stacks <v>ertically or <h>orizontally
starting the new stack with [INTENT] if specified. If [INTENT] isn't
specified and the current stack has more than one task, then the top task
of the current task will be moved to the new stack. Command will also force
all current tasks in both stacks to be resizeable.
am stack list: list all of the activity stacks and their sizes.
am stack info: display the information about activity stack <STACK_ID>.
am task lock: bring <TASK_ID> to the front and don't allow other tasks to run.
am task lock stop: end the current task lock.
am task resizeable: change if <TASK_ID> is resizeable (true) or not (false).
am task resize: makes sure <TASK_ID> is in a stack with the specified bounds.
Forces the task to be resizeable and creates a stack if no existing stack
has the specified bounds.
am get-config: retrieve the configuration and any recent configurations
of the device.
am set-inactive: sets the inactive state of an app.
am get-inactive: returns the inactive state of an app.
am send-trim-memory: Send a memory trim event to a <PROCESS>.
<INTENT> specifications include these flags and arguments:
[-a <ACTION>] [-d <DATA_URI>] [-t <MIME_TYPE>]
[-c <CATEGORY> [-c <CATEGORY>] ...]
[-e|--es <EXTRA_KEY> <EXTRA_STRING_VALUE> ...]
[--esn <EXTRA_KEY> ...]
[--ez <EXTRA_KEY> <EXTRA_BOOLEAN_VALUE> ...]
[--ei <EXTRA_KEY> <EXTRA_INT_VALUE> ...]
[--el <EXTRA_KEY> <EXTRA_LONG_VALUE> ...]
[--ef <EXTRA_KEY> <EXTRA_FLOAT_VALUE> ...]
[--eu <EXTRA_KEY> <EXTRA_URI_VALUE> ...]
[--ecn <EXTRA_KEY> <EXTRA_COMPONENT_NAME_VALUE>]
[--eia <EXTRA_KEY> <EXTRA_INT_VALUE>[,<EXTRA_INT_VALUE...]]
(mutiple extras passed as Integer[])
[--eial <EXTRA_KEY> <EXTRA_INT_VALUE>[,<EXTRA_INT_VALUE...]]
(mutiple extras passed as List<Integer>)
[--ela <EXTRA_KEY> <EXTRA_LONG_VALUE>[,<EXTRA_LONG_VALUE...]]
(mutiple extras passed as Long[])
[--elal <EXTRA_KEY> <EXTRA_LONG_VALUE>[,<EXTRA_LONG_VALUE...]]
(mutiple extras passed as List<Long>)
[--efa <EXTRA_KEY> <EXTRA_FLOAT_VALUE>[,<EXTRA_FLOAT_VALUE...]]
(mutiple extras passed as Float[])
[--efal <EXTRA_KEY> <EXTRA_FLOAT_VALUE>[,<EXTRA_FLOAT_VALUE...]]
(mutiple extras passed as List<Float>)
[--esa <EXTRA_KEY> <EXTRA_STRING_VALUE>[,<EXTRA_STRING_VALUE...]]
(mutiple extras passed as String[]; to embed a comma into a string,
escape it using "\,")
[--esal <EXTRA_KEY> <EXTRA_STRING_VALUE>[,<EXTRA_STRING_VALUE...]]
(mutiple extras passed as List<String>; to embed a comma into a string,
escape it using "\,")
[--grant-read-uri-permission] [--grant-write-uri-permission]
[--grant-persistable-uri-permission] [--grant-prefix-uri-permission]
[--debug-log-resolution] [--exclude-stopped-packages]
[--include-stopped-packages]
[--activity-brought-to-front] [--activity-clear-top]
[--activity-clear-when-task-reset] [--activity-exclude-from-recents]
[--activity-launched-from-history] [--activity-multiple-task]
[--activity-no-animation] [--activity-no-history]
[--activity-no-user-action] [--activity-previous-is-top]
[--activity-reorder-to-front] [--activity-reset-task-if-needed]
[--activity-single-top] [--activity-clear-task]
[--activity-task-on-home]
[--receiver-registered-only] [--receiver-replace-pending]
[--selector]
[<URI> | <PACKAGE> | <COMPONENT>]
Error: Unknown component: com.horntell.test/com.horntell.test.MainActivity
Error while Launching activity
This problem occur mostly when I try to push the code for the first time. i.e. App is not already present in the phone.
Sometimes, I have to restart the IDE, or phone or both to resolve this issue and it gets really frustrating sometimes.

