Upper First letter After _

Upper First letter After _

public String treat(String str){

		  final Pattern pattern = Pattern.compile("([^_.]*)[_]*");
	        Matcher matcher = pattern.matcher(str);
	        String ret  ="";
	        while(matcher.find()){
	        	if(!matcher.group(1).equals(""))
	        		ret += upperFirstCharacter(matcher.group(1));
	        }
	        return ret;
	}
	private String upperFirstCharacter(String pattern){
		return pattern.replaceFirst(String.valueOf(pattern.charAt(0)), String.valueOf((char) (((int) pattern.charAt(0)) - 32)));
	}