Language changes:
-Project Coin (small changes)
-switch on Strings
-try-with-resources
-diamond operator
Library changes:
-new abstracted file-system API (NIO.2) (with support for virtual filesystems)
-improved concurrency libraries
-elliptic curve encryption
-more incremental upgrades
Platform changes:
-support for dynamic languages
Below is the link explaining the newly added features of JAVA 7 , the explanation is crystal clear with the possible small examples for each features :