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Could not find tools.jar. Please check that

On my system (Win 10, JRE 1.8.0, Android Studio 3.1.2, Gradle 4.1) there is no 
tools.jar in the JRE directory (C:Program FilesJavajre1.8.0_171).

However, I found it in C:Program FilesAndroidAndroid Studiojrelib and 
tried setting JAVA_HOME=C:Program FilesAndroidAndroid Studiojre

That works (for me)!

could not find tools.jar linux

on linux -> you need
1) to install openjdk :
sudo apt-get install openjdk-8-jdk
2) export jdk location : 
export JAVA_HOME=/usr/lib/jvm/java-8-openjdk-amd64

could not find tools jar

On my system (Win 10, JRE 1.8.0, Android Studio 3.1.2, Gradle 4.1) there is no tools.jar in the JRE directory (C:Program FilesJavajre1.8.0_171).

However, I found it in C:Program FilesAndroidAndroid Studiojrelib and tried setting JAVA_HOME=C:Program FilesAndroidAndroid Studiojre

could not find tools.jar mac

You should not alter gradle.properties manually. Try setting your 
JAVA_HOME in ~/.zshrc to something like-

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

then relaunch a terminal session