error: package com.android.annotations does not exist

Question

I have the following class

import com.android.annotations.NonNullByDefault;

@NonNullByDefault
public final class Log {
    ...
}

and here

Answer 1

To automatically fix all android to androidx issues for React Native (prerequisite npx)

Add the following two flags to true in your gradle.properties file at ProjectFolder/android/gradle.properties

android.useAndroidX=true
android.enableJetifier=true

Execute

npm install --save-dev jetifier
npx jetify
npx react-native run-android

In your package.json add the following to scripts

  "postinstall" : "npx jetify"

More info at https://github.com/mikehardy/jetifier

Update: This is now in-built in react-native 0.60. If you migrate to react-native 0.60 you won't need this step. - https://facebook.github.io/react-native/blog/2019/07/03/version-60#androidx-support