Develop Reference

android.content.ActivityNotFoundException: Unable to find explicit activity class {com.myapp/androidx.fragment.app.FragmentActivity}

I am using BottomNavigation Menu in my app which has 4 submenus: Address, Dashboard, Home, Notifications.
When I want to startActivity from HomeFragment to Dashboard Fragment it gives me error that I have depicted below.
E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.karatasyazilim.su, PID: 21216
android.content.ActivityNotFoundException: Unable to find explicit activity class {com.karatasyazilim.su/androidx.fragment.app.FragmentActivity}; have you declared this activity in your AndroidManifest.xml?
at android.app.Instrumentation.checkStartActivityResult(Instrumentation.java:2069)
at android.app.Instrumentation.execStartActivity(Instrumentation.java:1717)
at android.app.Activity.startActivityForResult(Activity.java:5252)
at androidx.fragment.app.FragmentActivity.startActivityForResult(FragmentActivity.java:675)
at androidx.core.app.ActivityCompat.startActivityForResult(ActivityCompat.java:234)
at androidx.fragment.app.FragmentActivity.startActivityFromFragment(FragmentActivity.java:790)
at androidx.fragment.app.FragmentActivity$HostCallbacks.onStartActivityFromFragment(FragmentActivity.java:932)
at androidx.fragment.app.Fragment.startActivity(Fragment.java:1257)
at androidx.fragment.app.Fragment.startActivity(Fragment.java:1245)
at com.karatasyazilim.su.ui.home.HomeFragment$5.onClick(HomeFragment.java:333)
at android.view.View.performClick(View.java:7869)
at android.widget.TextView.performClick(TextView.java:14958)
at com.google.android.material.button.MaterialButton.performClick(MaterialButton.java:992)
at android.view.View.performClickInternal(View.java:7838)
at android.view.View.access$3600(View.java:886)
at android.view.View$PerformClick.run(View.java:29362)
at android.os.Handler.handleCallback(Handler.java:883)
at android.os.Handler.dispatchMessage(Handler.java:100)
at android.os.Looper.loop(Looper.java:237)
at android.app.ActivityThread.main(ActivityThread.java:8016)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:496)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1087)
My manifest is :
<?xml version="1.0" encoding="utf-8"?>
<uses-permission android:name="android.permission.INTERNET" />
<application
android:allowBackup="true"
android:icon="#mipmap/ic_launcher"
android:label="#string/app_name"
android:roundIcon="#mipmap/ic_launcher_round"
android:supportsRtl="true"
android:theme="#style/Theme.Su">
<activity android:name=".CreateAddress"></activity>
<activity android:name=".PhoneActivation" />
<activity
android:name=".Genel"
android:label="#string/title_activity_genel" />
<activity android:name=".SignUp" />
<activity android:name=".MainActivity">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<meta-data
android:name="com.facebook.sdk.ApplicationId"
android:value="#string/facebook_app_id" />
<activity
android:name="com.facebook.FacebookActivity"
android:configChanges="keyboard|keyboardHidden|screenLayout|screenSize|orientation"
android:label="#string/app_name" />
<activity
android:name="com.facebook.CustomTabActivity"
android:exported="true">
<intent-filter>
<action android:name="android.intent.action.VIEW" />
<category android:name="android.intent.category.DEFAULT" />
<category android:name="android.intent.category.BROWSABLE" />
<data android:scheme="#string/fb_login_protocol_scheme" />
</intent-filter>
</activity>
</application>
And here is my activiy code.
Intent kalimera = new Intent(getActivity(), FragmentActivity.class);
startActivity(kalimera);
What am I doing wrong?

You're trying to start the androidx FragmentActivity class directly. This is a parent class that you should subclass to create your own Activity.
Instead, make sure that you're using the name of the Activity you want to launch instead:
Intent intent = new Intent(getActivity(), NameOfTheActivityThatYouWantToLaunch.class);
startActivity(intent);
Alternately, if you aren't trying to launch an Activity and just got this code from somewhere, simply remove those lines.
If you're trying to launch a Fragment instead, take a look at How to start Fragment from an Activity

