Issues and limitations on Windows

Known issues or limitations that you might encounter in specific Windows system environments, or configurations.

IPv6 support on Windows XP and Windows 2003

Version 7 introduced a new NIO.2 application programming interface (API) for asynchronous input/output (IO). However, sockets created with the NIO.2 APIs support only IPv4 network interfaces on the Windows XP and Windows 2003 platforms. The IBM® implementation of NIO.2 is consistent with this behavior.

Although sockets created with the earlier IBM NIO APIs or java.net can support either IPv4 or IPv6 network interfaces on Windows 2003 and Windows XP, this capability is deprecated in Version 7 and no longer supported in this release.

Unicode Shift_JIS code page alias
Note: This limitation applies to Japanese users only.
The Unicode code page alias "\u30b7\u30d5\u30c8\u7b26\u53f7\u5316\u8868\u73fe" for Shift_JIS has been removed. If you use this code page in your applications, replace it with Shift_JIS.

Font problems in supported locales
This version supports the following locales:
  • Bengali (bn_IN)
  • Malayalam (ml_IN)
  • Oriya (or_IN)
However, the fonts from these locales might not work on AWT components.

Use of sockets with IPv6

The 64-bit SDK supports IPv6. However, because the current IPv6 support in Windows is not dual-stack, the release emulates dual-stack behavior on an IPv6 enabled system. The emulation means that your application might use up to twice as many sockets.

To disable the emulation, disable IPv6 support by setting the system property java.net.preferIPv4Stack to true.

Input Method Editor (IME)

When working with an Input Method Editor (IME), before using the workspace for any other operation ensure that you complete the character composition and select the candidate.

If a user types text in an AWT TextArea while using an Input Method Editor (IME), then resizes the application window before committing the text, the text is committed automatically.

DBCS characters

If you are typing DBCS characters in a JTextArea, JTextField, or JFileChooser, switching from some Chinese IMEs (in particular, Chinese Internal Code and Zhengma) to Intelligent ABC IME might cause a core dump to be produced.

BIOS settings on AMD64 SMP systems

The Node memory interleaving BIOS setting must be set to DISABLED. Otherwise, unpredictable results might occur, including application crashes and hangs. This instruction is in accordance with recommendations from AMD.

Inconsistent timers on multicore or multiprocessor systems

On some multicore or multiprocessor systems, System.nanoTime() might not increase monotonically. Alternatively, System.nanoTime() might exhibit unexpectedly large time jumps. This behavior might be caused by a limitation in the Windows function QueryPerformanceCounter(). For more information, see Microsoft Knowledge Base article: Programs that use the QueryPerformanceCounter function may perform poorly.