I have to work on a test machine and when my work is complete and tested, I have to put it online for customers. On these two machines my code doesn't work in different ways! This part is the problem: public void setQntaRiduAsDecimalQuantityString(String qntaRidu) { try{ Double pippo=new Double(qntaRidu.replace(',','.')); } catch(NumberFormatException x) {...} On test machine i have String qntaRidu = 42,123 (with comma). All goes ok and pippo gets 42.123 On "Online" machine the same code, and same value in qntaRidu , cast a NumberFormatException. In java, is number format customizable ? (for example in Oracle you can localize your machine, so you can choose to have comma as decimal separator instead of dot.) Thanks for help (i work with oc4j 10.1.3.3)