Unable to find explicit activity (Kotlin)

i made a new activity and when i im trying to move between them by clicking a button the app crash and logcat shows the error below
12-16 14:02:09.016 23235-23235/com.modather.scalculate E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.modather.scalculate, PID: 23235
android.content.ActivityNotFoundException: Unable to find explicit activity class {com.modather.scalculate/android.support.v7.widget.AppCompatButton}; have you declared this activity in your AndroidManifest.xml?
at android.app.Instrumentation.checkStartActivityResult(Instrumentation.java)
at android.app.Instrumentation.execStartActivity(Instrumentation.java)
at android.app.Activity.startActivityForResult(Activity.java)
at android.support.v4.app.BaseFragmentActivityApi16.startActivityForResult(BaseFragmentActivityApi16.java:54)
at android.support.v4.app.FragmentActivity.startActivityForResult(FragmentActivity.java:67)
at android.app.Activity.startActivityForResult(Activity.java)
at android.support.v4.app.FragmentActivity.startActivityForResult(FragmentActivity.java:720)
at android.app.Activity.startActivity(Activity.java)
at android.app.Activity.startActivity(Activity.java)
at com.modather.scalculate.HomePage$onCreate$1.onClick(HomePage.kt:36)
at android.view.View.performClick(View.java)
at android.view.View$PerformClick.run(View.java)
at android.os.Handler.handleCallback(Handler.java)
at android.os.Handler.dispatchMessage(Handler.java)
at android.os.Looper.loop(Looper.java)
at android.app.ActivityThread.main(ActivityThread.java)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java)
at de.robv.android.xposed.XposedBridge.main(XposedBridge.java:107)
AndroidManifest.xml
<?xml version="1.0" encoding="utf-8"?>
<application
android:allowBackup="true"
android:icon="#mipmap/ic_launcher"
android:label="#string/app_name"
android:roundIcon="#mipmap/ic_launcher_round"
android:supportsRtl="true"
android:theme="#style/AppTheme">
<activity
android:name=".HomePage"
android:label="#string/app_name"
android:theme="#style/AppTheme.NoActionBar">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity
android:name="com.modather.scalculate.age"
android:label="Calculate my age(SC)" />
</application>
i had searched over stackoverflow and found some solution but it didn't work for me.. so if it possible to fix mine ?
Here's the moving code
fab.setOnClickListener {
val intent = Intent(this, activity_age::class.java)
startActivity(intent)
}

There is Typing mistake check it
your activity name is activity_age and you have added in manifest age is
fab.setOnClickListener {
val intent = Intent(this,age::class.java)
startActivity(intent)
}

On Click error? Start a New Activity or in including another activity?

I have a Application in that I want to add QR reader as a Activity/Module
So,I followed this to Read QR code..
and Here Its working fine..
So I have added this code to My application and I want to use this activity for that I have designed a new activity in that On-click it should start Qr reader..
But I am getting this error...
Here I Tried with this
Button b = (Button) findViewById(R.id.main);
b.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
Intent i = new Intent(Qdata.this,DecoderActivity.class);
startActivity(i);
}
Here DecoderActivity.calass is northig But another application or activity which is Qr reader form the above example so I want to Include this in my activity....
This at Manifest
<activity
android:name=".adata.Qdata"
android:label="#string/app_name" >
<intent-filter>
<action android:name="com.my.adata.Qdata" />
<category android:name="android.intent.category.DEFAULT" />
</intent-filter>
</activity>
<activity
android:name=".adata.DecoderActivity"
android:label="#string/app_name"
android:screenOrientation="portrait">
<intent-filter>
<action android:name="com.my.adata.DecoderActivity" />
<category android:name="android.intent.category.DEFAULT" />
</intent-filter>
</activity>
Actually here adata is a another package in my Application... and Main package is com.my
So in com.my I have another files for QR purpose I have separated this two activities
This is Error
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.my/com.my.adata.DecoderActivity}: java.lang.NullPointerException
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1970)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1995)
at android.app.ActivityThread.access$600(ActivityThread.java:128)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1161)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:137)
at android.app.ActivityThread.main(ActivityThread.java:4517)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:511)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:993)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:760)
at dalvik.system.NativeStart.main(Native Method)
Caused by: java.lang.NullPointerException
at android.support.v7.widget.ToolbarWidgetWrapper.<init>(ToolbarWidgetWrapper.java:98)
at android.support.v7.widget.ToolbarWidgetWrapper.<init>(ToolbarWidgetWrapper.java:91)
at android.support.v7.app.ToolbarActionBar.<init>(ToolbarActionBar.java:73)
at android.support.v7.app.AppCompatDelegateImplV7.setSupportActionBar(AppCompatDelegateImplV7.java:205)
at android.support.v7.app.AppCompatActivity.setSupportActionBar(AppCompatActivity.java:99)
at com.my.adata.DecoderActivity.onCreate(DecoderActivity.java:43)
at android.app.Activity.performCreate(Activity.java:4470)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1053)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1934)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1995) 
at android.app.ActivityThread.access$600(ActivityThread.java:128) 
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1161) 
at android.os.Handler.dispatchMessage(Handler.java:99) 
at android.os.Looper.loop(Looper.java:137) 
at android.app.ActivityThread.main(ActivityThread.java:4517) 
at java.lang.reflect.Method.invokeNative(Native Method) 
at java.lang.reflect.Method.invoke(Method.java:511) 
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:993) 
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:760) 
at dalvik.system.NativeStart.main(Native Method)
 
Can any one suggest me what is problem...

