FULL PRODUCT VERSION :
java version "1.7.0_40"
Java(TM) SE Runtime Environment (build 1.7.0_40-b43)
Java HotSpot(TM) 64-Bit Server VM (build 24.0-b56, mixed mode)

ADDITIONAL OS VERSION INFORMATION :
Microsoft Windows Version 6.3.9600 (Windows 8.1)

EXTRA RELEVANT SYSTEM CONFIGURATION :
The user name and the user home folder contain non-ascii characters, such as ü

A DESCRIPTION OF THE PROBLEM :
NullPointerException at sun.awt.shell.Win32ShellFolder2$1.call

fileChooser.showOpenDialog(...) throws a NPE as shown above if the windows account and especially the windows user home folder contains non-ascii characters, such as ä,ö,ü. Looks like the non-ascii characters are not correctly interpreted, since they are translated to ? instead of ü and then the user home folder cannot be found and null is returned!

When changing the user to a user-account without non-ascii characters, no NPE is thrown!

As far as I know it was not working with prior Java releases, since I had the problem already in Java 6 and upgrading to Java 7 did not fix it.

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
System.out.println(System.getProperty("user.home"));

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
C:\Users\Günter
ACTUAL -
C:\Users\G?nter

ERROR MESSAGES/STACK TRACES THAT OCCUR :
NullPointerException at sun.awt.shell.Win32ShellFolder2$1.call

REPRODUCIBILITY :
This bug can be reproduced always.

---------- BEGIN SOURCE ----------
System.out.println(System.getProperty("user.home"));

JFileChooser fileChooser = new JFileChooser();
fileChooser.showOpenDialog(null);
---------- END SOURCE ----------

CUSTOMER SUBMITTED WORKAROUND :
The windows user home folder is not allowed to contain non-ascii characters in the folder name.