[Java] unmappable character for encoding MS950

In the command line:

javac -encoding utf-8 filename.java

Reference:

http://chshman310222.pixnet.net/blog/post/174134316-%5Bjava%5D-%E9%8C%AF%E8%AA%A4%E8%A7%A3%E6%B1%BA%3A-unmappable-character-for-encoding-ms950