Resolution:
The default charset coding is retrieved by the JVM from the system OS settings. You can use the following Java code to get the default coding for charset:

String csn = Charset.defaultCharset().name();


To set the defaukt charset coding, change the locale for the OS, then the default charset coding will be changed accordingly.

For Windows:

User Locale Setting:

Windows 7 and Vista

1). Select Start -> Control Panel -> Region and Language (Regional and Language Options on Vista)
2). Open Formats tab
3). Select an item from the drop-down list

Windows XP

1). Select Start -> Control Panel -> Regional and Language Options
2). Open Regional Options tab
3). Select an item from the drop-down list

Windows 2000

1). Select Start -> Control Panel -> Regional Options
2). Open General tab
3). Select an item from the drop-down list

System Locale Setting:

When you change the system locale, you _must_ reboot your system; otherwise, you may see unexpected locale-setting behaviors.

Windows 7 and Vista

1). Select Start -> Control Panel -> Region and Language (Regional and Language Options on Vista)
2). Open Administrative tab
3). Click Change system locale... button
4). Select an item from the drop-down list
5). Reboot the system .

Windows XP

1). Select Start -> Control Panel -> Regional and Language Options
2). Open Advanced tab
3). Select an item from the drop-down list.
4). Reboot the system.

Windows 2000

1). Select Start -> Control Panel -> Regional Options
2). Open General tab
3). Click Set default... button
4). Select an item from the drop-down list
5). Reboot the system

For Mac OS-X 10.6 (Snow Leopard) the setting can be found here:

1). Open the System Preferences App
2). Click on "Language and Text" icon
3). The Language can be changed under the "Language" pane/tab
4). The User Locale setting can be changed under the "Formats" pane/tab

For older Mac versions:

User locale setting

1). Select System Preferences -> International
2). Open Formats tab
3). Select an item from the Region pop-up menu

UI language setting

1). Select System Preferences -> International
2). Open Language tab
3). Drag an item to the top of the Languages list

For Solaris/HP:

1). vi /etc/TIMEZONE
2). Edit LANG to LANG=de_AT.ISO8859-15 (or something like this)
3). Reboot

For Linux:

1). Edit ~/.bash_profile:
export LC_ALL=zh_CN (or something like this)
export LANG=zh_CN (or something like this)

2). Run locale to check
3). Re-login or reboot