I am not sure but I faced a similar problem with Moto mobiles. In Motorola there are user profiles. So if I had more than one user profile then I got similar error in the case when the app was uninstalled from one of the profiles but not the other.
So you should try uninstalling the app from all the user profiles before installing it again.

Is there a way to check if Android device screen is locked via adb?

I know that PowerManager and/or KeyguardManager can help me check if a device screen is locked/unlocked. Is there a way to check this via adb?

This command will output everything relating to power for the device:
adb shell dumpsys power
You can pipe this to a grep to get the values of mHoldingWakeLockSuspendBlocker and mHoldingDisplaySuspendBlocker:
adb shell dumpsys power | grep 'mHolding'
If both are false, the display is off.
If mHoldingWakeLockSuspendBlocker is false, and mHoldingDisplaySuspendBlocker is true, the display is on, but locked.
If both are true, the display is on.

Since Lollipop PowerManager.isInteractive() and TrustManager.isDeviceLocked() are the proper methods to check if the device's screen is on and unlocked.
And their corresponding service call commands would be:
adb shell service call power 12
and
adb shell service call trust 7
And this is how it can be checked from Python code without having to find Android version specific service call codes for your device - https://gist.github.com/ktnr74/60ac7bcc2cd17b43f2cb

This works only when device has NFC:
# returns one of: mScreenState=OFF|ON_LOCKED|ON_UNLOCKED
adb shell dumpsys nfc | grep 'mScreenState='
OFF - Screen off
ON_LOCKED - Screen displays locked screen
ON_UNLOCKED - device unlocked

Summry other (#Vouskopes, etc) answer here:
My Phone: XiaoMi 9
Android: 10
use adb to check status of screen locked
method 1: (universal) use mDreamingLockscreen
Command: adb shell dumpsys window | grep mDreamingLockscreen
Output:
mShowingDream=false mDreamingLockscreen=true mDreamingSleepToken=null -> Screen Locked
no matter Screen is ON or OFF
mShowingDream=false mDreamingLockscreen=false mDreamingSleepToken=null -> Scrren Unlocked
method 2: use nfc (if android has NFC module)
Command: adb shell dumpsys nfc | grep 'mScreenState='
Output:
mScreenState=OFF_LOCKED -> Screen OFF and Locked
mScreenState=ON_LOCKED -> Screen ON and Locked
mScreenState=ON_UNLOCKED -> Screen ON and Unlocked

Bryan's solution didn't work for my device (Samsung Galaxy S3 running version 4.4.2).
For my KitKat GS3:
I can reliably tell if the screen is on by checking for mScreenOn=true (works regardless of screen lock state).
I can reliably tell if screen is unlocked by checking for mUserActivityTimeoutOverrideFromWindowManager=-1 (works regardless of screen ON or OFF).
If that doesn't work for you, I'd recommend you try the following:
Lock phone & turn off screen then run:
adb shell dumpsys power > dumpsys.power.screen_off.locked.txt
Wake phone & keep it locked then run:
adb shell dumpsys power > dumpsys.power.screen_on.locked.txt
Keep phone awake and unlock screen then run:
adb shell dumpsys power > dumpsys.power.screen_on.unlocked.txt
Turn screen off, but don't lock it then run:
adb shell dumpsys power > dumpsys.power.screen_off.unlocked.txt
Then use a text diffing tool (like winmerge) to look for differences between the .txt files.

