Java Runtime Environment 188.8.131.52 (32-bit)
# OlsonData 2010i
* Java SE 6u21 contains Olson time zone data version 2010i.
# Additional Supported System Configurations
For Java SE 6u21, support has been added for the following system configurations:
* Oracle Enterprise Linux 5.5
* Oracle Enterprise Linux 5.4
* Oracle Enterprise Linux 4.8
* Red Hat Enterprise Linux 5.5
* Red Hat Enterprise Linux 5.4
* Oracle VM 184.108.40.206.0
* Google Chrome 4.0
# Support for Customized Loading Progress Indicators
* With Java SE 6u21, you can now enhance the loading experience of an application by providing a customized loading progress indicator (sometimes referred to as a progress bar) to better inform the end user of how much of the application has been downloaded during startup.
# Java Hotspot VM 17.0
* Java SE 6u21 includes version 17.0 of the Java HotSpot Virtual Machine with improvements to overall quality and features such as compressed object pointers, escape analysis-based optimization, code cache management, the Concurrent Mark-Sweep garbage collector and its successor, the Garbage First (G1) garbage collector. (G1 continues to be available in Early Access via the -XX:+UnlockExperimentalVMOptions -XX:+UseG1GC flag.
# Java VisualVM
Java VisualVM based on VisualVM 1.2.2 is included in Java SE 6u21. This release introduces the following features and enhancements:
* HeapWalker performance improvements
* VisualVM-Sampler performance improvements
* BTrace4VisualVM plugin introduces BTrace 1.1
* Profiling engine bugfixes
* Built on NetBeans Platform 6.8
# Security Exception Upon Drag-and-Drop
* Drag-and-drop would, under certain circumstances, result in a null value being passed instead of the expected data.
* Java SE 6u21 provides a fix that lets drag-and-drop operations succeed for signed applications or applications with the accessClipboard permission granted.
# Various Bug Fixes