java - Adding Android jar files with relative path -

i'm trying add jar file existing app. when tried following absolute path build.gradle, works fine.

compile files('c:/users/julia/androidstudioprojects/testproject/libs/mypo.jar') 

however, when tried change relative path, doesn't work.

compile files('libs/mypo.jar'), tried compile project('libs:mypo.jar') compile project(':libs:mypo.jar') 

what's proper way add jar file app using relative path? thanks.

put jar file on app->lib folder , in project build.gradle use compile ('libs/filename.jar') sync project work