如何格式化日期?风格化日期 - 黑马程序员技术交流社区

package date;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;
/**
* @author 小媛 <br>
* ①月份所填的值要比实际值小1. 所以参数-1<br>
* ②星期要比实际值大1. 所以参数+1<br>
*/
public class Demo_Date {
public static void main(String[] args) {
//需要什么方法从下面调取验证
}
/**
* 获取两个时间之间的间隔天数yi
*
* @param start
* @param end
* @return
*/
public static int getIntervalTimes(Date start, Date end) {
if (start.after(end)) {
Date date = start;
start = end;
end = date;
}
long startTimes = start.getTime();
long endTimes = end.getTime();
long intervalTimes = startTimes - endTimes;
return (int) (intervalTimes / (1000 * 60 * 60 * 24));
}
/**
* 获取两个时间之间的间隔天数
*
* @param start
* @param end
* @return
*/
public static int getIntervalTimes(Calendar start, Calendar end) {
if (start.after(end)) {
Calendar temp = start;
start = end;
end = temp;
}
long startTimes = start.getTimeInMillis();
long endTimes = start.getTimeInMillis();
long intervalTimes = startTimes - endTimes;
return (int) (intervalTimes / (1000 * 60 * 60 * 24));
}
/**
* 获取某年某月某日，在添加了×天之后，又回到本月的第几天
*
* @param year
* @param mouth
* @param date
* @param addDate
*/
private static String getDateWithAddAtMouth(int year, int mouth, int date, int addDate) {
SimpleDateFormat simpleDateFormat = new SimpleDateFormat("yyyy-MM-dd");
Calendar calendar = Calendar.getInstance();
calendar.set(Calendar.YEAR, year);
calendar.set(Calendar.MONTH, mouth - 1);
calendar.set(Calendar.DAY_OF_MONTH, date);
calendar.roll(Calendar.DATE, addDate);
Date time = calendar.getTime();
return simpleDateFormat.format(time);
}
/**
* 计算某年某月某日的基础上添加×天
*
* @param year
* @param mouth
* @param day
* @param addDay
*/
private static String getDateWithAdd(int year, int mouth, int day, int addDay) {
SimpleDateFormat simpleDateFormat = new SimpleDateFormat("yyyy-MM-dd");
Calendar calendar = Calendar.getInstance();
calendar.set(Calendar.YEAR, year);
calendar.set(Calendar.MONTH, mouth - 1);
calendar.set(Calendar.DAY_OF_MONTH, day);
calendar.add(Calendar.DATE, addDay);
Date time = calendar.getTime();
return simpleDateFormat.format(time);
}
/**
* 获取某年的第几个星期几，是×年×月×日
*
* @param year
* @param noWeekOfYear
* @param noDayOfWeek
*/
private static String getNoWeekIsNoDay(int year, int noWeekOfYear, int noDayOfWeek) {
SimpleDateFormat simpleDateFormat = new SimpleDateFormat("yyyy-MM-dd");
Calendar calendar = Calendar.getInstance();
calendar.set(Calendar.YEAR, year);
calendar.set(Calendar.WEEK_OF_YEAR, noWeekOfYear);
calendar.set(Calendar.DAY_OF_WEEK, noDayOfWeek);
return simpleDateFormat.format(calendar.getTime());
}
/**
* 获取某年某月某日，是一年中的第几个星期
*
* @param year
* @param mouth
* @param day
*/
private static int getDayAtYearByNoWeek(int year, int mouth, int day) {
Calendar calendar = Calendar.getInstance();
calendar.set(Calendar.YEAR, year);
calendar.set(Calendar.MONTH, mouth - 1);
calendar.set(Calendar.DAY_OF_MONTH, day);
int weekNo = calendar.get(Calendar.WEEK_OF_YEAR);
return weekNo;
}
/**
* 格式化输出转换日期格式
*/
private static String Date4Format() {
Date date = new Date();
SimpleDateFormat fm = new SimpleDateFormat("yyyy-MM-dd hh:mm:ss");
return fm.format(date);
}
/**
* Date转换成 Calendar格式
*/
private static void Date4Calendar() {
Date date = new Date();
Calendar time = Calendar.getInstance();
time.setTime(date);
System.out.println(date);
}
/**
* 获取一个月的最大天数
*/
private static void getMonthMaxDay() {
Calendar time = Calendar.getInstance();
time.clear();
time.set(Calendar.YEAR, 2015);
time.set(Calendar.MONTH, 7 - 1);
int day = time.getActualMaximum(Calendar.DAY_OF_MONTH);
System.out.println(day);
}
}

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