info Starting JS server...
info Building and installing the app on the device (cd android && gradlew.bat app:installDebug)...

ERROR: JAVA_HOME is set to an invalid directory: ‪D:\Java\jdk1.8.0_121

Please set the JAVA_HOME variable in your environment to match the
location of your Java installation.
error 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
error Command failed: gradlew.bat app:installDebug

win10系统，按照文档来的