We Keep Coding

How to fix **error: cannot find symbol** when importing kotlin package into MainApplication.java for Android in React Native app?

I'm building a react native app that uses the react-native-vision-camera by Mrousavy (https://github.com/mrousavy/react-native-vision-camera) and I'm trying to create a frame processor plugin, following this guide https://mrousavy.com/react-native-vision-camera/docs/guides/frame-processors-plugins-android, which is basically a piece of native code, in this case Kotlin, that process the camera stream, frame by frame.
However, I've tried it several times and I keep getting this error related to Kotlin/Java code:
error Failed to install the app. Make sure you have the Android development environment set up: https://reactnative.dev/docs/environment-setup.
Error: Command failed: ./gradlew app:installDebug -PreactNativeDevServerPort=8081
Warning: unexpected element (uri:"", local:"base-extension"). Expected elements are <{}codename>,<{}layoutlib>,<{}api-level>
/home/luciano/wildsense/nam-vital-signs/rn/RNCamera0/android/app/src/main/java/com/rncamera0/MainApplication.java:16: error: cannot find symbol
import com.rncamera0.BasicFrameProcessorPluginPackage;
^
symbol: class BasicFrameProcessorPluginPackage
location: package com.rncamera0
/home/luciano/wildsense/nam-vital-signs/rn/RNCamera0/android/app/src/main/java/com/rncamera0/MainApplication.java:33: error: cannot find symbol
packages.add(new BasicFrameProcessorPluginPackage());
^
symbol: class BasicFrameProcessorPluginPackage
Note: /home/luciano/wildsense/nam-vital-signs/rn/RNCamera0/android/app/src/debug/java/com/rncamera0/ReactNativeFlipper.java uses or overrides a deprecated API.
Note: Recompile with -Xlint:deprecation for details.
2 errors
FAILURE: Build failed with an exception.
* What went wrong:
Execution failed for task ':app:compileDebugJavaWithJavac'.
As far as I understand, there's a problem with how I'm importing and using the class BasicFrameProcessorPluginPackage but nothing of what I've tried fix it.
The file that contains the error (MainApplication.java), and the two files for the code I want to add (BasicFrameProcessorPlugin.kt and BasicFrameProcessorPluginPackage.kt) are in the same directory(.../android/app/src/main/java/com/rncamera0), and all of them have package com.rncamera0 as the first line.
Being that said, I will appreciate any help to find the solution to the error.

compilation failed "Task :app:compileDebugJavaWithJavac FAILED"