Why are you using two launcher activity try to make one louncher activity and than call your activity.
<activity
android:name=".adata.Main"
android:label="#string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity
android:name="com.my.adata.Qdata">
</activity>

Do this changes in manifest...
<activity
android:name="com.my.adata.Main"
android:label="#string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN"/>
<category android:name="android.intent.category.LAUNCHER">
</intent-filter>
</activity>
<activity
android:name="com.my.adata.Qdata"
android:screenOrientation="portrait">
<intent-filter>
<action android:name="com.my.adata.Qdata" />
<category android:name="android.intent.category.DEFAULT" />
</intent-filter>
</activity>

Launching Android Activity from adb shell

I have an android application installed on my phone and i would like to launch one of the activities through the adb shell. Here is the manifest of the file:
EDIT I have also posted the logcat info below all of the manifest code and adb commands. It is throwing a NullPointerException.
<?xml version="1.0" encoding="utf-8"?>
<manifest android:versionCode="2010100" android:versionName="2.1.1" package="com.aurorasoftworks.quadrant.ui.standard"
xmlns:android="http://schemas.android.com/apk/res/android">
<supports-screens android:anyDensity="true" android:smallScreens="true" android:normalScreens="true" android:largeScreens="true" />
<application android:label="#string/app_name" android:icon="#drawable/icon" android:name="com.aurorasoftworks.quadrant.ui.standard.QuadrantStandardApplication">
<activity android:label="#string/app_name" android:name=".QuadrantStandardLauncherActivity" android:noHistory="true">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity android:label="#string/app_name" android:name=".QuadrantStandardActivity" />
<activity android:label="#string/app_name" android:name="com.aurorasoftworks.quadrant.ui.runner.BenchmarkExecutionActivity" android:screenOrientation="portrait" android:noHistory="true" />
<activity android:label="#string/app_name" android:name="com.aurorasoftworks.quadrant.ui.score.BenchmarkScoreActivity" />
<activity android:label="#string/app_name" android:name="com.aurorasoftworks.quadrant.ui.browser.DeviceVendorListActivity" />
<activity android:label="#string/app_name" android:name="com.aurorasoftworks.quadrant.ui.browser.DeviceListActivity" />
<activity android:label="#string/app_name" android:name="com.aurorasoftworks.quadrant.ui.browser.DeviceStatsActivity" />
<activity android:label="#string/app_name" android:name="com.aurorasoftworks.quadrant.ui.sysinfo.SystemInfoActivity" />
<activity android:name="com.google.ads.AdActivity" android:configChanges="keyboard|keyboardHidden|orientation" />
</application>
<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
<uses-permission android:name="android.permission.SET_ORIENTATION" />
</manifest>
I tried launching the QuadrantStandardActivity using the command:
adb shell am start -n com.aurorasoftworks.quadrant.ui.standard/.QuadrantStandardActivity
and it worked. But when I tried to connect to another activity it failed. The command I used was:
adb shell am start -n com.aurorasoftworks.quadrant.ui.standard/com.aurorasoftworks.quadrant.ui.runner.BenchmarkExecutionActivity
Logcat Info:
E/AndroidRuntime(11973): FATAL EXCEPTION: main
E/AndroidRuntime(11973): java.lang.NullPointerException
E/AndroidRuntime(11973): at com.aurorasoftworks.quadrant.core.C.a(Unknown Source)
E/AndroidRuntime(11973): at com.aurorasoftworks.quadrant.ui.runner.A.a(Unknown Source)
E/AndroidRuntime(11973): at com.aurorasoftworks.quadrant.ui.runner.BenchmarkExecutionActivity.h(Unknown Source)
E/AndroidRuntime(11973): at com.aurorasoftworks.quadrant.ui.runner.r.apply$mcV$sp(Unknown Source)
E/AndroidRuntime(11973): at com.aurorasoftworks.quadrant.ui.runner.r.a(Unknown Source)
E/AndroidRuntime(11973): at com.aurorasoftworks.quadrant.ui.runner.r.apply(Unknown Source)
E/AndroidRuntime(11973): at com.aurorasoftworks.quadrant.util.r.run(Unknown Source)
E/AndroidRuntime(11973): at android.os.Handler.handleCallback(Handler.java:725)
E/AndroidRuntime(11973): at android.os.Handler.dispatchMessage(Handler.java:92)
E/AndroidRuntime(11973): at android.os.Looper.loop(Looper.java:137)
E/AndroidRuntime(11973): at android.app.ActivityThread.main(ActivityThread.java:5074)
E/AndroidRuntime(11973): at java.lang.reflect.Method.invokeNative(Native Method)
E/AndroidRuntime(11973): at java.lang.reflect.Method.invoke(Method.java:511)
E/AndroidRuntime(11973): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
E/AndroidRuntime(11973): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
E/AndroidRuntime(11973): at dalvik.system.NativeStart.main(Native Method)
W/ActivityManager( 739): Force finishing activity com.aurorasoftworks.quadrant.ui.standard/com.aurorasoftworks.quadrant.ui.runner.BenchmarkExecutionActivity
W/ActivityManager( 739): Force finishing activity com.aurorasoftworks.quadrant.ui.standard/.QuadrantStandardActivity
W/ActivityManager( 739): Activity pause timeout for ActivityRecord{413150d0 u0 com.aurorasoftworks.quadrant.ui.standard/com.aurorasoftworks.quadrant.ui.runner.BenchmarkExecutionActivity}
I/ActivityManager( 739): Process com.aurorasoftworks.quadrant.ui.standard (pid 11973) has died.
I would appreciate any help

