You can know your current(default) encoding by running
System.getProperty("file.encoding")
and you can change default encoding with this property.
For Windows it is usually - cp1252
,
Long Story, queue from IBM KB:
Internally, the Java virtual machine (JVM) always operates with data
in Unicode. However, all data transferred into or out of the JVM is in
a format matching the file.encoding property. Data read into the JVM
is converted from file.encoding to Unicode and data sent out of the
JVM is converted from Unicode to file.encoding.