Calendar日历类 ：

package daysreplace;import com.sun.jdi.IntegerValue;import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Arrays;
import java.util.Calendar;
import java.util.Date;public class Test {public static void main(String[] args) throws ParseException {Calendar c = Calendar.getInstance();int year = c.get(Calendar.YEAR);int month = c.get(Calendar.MONTH);int day = c.get(Calendar.DATE);//获取月份 从0开始 需要+1System.out.println(year + "年" + (month + 1) + "月" + day + "日");}
}

package daysreplace;import com.sun.jdi.IntegerValue;import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Arrays;
import java.util.Calendar;
import java.util.Date;public class Test {public static void main(String[] args) throws ParseException {Calendar c = Calendar.getInstance();//加10年c.add(Calendar.YEAR,10);int year = c.get(Calendar.YEAR);int month = c.get(Calendar.MONTH);int day = c.get(Calendar.DATE);//获取月份 从0开始 需要+1System.out.println(year + "年" + (month + 1) + "月" + day + "日");}
}

 小案例：二月有多少天？

package daysreplace;import com.sun.jdi.IntegerValue;import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Arrays;
import java.util.Calendar;
import java.util.Date;
import java.util.Scanner;public class Test {public static void main(String[] args) throws ParseException {System.out.println("请输入年份");Scanner sc = new Scanner(System.in);int year = sc.nextInt();Calendar c = Calendar.getInstance();c.set(year,2,1);c.add(Calendar.DATE,-1);System.out.println(year+"年的二月有"+c.get(Calendar.DATE)+"天");}
}