====== Java Number Format ======
  * [[http://docs.oracle.com/javase/6/docs/api/java/text/NumberFormat.html|NumberFormat]] : NOT Thread Safe
  * [[http://docs.oracle.com/javase/6/docs/api/java/text/DecimalFormat.html|DecimalFormat]] : NOT Thread Safe

<code java>
NumberFormat nf = new DecimalFormat("#0.00");

NumberFormat nf = NumberFormat.getInstance();

</code>

  * ''#0.00'' : 0.00, 0.90, 10.92, 100.23 등의 형태

====== 쉼표대신 다른 문자로 자릿수 구분 ======
  * [[http://stackoverflow.com/questions/7452209/in-java-can-i-use-decimalformat-to-enter-a-dash-between-numbers|formatting - In Java, can I use DecimalFormat to enter a dash (-) between numbers?]]
  * [[https://docs.oracle.com/javase/8/docs/api/java/text/DecimalFormatSymbols.html|DecimalFormatSymbols]] : Thread Safe 인지 여부가 확실치 않음.
<code java>
DecimalFormatSymbols decimalFormatSymbols = new DecimalFormatSymbols();
decimalFormatSymbols.setGroupingSeparator('-');
DecimalFormat decimalFormat = new DecimalFormat("####,####", decimalFormatSymbols);

decimalFormat.format(123456789L); // 1-2345-6789
</code>