关于date的一些用法

private static String DATE_TIME_FORMAT  = "yyyy-MM-dd HH:mm";

private static String DATE_FORMAT  = "yyyy-MM-dd";

private static String DATE_TIME_ONE  = " 09:00";

private static String DATE_TIME_TWO  = " 12:00";

private static String DATE_TIME_THREE  = " 13:00";

private static String DATE_TIME_FOUR  = " 18:00";

//取两个时间差
public String DatePool(String begin, String end) {
SimpleDateFormat strFormat = new SimpleDateFormat(DATE_TIME_FORMAT);
DateFormat format = new SimpleDateFormat(DATE_FORMAT);
Date start = null;
Date back = null;
try {
//先算出开始日有多少小时多少分
Date begTime = strFormat.parse(begin);
Date begDate1 = strFormat.parse(begDate+DATE_TIME_ONE);
Date begDate2 = strFormat.parse(begDate+DATE_TIME_TWO);
Date begDate3 = strFormat.parse(begDate+DATE_TIME_THREE);
Date begDate4 = strFormat.parse(begDate+DATE_TIME_FOUR);

if(begTime.getTime() <= begDate1.getTime()) {
begLong += begDate2.getTime()-begDate1.getTime();
begLong += begDate4.getTime()-begDate3.getTime();
}
if(begTime.getTime() > begDate1.getTime()
&& begTime.getTime() <= begDate2.getTime()) {
begLong += begDate2.getTime()-begTime.getTime();
begLong += begDate4.getTime()-begDate3.getTime();
}
if(begTime.getTime() > begDate2.getTime()
&& begTime.getTime() <= begDate3.getTime()) {
begLong += begDate4.getTime()-begDate3.getTime();
}
if(begTime.getTime() > begDate3.getTime()
&& begTime.getTime() <= begDate4.getTime()) {
begLong += begDate4.getTime()-begTime.getTime();
}

//再算出结束日有多少小时多少分
Date endTime = strFormat.parse(end);
Date endDate1 = strFormat.parse(endDate+DATE_TIME_ONE);
Date endDate2 = strFormat.parse(endDate+DATE_TIME_TWO);
Date endDate3 = strFormat.parse(endDate+DATE_TIME_THREE);
Date endDate4 = strFormat.parse(endDate+DATE_TIME_FOUR);
if(endTime.getTime() >= endDate1.getTime()
&& endTime.getTime() < endDate2.getTime()) {
endLong += endTime.getTime()-endDate1.getTime();
}
if(endTime.getTime() >= endDate2.getTime()
&& endTime.getTime() < endDate3.getTime()) {
endLong += endDate2.getTime()-endDate1.getTime();
}
if(endTime.getTime() >= endDate3.getTime()
&& endTime.getTime() < endDate4.getTime()) {
endLong += endTime.getTime()-endDate3.getTime();
endLong += endDate2.getTime()-endDate1.getTime();
}
if(endTime.getTime() >= endDate4.getTime()) {
endLong += endDate2.getTime()-endDate1.getTime();
endLong += endDate4.getTime()-endDate3.getTime();
}
Long min = ((endLong+begLong)/60/1000)%60;
Long hour = (((endLong+begLong)/60/1000) - min)/60;
//仅开始日和结束日有多少小时多少分
//System.out.println(hour+":"+min);

//然后算开始日和结束日相差多少天
Long day = (back.getTime()-start.getTime())/1000/3600/24-1;
//算出开始日和结束日中间有多少个星期后，还有没有多余的天数，就
Long days = day%7;
//算出开始日和结束日中间有多少个星期
Long weeks = (day - days)/7;
//算出开始日和结束日中间有多少个星期，减去星期六，星期天两天，有几个星期，就乘以2
Long daypool = day-weeks*2l;
Calendar calendar = Calendar.getInstance();
//这个是开始日的星期几calendar.get(Calendar.DAY_OF_WEEK)
calendar.setTime(start);
//System.out.println(calendar.get(Calendar.DAY_OF_WEEK));

Long xweek = 0l;
//现在要计算多余的天数中是否有星期六，星期天
int i = 0;
//星期天到星期六对应的数字是1到7，由于开始日到结束日相差的天数，
//没有包括开始日和结束日，所以相差天数的第一天就是开始日的对应的接下来的星期几
if(calendar.get(Calendar.DAY_OF_WEEK) == 7) {
i = 1;
} else {
i = calendar.get(Calendar.DAY_OF_WEEK) + 1;
}
for(int j = 0; j < days; j++) {
if(i==1 || i==7) {
xweek++;
}
//如果i==7说明到了星期六，则要从星期天开始，就是i=1
if(i == 7) {
i = 1;
} else {
i++;
}
}
return ((daypool-xweek)*8+hour)+":"+min;

} catch (ParseException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return null;
}