java 4捨五入

http://bioankeyang.blogspot.tw/2014/03/jjava.html


java 編碼問題
https://wefollownews.appspot.com/cittopnews201408_80/14080.html


http://magiclen.org/java-base64



印出unicode number

http://stackoverflow.com/questions/2220366/get-unicode-value-of-a-character

System.out.println( "\\u" + Integer.toHexString('÷' | 0x10000).substring(1) );