zzz@zzz-PC ~/AndroidStudioProjects/Example $ react-native run-android
Scanning 555 folders for symlinks in /home/zzz/AndroidStudioProjects/Example/node_modules (16ms)
Starting JS server...
Building and installing the app on the device (cd android && ./gradlew installDebug)...
ERROR: JAVA_HOME is set to an invalid directory: /usr/lib/jvm/java-9-oracle
Please set the JAVA_HOME variable in your environment to match the
location of your Java installation.
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/android-setup.html
Anyone can tell what's the problem, after I've run "react-native run-android" command. I've changed my JAVA_HOME path in /etc/environment, it still failed.
You need to be pointing to a jdk, currently you are pointing to a JVM. Go here and download the appropriate jdk and install it. Then switch your JAVA_HOME variable to the new path to the jdk.