this error randomly popped up after i tried running my ionic cordova app. this not only happens on my branch ive been working on but also with every other branch i try to run, which leads me to believe it is something with my machine. ive tried restarting and reinstalling the packages and it hasnt solved the issue.
> ionic-app-scripts.cmd build --target cordova --platform android
[23:25:18] ionic-app-scripts 3.2.4
[23:25:18] build dev started ...
[23:25:18] clean started ...
[23:25:18] clean finished in 21 ms
[23:25:18] copy started ...
[23:25:18] deeplinks started ...
[23:25:18] deeplinks finished in 515 ms
[23:25:18] transpile started ...
[23:25:25] transpile finished in 6.59 s
[23:25:25] preprocess started ...
[23:25:25] preprocess finished in less than 1 ms
[23:25:25] webpack started ...
[23:25:25] copy finished in 7.26 s
[23:25:30] webpack finished in 5.09 s
[23:25:30] sass started ...
[23:25:32] sass finished in 1.82 s
[23:25:32] postprocess started ...
[23:25:32] postprocess finished in 14 ms
[23:25:32] lint started ...
[23:25:32] build dev finished in 14.19 s
no-unused-variable is deprecated. Since TypeScript 2.9. Please use the built-in compiler checks instead.
[23:25:36] lint finished in 4.22 s
> cordova.cmd build android
Checking Java JDK and Android SDK versions
ANDROID_SDK_ROOT=undefined (recommended setting)
ANDROID_HOME=undefined (DEPRECATED)
Using Android SDK: C:\Users\IvanTzenev\AppData\Local\Android\sdk
Subproject Path: CordovaLib
Subproject Path: app
> Task :app:compileDebugJavaWithJavac FAILED
C:\GitHub\Accentis-Ionic\platforms\android\app\src\main\java\com\ionicframework\cordova\webview\IonicWebViewEngine.java:11: error: package android.support.annotation does not exist
import android.support.annotation.RequiresApi;
^
C:\GitHub\Accentis-Ionic\platforms\android\app\src\main\java\cordova\plugins\Diagnostic.java:57: error: cannot find symbol
import android.support.v4.app.ActivityCompat;
^
symbol: class ActivityCompat
location: package android.support.v4.app
C:\GitHub\Accentis-Ionic\platforms\android\app\src\main\java\cordova\plugins\Diagnostic_External_Storage.java:28: error: cannot find symbol
import android.support.v4.os.EnvironmentCompat;
^
symbol: class EnvironmentCompat
location: package android.support.v4.os
C:\GitHub\Accentis-Ionic\platforms\android\app\src\main\java\cordova\plugins\Diagnostic_Notifications.java:35: error: cannot find symbol
import android.support.v4.app.NotificationManagerCompat;
^
symbol: class NotificationManagerCompat
location: package android.support.v4.app
C:\GitHub\Accentis-Ionic\platforms\android\app\src\main\java\org\apache\cordova\camera\CameraLauncher.java:40: error: package android.support.v4.content does not exist
import android.support.v4.content.FileProvider;
^
C:\GitHub\Accentis-Ionic\platforms\android\app\src\main\java\org\apache\cordova\camera\CordovaUri.java:25: error: package android.support.v4.content does not exist
import android.support.v4.content.FileProvider;
^
C:\GitHub\Accentis-Ionic\platforms\android\app\src\main\java\org\apache\cordova\camera\FileProvider.java:21: error: package android.support.v4.content does not exist
public class FileProvider extends android.support.v4.content.FileProvider {}
^
C:\GitHub\Accentis-Ionic\platforms\android\app\src\main\java\com\ionicframework\cordova\webview\IonicWebViewEngine.java:137: error: cannot find symbol
#RequiresApi(Build.VERSION_CODES.LOLLIPOP)
^
symbol: class RequiresApi
location: class IonicWebViewEngine.ServerClient
C:\GitHub\Accentis-Ionic\platforms\android\app\src\main\java\cordova\plugins\Diagnostic.java:648: error: cannot find symbol
java.lang.reflect.Method method = ActivityCompat.class.getMethod("shouldShowRequestPermissionRationale", Activity.class, java.lang.String.class);
^
symbol: class ActivityCompat
location: class Diagnostic
C:\GitHub\Accentis-Ionic\platforms\android\app\src\main\java\cordova\plugins\Diagnostic_External_Storage.java:216: error: cannot find symbol
addPath = Environment.MEDIA_MOUNTED.equals(EnvironmentCompat.getStorageState(file));
^
symbol: variable EnvironmentCompat
location: class Diagnostic_External_Storage
C:\GitHub\Accentis-Ionic\platforms\android\app\src\main\java\cordova\plugins\Diagnostic_Notifications.java:123: error: cannot find symbol
NotificationManagerCompat notificationManagerCompat = NotificationManagerCompat.from(this.cordova.getActivity().getApplicationContext());
^
symbol: class NotificationManagerCompat
location: class Diagnostic_Notifications
C:\GitHub\Accentis-Ionic\platforms\android\app\src\main\java\cordova\plugins\Diagnostic_Notifications.java:123: error: cannot find symbol
NotificationManagerCompat notificationManagerCompat = NotificationManagerCompat.from(this.cordova.getActivity().getApplicationContext());
^
symbol: variable NotificationManagerCompat
location: class Diagnostic_Notifications
C:\GitHub\Accentis-Ionic\platforms\android\app\src\main\java\org\apache\cordova\camera\CameraLauncher.java:303: error: cannot find symbol
this.imageUri = new CordovaUri(FileProvider.getUriForFile(cordova.getActivity(),
^
symbol: method getUriForFile(Activity,String,File)
location: class FileProvider
C:\GitHub\Accentis-Ionic\platforms\android\app\src\main\java\org\apache\cordova\camera\CameraLauncher.java:801: error: cannot find symbol
Uri tmpFile = FileProvider.getUriForFile(cordova.getActivity(),
^
symbol: method getUriForFile(Activity,String,File)
location: class FileProvider
Note: Some input files use or override a deprecated API.
Note: Recompile with -Xlint:deprecation for details.
Note: Some input files use unchecked or unsafe operations.
Note: Recompile with -Xlint:unchecked for details.
14 errors
FAILURE: Build failed with an exception.
* What went wrong:
Execution failed for task ':app:compileDebugJavaWithJavac'.
> Compilation failed; see the compiler error output for details.
* Try:
Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output. Run with --scan to get full insights.
* Get more help at https://help.gradle.org
Deprecated Gradle features were used in this build, making it incompatible with Gradle 7.0.
Use '--warning-mode all' to show the individual deprecation warnings.
See https://docs.gradle.org/6.5/userguide/command_line_interface.html#sec:command_line_warnings
BUILD FAILED in 1s
21 actionable tasks: 1 executed, 20 up-to-date
Command failed with exit code 1: C:\GitHub\Accentis-Ionic\platforms\android\gradlew cdvBuildDebug -b C:\GitHub\Accentis-Ionic\platforms\android\build.gradle
[ERROR] An error occurred while running subprocess cordova.
cordova.cmd build android exited with exit code 1.
Re-running this command with the --verbose flag may provide more information.

