Changes for:
Fix:
Use @RestController instead of @Controller to avoid exception:
javax.servlet.ServletException: Circular view path []: would dispatch to the current handler URL [/] again. Check your View...

learned from the following video

http://saurzcode.wordpress.com/2014/08/19/how-to-configure-swagger-to-generate-restful-api-doc-for-your-spring-boot-web-application/