One adb command I'm using is:
adb shell dumpsys window
This returns a few system variables that are useful such as mAwake, mShowingLockscreen, mScreenOnEarly, mScreenOnFully.
To figure out which correspond to a locked/unlocked screen, I used adb shell dumpsys window > <textFileNameOfYourChoice>
tl;dr
The combination that I'm finding to be persistent is:
Device is locked AND screen is off:
mAwake=false AND mShowingLockscreen=true
Device is locked AND screen is on:
mAwake=true AND mShowingLockscreen=true
Device is unlocked AND screen is on:
mAwake=true AND mShowingLockscreen=false

Attach a phone and run this code.
Press the power button, and see the changes that happen.
Unlock the phone and see the changes that happen.
Experiment. Have fun.
import re
import subprocess
import time
states = {
'no_cached_wake_locks': '',
'mDirty': '',
'mWakefulness': '',
'mWakefulnessChanging': '',
'mIsPowered': '',
'mPlugType': '',
'mBatteryLevel': '',
'mBatteryLevelCriticalLow': '',
'mLastBatteryLevelCriticalLowTime': '',
'mBatteryLevelWhenDreamStarted': '',
'mDockState': '',
'mStayOn': '',
'mProximityPositive': '',
'mBootCompleted': '',
'mSystemReady': '',
'mHalAutoSuspendModeEnabled': '',
'mHalInteractiveModeEnabled': '',
'mWakeLockSummary': '',
'mUserActivitySummary': '',
'mRequestWaitForNegativeProximity': '',
'mSandmanScheduled': '',
'mSandmanSummoned': '',
'mLowPowerModeEnabled': '',
'mBatteryLevelLow': '',
'mLightDeviceIdleMode': '',
'mDeviceIdleMode': '',
'mScreenBrightnessBoostInProgress': '',
'mDisplayReady': '',
'mHoldingWakeLockSuspendBlocker': '',
'mHoldingDisplaySuspendBlocker': '',
}
def checkit():
cmd = ['adb', 'shell', 'dumpsys', 'power']
proc = subprocess.Popen(cmd,
bufsize=0,
universal_newlines=True,
stdin=None,
stdout=subprocess.PIPE,
stderr=subprocess.STDOUT)
changes = 0
for line2 in proc.stdout.readlines():
line = line2.strip()
for state, value in states.items():
m = re.search(r'{}=(.*)'.format(state), line)
if m:
if value != m.group(1):
changes += 1
print("changed: state={} old={} new={}".format(state, value, m.group(1)))
states[state] = m.group(1)
if changes > 0:
print("---- {} changes".format(changes))
while True:
checkit()
time.sleep(0.5)
For exanple, these are the changes that happen after you lock the phone and the screen is black:
changed: state=mWakefulness old=Awake new=Asleep
changed: state=mHalAutoSuspendModeEnabled old=false new=true
changed: state=mHalInteractiveModeEnabled old=true new=false
changed: state=mUserActivitySummary old=0x4 new=0x0
changed: state=mHoldingDisplaySuspendBlocker old=true new=false
---- 5 changes
changed: state=mWakeLockSummary old=0x1 new=0x0
changed: state=mHoldingWakeLockSuspendBlocker old=true new=false
---- 2 changes
changed: state=mWakeLockSummary old=0x0 new=0x1
changed: state=mHoldingWakeLockSuspendBlocker old=false new=true
---- 2 changes
changed: state=mWakeLockSummary old=0x1 new=0x0
changed: state=mHoldingWakeLockSuspendBlocker old=true new=false
---- 2 changes

If its a rooted phone you can check some fields related to lock in settings.db.
settings.db is located at /data/data/com.android.providers.settings/databases

try adb shell dumpsys window | grep mCurrentFocus | grep StatusBar;
since all unlocked status(include wrong PIN) executed by this CMD return mCurrentFocus=Window{343b978 u0 StatusBar}
example like:
#!/bin/bash
if adb shell dumpsys window | grep mCurrentFocus | grep -q StatusBar; then
echo 'phone is locked';
exit 0;
fi
echo 'phone is unlocked'
By Android 10;

Worked with my Galaxy Note + (Locked with passcode)
unlock() {
if adb shell dumpsys window | grep mCurrentFocus | grep -n NotificationShade; then
adb shell 'input keyevent 26 && input keyevent 82'
if adb shell dumpsys window | grep mCurrentFocus | grep -n Bouncer; then
echo "Device was locked"
adb shell 'input text 12345678 && input keyevent 66'
fi
fi
}

