To convert current time to utc format in samsung galaxy 5

I want to convert my current phone time to UTC format while posting a message.my code doesnt works in samsung galaxy 5.In samsung the current time is not converted.below is my开发者_如何学JAVA code

SimpleDateFormat sdfDateTime = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
sdfDateTime.setTimeZone(TimeZone.getTimeZone("UTC"));
String newtime = sdfDateTime.format(new Date(System.currentTimeMillis()));