In general, most shell command Windows, such as Python, Scala, some non-relational databases, etc., can be logged out by CTRL + D or CTRL + Z, CTRL + C, which is the most effective method.
If you don’t use the above mandatory exit command, you can also use Quit, exit, etc. However, when I use scala2.12 version, I find that Quit, exit, and Q are all difficult to make. After looking up the data, it can be seen that it is new
Version Scala’s exit command needs to be preceded by a ‘:’, i.e. : Q, : Quit, or sys.exit.
Original: http://www.cnblogs.com/mszw/p/6931696.html
If you don’t use the above mandatory exit command, you can also use Quit, exit, etc. However, when I use scala2.12 version, I find that Quit, exit, and Q are all difficult to make. After looking up the data, it can be seen that it is new
Version Scala’s exit command needs to be preceded by a ‘:’, i.e. : Q, : Quit, or sys.exit.
Original: http://www.cnblogs.com/mszw/p/6931696.html
this error is that jar jar dependency conflicts need to remove duplicate dependencies
locate the version to be deleted 
locate the jar location of the specific class 
in the pom file