How to config Tomcat to retrieve images from an external folder outside webapps(outside the context of tomcat)?

You should add following line in server.xml file

<Context path="/DataRepository" docBase="D:/DataRepository/" />

You must put this context tag inside of HOST tag.

Now you can just access the image present inside your path "D:/DataRepository/".

For Example if your DataRepository folder is having an image image 'sanket.jpg' then you can access it as ,

http://localhost:8080/DataRepository/sanket.jpg