i think you are missing these v4 libraries or dependencies are not getting sync properly. first thing you can invalidate/restart(file menu in Android studio) your project and if still not working then can check below link: package android.support.v4.app does not exist ; in Android studio 0.8

Error: Execution failed for task ':app:compileDebugJavaWithJavac'

I'm creating a React native project. But when I enter the npx react-native run-android command, I get the following error.
> Task :app:compileDebugJavaWithJavac FAILED
18 actionable tasks: 18 executed
/Users/Cans/Desktop/react-egitimi/introduction/loginPageProject/android/app/src/main/java/com/loginapp/MainApplication.java:19: error: cannot find symbol
return BuildConfig.DEBUG;
^
symbol: variable BuildConfig
Note: /Users/Cans/Desktop/react-egitimi/introduction/loginPageProject/android/app/src/debug/java/com/loginpageproject/ReactNativeFlipper.java uses or overrides a deprecated API.
Note: Recompile with -Xlint:deprecation for details.
1 error
FAILURE: Build failed with an exception.
* Get more help at https://help.gradle.org
BUİLD FAILED in 18s
error Failed to install the app. Make sure you have the Android development environment set up: https://reactnative.dev/docs/environment-setup.
Error: Command failed: ./gradlew app:installDebug -PreactNativeDevServerPort=8081
/Users/Cans/Desktop/react-egitimi/introduction/loginPageProject/android/app/src/main/java/com/loginapp/MainApplication.java:19: error: cannot find symbol
return BuildConfig.DEBUG;
^
symbol: variable BuildConfig
Note: /Users/Cans/Desktop/react-egitimi/introduction/loginPageProject/android/app/src/debug/java/com/loginpageproject/ReactNativeFlipper.java uses or overrides a deprecated API.
Note: Recompile with -Xlint:deprecation for details.
1 error
FAILURE: Build failed with an exception.
I tried deleting gradle but it gives the same result again. what is the solution?

react-native-config: cannot find symbol

I've got a fresh React Native app, where I'm trying to use react-native-config:
npx react-native init RNConfigDemo
cd RNConfigDemo
yarn add react-native-config
echo "SOME_VAR="something"" > .env
I tried to add a line in my ./android/app/src/main/java/com/rnconfigdemo/MainActivity.java:
...
return BuildConfig.SOME_VAR;
...
and I always get the following:
RNConfigDemo/android/app/src/main/java/com/rnconfigdemo/MainActivity.java:40: error: cannot find symbol
return BuildConfig.SOME_VAR;
^
symbol: variable SOME_VAR
location: class BuildConfig
Note: Some input files use or override a deprecated API.
Note: Recompile with -Xlint:deprecation for details.
1 error
FAILURE: Build failed with an exception
I can access non-.env defined BuildConfig, such as BuildConfig.DEBUG, with no issues. But my defined BuildConfig properties throw the above
I've tried running npx react-native link react-native-config, despite this having been autolinked, as well as the troubleshooting guidelines.
I verified the manually linked additions were present in their respective files.
I tried adding import com.facebook.react.BuildConfig, and then import com.rnconfigdemo.BuildConfig, to no avail.
I've followed all the steps for the Android build in the package's README
What's the issue here?

Jenkins Build Failed error: cannot find symbol

I have done my Automation in java using Junit and push that code to bitbucket and integrated it with jenkins. But when i am starting build after creating job it start failling and throwing some error. i am not able get that why it is not taking class path and how i can set class path to avoid this issue
Here is error coming on console
[javac] C:\Program Files\Jenkins\workspace\ABC-first-job\tst\com\cb\abc\ABCTest.java:110: error: cannot find symbol
[javac] Assert.assertTrue(response.contains(ABCConstant.DATA_MESSAGE));
[javac] ^
[javac] symbol: variable Assert
[javac] location: class ABCTest
[javac] 47 errors
BUILD FAILED
C:\Program Files\Jenkins\workspace\ABC-first-job\build.xml:48: Compile failed; see the compiler error output for details.
Total time: 2 seconds
Build step 'Invoke Ant' marked build as failure
Finished: FAILURE

Check if there was any recent jdk version updates for jdk used to build the code. If you have a slave node also check the jdk version on the same.