java日期函数处理

Calendar cal = GregorianCalendar.getInstance();
cal.set(Calendar.YEAR, 2013);
cal.set(Calendar.MONTH, 2);
cal.set(Calendar.DAY_OF_MONTH, 28);
cal.add(Calendar.DATE,2);
String sqlDateStr=java.sql.Date.valueOf(String.valueOf(cal.get(Calendar.YEAR)+"-"+cal.get(Calendar.MONTH)+"-"+cal.get(Calendar.DAY_OF_MONTH))).toString();