In my android studio project want to use existing java project code
I tried this way:
Click File > New Module. Select Java Library and click Next.>
A simple google search gives you everything: https://www.google.co.za/search?q=import%20project%20to%20android%20studio
To import a project to Android Studio:
- Start Android Studio and close any open Android Studio projects.
- From the Android Studio menu select File > New > Import Project. ...
- Select the Eclipse ADT project folder with the AndroidManifest.xml file and click Ok.
- Select the destination folder and click Next.
Google has made this tutorial: https://developer.android.com/sdk/installing/migrate.html
I have had issues before with this so I normally just create a new project and just copy all the classes, drawables, etc from the old project into the new project.