public class Date{
public static void main(String[] args) {
SimpleDateFormat simpleDateFormat =new SimpleDateFormat("yyyyMMdd");
java.util.Date date = new java.util.Date();
String time = simpleDateFormat.format(date);
System.out.println("Today is " + time);
}
String str = "20030402";
Calendar ca=Calendar.getInstance();
int year=Integer.parseInt(str.substring(0,4));//年
ca.set(Calendar.YEAR,year);
int month=Integer.parseInt(str.substring(4,6));//月,注意要减1,因为一月对应的是0
ca.set(Calendar.MONTH,month-1);
int day=Integer.parseInt(str.substring(6,8));//日,
//如果想要得到第二天的日期就加1,如果超过了当月的最大天数,Calendar会自动处理
ca.set(Calendar.DAY_OF_MONTH,day);
Date date=ca.getTime();
System.out.println(date);