Java - Convert String to Date

DateFormat formatter = new SimpleDateFormat("yyyyMMdd");
String ddMMyyyy = "20130128";
Date date = null;

date = (Date) formatter.parse(ddMMyyyy);

Or

DateFormat formatter = new SimpleDateFormat("yyyy-MM-dd");
String dd_MM_yyyy = "2013-01-28";
Date date = null;

date = (Date) formatter.parse(dd_MM_yyyy);

Java - Convert String to int

int i = null;
String s = "12345";

i = Integer.parseInt(s);

Java - Convert int to String

int i = 3;
String s = "";

s = Integer.toString(i); 

or

s = String.valueOf(i);