when start the BenchmarkExecutionActivity throws a NullPointerException,check the code why throws the exception.

.BenchmarkExecutionActivity
should be in
com.aurorasoftworks.quadrant.ui.standard
package. either change your package name in the first line of manifest from
package="com.aurorasoftworks.quadrant.ui.standard"
to
package="com.aurorasoftworks.quadrant.ui"
or put that activity inside
com.aurorasoftworks.quadrant.ui.standard
package.

How to fix this classnotfound exception in Android?

I got the stack trace below in the Android developer account. There is just one occurrence of this error.
java.lang.RuntimeException: Unable to instantiate application com.mysite.myapp.TestApplication: java.lang.ClassNotFoundException: com.mysite.myapp.TestApplication in loader dalvik.system.PathClassLoader[/data/app-private/com.mysite.myapp-2.apk]
at android.app.LoadedApk.makeApplication(LoadedApk.java:466)
at android.app.ActivityThread.handleBindApplication(ActivityThread.java:3268)
at android.app.ActivityThread.access$2200(ActivityThread.java:117)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:973)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:130)
at android.app.ActivityThread.main(ActivityThread.java:3691)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:507)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:912)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:670)
at dalvik.system.NativeStart.main(Native Method)
Caused by: java.lang.ClassNotFoundException: com.myapp.myapp.TestApplication in loader dalvik.system.PathClassLoader[/data/app-private/com.mysite.myapp-2.apk]
at dalvik.system.PathClassLoader.findClass(PathClassLoader.java:240)
at java.lang.ClassLoader.loadClass(ClassLoader.java:551)
at java.lang.ClassLoader.loadClass(ClassLoader.java:511)
at android.app.Instrumentation.newApplication(Instrumentation.java:945)
at android.app.LoadedApk.makeApplication(LoadedApk.java:461)
... 11 more
In my manifest file, I have declared com.mysite.myapp.TestApplication.
My Manifest file looks like this:
<application
android:name="com.mysite.myapp.TestApplication"
android:icon="#drawable/app_icon"
android:label="#string/app_name"
android:theme="#style/Theme.myapp" >
<activity
android:name="com.mysite.myapp.ActivityDashboard"
android:configChanges="orientation|keyboard"
android:label="#string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
...

If your main home page is ActivityDashboard.java
insert as below or if TestApplication.java
replace .ActivityDashboard as .TestApplication in the activity tag
<package name="com.mysite.myapp"
<application
android:name="TestApplication"
android:icon="#drawable/app_icon"
android:label="#string/app_name"
android:theme="#style/Theme.myapp" >
<activity android:name=".ActivityDashboard" android:configChanges="orientation|keyboard"
android:label="#string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
......
</application>

android:name="com.mysite.myapp.ActivityDashboard"
Replace thr above in your manifest with the below.
android:name=".ActivityDashboard"
Alternatively:
android:name="com.mysite.myapp.TestApplication.ActivityDashboard"