Compared to other v6 release the release of Java SE 1.6.0_18 is definitely worthy of note.
Major changes
- VisualVM 1.2
- Performance improvements
- 20% faster jar file creation
- Java Hotspot VM 16.0
- Improved NUMA-aware allocation giving a 30% (for 32-bit) to 40% (for 64-bit) increase in performance (which is due also to arrive in jdk7 as well)
- Garbage collection improvements including new default java heap configuration in client and server vms
- Classloading optimisations for faster startup
- Code generation improvements including elision of needless conversions between integer primitive types and optimisations of common string concatenation patterns
- Garbage First (G1) garbage collector improved reliability and performance
- New options to request a heap dump or class histogram before or after a full GC
- Escape analysis based optimisation which appeared in 6u14 has been disabled in 6u18 to be restored in a future update
Minor changes
- Support for Windows 7
- JavaDB 10.5.3.0
- Application startup improvements
- Runtime performance improvements for UI applications
- Ability to read larger zip files of size up to 4GB
As the community eagerly awaits Java 7 in Q4 of 2010 releases such as this one serve to provide a little excitement in the mean time. It’s interesting to see that certain features that are due to arrive with Java 7 are also being offered in Java 6 such as NUMA-aware allocation, G1 collector and escape analysis. For whatever reason escape analysis has been disabled in this release but no reason has been given – it would be interesting to know why.
