Jdk version automatically resets to 1.7 in android studio

Question

I installed Android Studio and i have both Jdk 1.7 as well as 1.8. When I executed the app , it gave me an error that it needs to be run with Jdk 1.8.I wen to File>> project structure and changed the path for jdk versio to jdk 1.8 but when I click OK the gradle sync starts with jdk 1.7 . Now when I open the project structure again, JDk version is reset to 1.7 again.

My JAVA_HOME system variable is set to the jdk 1.8 path. I uninstalled the Android Studio and reinstalled it, but nothing worked.

Answer 1

In your build.gradle also include the compileOptions tag to force JDK 1.8.

You will need to enable the Jack compiler as well to take advantage of Java 8 features.

android {
  ...
  defaultConfig {
    ...
    jackOptions {
      enabled true
    }
  }
  compileOptions {
    sourceCompatibility JavaVersion.VERSION_1_8
    targetCompatibility JavaVersion.VERSION_1_8
  }
}

See Google's page on Java 8 features available on Android here: https://developer.android.com/preview/j8-jack.html

Also, keep in mind that certain features are not support under Java 8 with the Jack compiler. One of the biggest (for me at least) is the Transform API with annotation processors. If you or a library you like uses the Transform API, you can disable Jack, and use a library to get some Java 8 features anyway, like Retrolambda.

See here for details on RetroLambda: https://github.com/evant/gradle-retrolambda