Omitting the lock status ; things that work on Android 12 and 13 :
IMPORTANT : those return nothing after the device been restarted.
if the three commands below return "", use "adb shell input keyevent 26" and try again.
adb shell getprop debug.tracing.screen_state
"2" means screen ON
Note : Does NOT work on older Android versions (9, 10 .. )
adb shell dumpsys input_method | grep -i screenon
Result : "screenOn = false" or "screenOn = true"
Notes :
slower than other two commands (~2 sec)
does not work on all models; use the two other options in those case
adb shell dumpsys power | grep mWakefulness= | head -1
Screen ON gives mWakefulness=Awake
Notes :
grep with "=" to avoid "mWakefulnessChanging"
make sure to look for "=Awake" because some device return "Partial awake" just after screen turned off
does not work on all models; use the two other options

How to start this activity use adb shell am start -D -d pg/xx.The activity name is Main$Activity

I want to debug android's so file. I use start an Activity: am start [-D] [-W] to start activitey.
the applicationg package name is com.dualboot.apps.springzen . the main activity is com.dualboot.apps.springzen.Main$Activity . i use command
'adb shell am start com.dualboot.apps.springzen/com.dualboot.springzen.Main$Actinity'
it's not exist
Starting: Intent { act=android.intent.action.MAIN cat=[android.intent.category.LAUNCHER] cmp=com.dualboot.apps.springzen/com.dualboot.springzen.Main }
Error type 3
Error: Activity class {com.dualboot.apps.springzen/com.dualboot.springzen.Main} does not exist.
how to start this activity

Since you are calling a component you need to include the component -n option tag.
Use this:
adb shell am start -n com.dualboot.apps.springzen/.MainActivity
if you actually have the $ in your class name (I doubt it) which usually refers to an inner class then you need to use:
adb shell am start -n com.dualboot.apps.springzen/.Main\$Activity

How do I get the content of excuting commend with Su?

When I excuted a commend, such as am start -W -n com.xxx.xxx/.xxActivity
I can see the content.
Starting: Intent { cmp=com.xxx.xxx/.xxActivity }
Status: ok
Activity: com.xxx.xxx/.xxActivity
ThisTime: 52
TotalTime: 71
Complete
But when I excuted a commend with su ,such as su -c "am start -W -n com.xxx.xxx/.xxActivity"
there is nothing to output, how can I get the output with su?

The standard Android su works as expected if run properly:
$ su 0 am start -W -n com.android.settings/.Settings
Starting: Intent { cmp=com.android.settings/.Settings }
Warning: Activity not started, its current task has been brought to the front
Status: ok
Activity: com.android.settings/.Settings
ThisTime: 0
TotalTime: 0
Complete
Here's an excerpt from the su.c code:
/*
* SU can be given a specific command to exec. UID _must_ be
* specified for this (ie argc => 3).
*
* Usage:
* su 1000
* su 1000 ls -l
* or
* su [uid[,gid[,group1]...] [cmd]]
* E.g.
* su 1000,shell,net_bw_acct,net_bw_stats id
* will return
* uid=1000(system) gid=2000(shell) groups=3006(net_bw_stats),3007(net_bw_acct)
*/

Android dumpsys activity output format

After this command
adb shell dumpsys activity p | grep <package>
I get this output:
*APP* UID 10060 ProcessRecord{41941528 23873:com.example.testservicestate/u0a60}
dir=/data/app/com.example.testservicestate-1.apk publicDir=/data/app/com.example.testservicestate-1.apk data=/data/data/com.example.testservicestate
packageList={com.example.testservicestate}
- ActivityRecord{42073a50 u0 com.example.testservicestate/.MainActivity t211}
Proc # 0: fore F/A/T trm: 0 23873:com.example.testservicestate/u0a60 (top-activity)
PID #23873: ProcessRecord{41941528 23873:com.example.testservicestate/u0a60}
Which is the meaning of those infos or where can I find the format for this command.
Especially Iḿ interested in those letters F/A/T . Thanks!

As usual you can find all the info in the Android source code.
In this case F/A/T stands for the activity in question being a foreground activity (A) and its process being in PROCESS_STATE_TOP state (T) and belonging to the THREAD_GROUP_DEFAULT scheduling group (F)