6
votes

Could not find the "expo" package in your project when configuring the packager Starting JS server... Building and installing the app on the device (cd android && ./gradlew installDebug)...

Task :app:compileDebugJavaWithJavac FAILED /media/rahul/OTHER FILES/mob/first/android/app/src/main/java/com/practice/MainApplication.java:5: error: cannot find symbol import com.facebook.react.ReactApplication; ^ symbol: class ReactApplication location: package com.facebook.react /media/rahul/OTHER FILES/mob/first/android/app/src/main/java/com/practice/MainApplication.java:6: error: cannot find symbol import com.facebook.react.ReactNativeHost; ^ symbol: class ReactNativeHost location: package com.facebook.react /media/rahul/OTHER FILES/mob/first/android/app/src/main/java/com/practice/MainApplication.java:14: error: cannot find symbol public class MainApplication extends Application implements ReactApplication { ^ symbol: class ReactApplication /media/rahul/OTHER FILES/mob/first/android/app/src/main/java/com/practice/MainApplication.java:16: error: cannot find symbol private final ReactNativeHost mReactNativeHost = new ReactNativeHost(this) { ^ symbol: class ReactNativeHost location: class MainApplication /media/rahul/OTHER FILES/mob/first/android/app/src/main/java/com/practice/MainApplication.java:36: error: cannot find symbol public ReactNativeHost getReactNativeHost() { ^ symbol: class ReactNativeHost location: class MainApplication /media/rahul/OTHER FILES/mob/first/android/app/src/main/java/com/practice/MainActivity.java:5: error: MainActivity is not abstract and does not override abstract method getPackages() in ReactActivity public class MainActivity extends ReactActivity { ^ /media/rahul/OTHER FILES/mob/first/android/app/src/main/java/com/practice/MainApplication.java:16: error: cannot find symbol private final ReactNativeHost mReactNativeHost = new ReactNativeHost(this) { ^ symbol: class ReactNativeHost location: class MainApplication /media/rahul/OTHER FILES/mob/first/android/app/src/main/java/com/practice/MainApplication.java:35: error: method does not override or implement a method from a supertype @Override ^ 8 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

BUILD FAILED in 22s 15 actionable tasks: 14 executed, 1 up-to-date Could not install the app on the device, read the error above for details. Make sure you have an Android emulator running or a device connected and have set up your Android development environment: https://facebook.github.io/react-native/docs/getting-started.html

i am setting up react-native project for first time please check if i am following steps correctly? 1. create-react-native-app first 2. npm run eject 3. opening android studio and then simulator 4. react-native run-android but getting error as above.

6
So, scroll up to see more details. Or run it with one of those flags like it recommends - Kai

6 Answers

15
votes

This error occur because you RN version is different from Android's build.gradle version. When you create a react-native app probably it create android app like:

android/app/build.gradle

implementation "com.facebook.react:react-native:+"

So, inspect you node_modules folder, look for react-native folder and look for a folder with a number, that numbers are react-native version. For me it's 0.58.3 then update android/app/build.gradle:

implementation "com.facebook.react:react-native:0.58.3"

It's All.

4
votes

You should provide more info. The error you've posted is not very helpful.

Without more info, you could try to:

cd android && ./gradlew clean

and see if it helps.

1
votes

This happens to me because I forget to install some modules.

And I run:

1. npm install

2. npx react-native run-android

OBS: you can run npx react-native link too. To link your modules.

1
votes

I also had a similar crash report. But in my case the issue was a missing environment variable for JAVA_HOME. I set it to the same path as in Android Studio and that fixed the issue: File -> Project Structure -> SDK Location -> JDK location.

export JAVA_HOME="/Applications/Android Studio.app/Contents/jre/jdk/Contents/Home"
0
votes

[For people who are brought here by Google]

In my case, the error appeared after I try to link @react-native-async-storage/async-storage using react-native link.

I initialized my project using React Native CLI, which was a few minor versions behind. But I linked the dependency with npx react-native link. Version Mismatch!

To the best of my knowledge, this is the root cause of that error.

You are most likely to make changes inside android/app/src/main/java/com/focustime/MainApplication.java and android/settings.gradle. If you are developing with git, simply checkout those two files.

Following are the changes that RN link introduced:

diff --git a/android/app/src/main/java/com/focustime/MainApplication.java b/android/app/src/main/java/com/focustime/MainApplication.java
index ed18f44..2bdc42c 100644
--- a/android/app/src/main/java/com/focustime/MainApplication.java
+++ b/android/app/src/main/java/com/focustime/MainApplication.java
@@ -4,6 +4,7 @@ import android.app.Application;
 import android.content.Context;
 import com.facebook.react.PackageList;
 import com.facebook.react.ReactApplication;
+import com.reactnativecommunity.asyncstorage.AsyncStoragePackage;
 import com.facebook.react.ReactInstanceManager;
 import com.facebook.react.ReactNativeHost;
 import com.facebook.react.ReactPackage;
diff --git a/android/settings.gradle b/android/settings.gradle
index 20ccd07..f6f51cd 100644
--- a/android/settings.gradle
+++ b/android/settings.gradle
@@ -1,3 +1,5 @@
 rootProject.name = 'FocusTime'
+include ':@react-native-async-storage_async-storage'
+project(':@react-native-async-storage_async-storage').projectDir = new File(rootProject.projectDir, '../node_modules/@react-native-async-storage/async-storage/android')
 apply from: file("../node_modules/@react-native-community/cli-platform-android/native_modules.gradle"); applyNativeModulesSettingsGradle(settings)
 include ':app'
0
votes

For what it's worth, I ended here googling my similar compile problem and the issue was that an OS update had wiped Java JDK from my path. Fixing that solved the issue.