Java Convert string , double , int, long, Calendear

Java Convert string , double , int

Convert String to double
double doubleToString= Double.parseDouble(aString);

Convert String to int
int intToString= Integer.parseInt(aString);

Convert int to String
String aString = Integer.toString( intToString ); // or
aString = "" + intToString;


Convert milliseconds/ long to date format in Calendear    
Calendar calendar = Calendar.getInstance();
long milliSeconds = 86400000;
calendar.setTimeInMillis(milliSeconds);