JDK 主要版本更新总结

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

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 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 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 1.4

JSR 59

Language changes:

the assert keyword
Library changes:

regular expressions support
NIO
integrated XML handling

Java 1.3

Mostly minor improvements, really.

Platform changes:

HotSpot JVM: improvement over the original JIT

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 1.1

Language changes:

inner classes
Library changes:

AWT event changes
JDBC, RMI
reflection
Java 1.0

参考：
https://en.wikipedia.org/wiki/Java_version_history