Different JDK Versions ?

Different JDK Versions ?

Java 1.1

* Language changes:
inner classes
* Library changes:
AWT event changes
JDBC, RMI
reflection

Java 1.2

* Language changes:
the strictfp keyword
* Library changes:
a unified collections system
Swing as a new UI-System on top of AWT
* Platform changes
a real JIT, greatly improving speed

Java 1.3

Mostly minor improvements:
* Platform changes:
HotSpot JVM: improvement over the original JIT

Java 1.4

JSR 59
* Language changes:
the assert keyword

* Library changes:
regular expressions support
NIO
integrated XML handling

Java 5 (a.k.a 1.5)

JSR 176, features and enhancements
* Language Changes:
generics (that's the big one)
annotations
enum types
varargs, enhanced for loops (for-each)
* Library changes:
concurrency utilities in java.util.concurrent

Java 6 (a.k.a 1.6)

JSR 270. features and enhancements
Mostly incremental improvements to existing libraries, no new language features (except for the @Override snafu).

Java 7 (a.k.a 1.7)

JSR 336, features and enhancements
* 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

Java 8 (a.k.a 1.8)

JSR 337, what's new
* Language changes:
lambda expressions (JSR 335, includes method handles)
continuation of Project Coin (small language improvements)
annotations on Java types
* Library changes:
Improved Date and Time API