"Could not find tools.jar." error with react-native run-android

Is this a bug report?

Yes

Have you read the Contributing Guidelines?

Yes

Environment

Environment: OS: Windows 10 Node: 8.9.1 Yarn: 1.3.2 npm: 5.5.1 Watchman: Not Found Xcode: N/A Android Studio: Version 2.3.0.0 AI-162.4069837

Packages: (wanted => installed) react: 16.0.0 => 16.0.0 react-native: 0.50.3 => 0.50.3

Target Platform: Android

Steps to Reproduce

react-native init AwesomeProject cd AwesomeProject react-native run-android

Expected Behavior

The app is built and installed on my running VM.

Actual Behavior

I get this error: Could not find tools.jar. Please check that "C:\Program Files\Java\jre1.8.0_151" contains a valid JDK installation.

I had to set JAVA_HOME in my system environment variables to make it work. What happens is that in gradlew.bat RN checks for java.exe to test if it has found a valid JDK folder. But in my case it has found java.exe in a JRE folder which does not contain tools.jar.

Documentation should be updated on this page https://facebook.github.io/react-native/docs/getting-started.html and/or the error message should be improved adding “… or set JAVA_HOME to a valid one.”.

[Seunope]

I experience similar error when i was setting up react-native for window OS/Android. I followed the steps on how to setup reactive-native using the option that support the use of android studio emulator to display app https://facebook.github.io/react-native/docs/getting-started.html

In one of the steps I’m require to run this code choco install -y nodejs.install python2 jdk8

I got this error

Could not find tools.jar. Please check that “C:\Program Files\Java\jre1.8.0_151” contains a valid JDK installation.

Other packages (node.js & python) was successfully installed but JDK8 always fail to install. This was the fix that I used.

1. Ensure your internet connection is good.
2. run

choco install jdk8

Follow the instruction and JDK8 will be successfully install. Then you can run react-native init AwesomeProject cd AwesomeProject react-native run-android

[batuhantoma]

I’ve research a lot on this issue. working event for me : I removed Jdk, set it up again, and the problem is solved.