import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;
/**
* data:2018-6-22
* author:qixin
* descriptor:日期常用方法
* */
public class DateUtil {
private static SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd");
private static SimpleDateFormat dayFormat = new SimpleDateFormat("yyyy-MM-dd");
private static SimpleDateFormat weekFormat = new SimpleDateFormat("yyyy-ww");
private static SimpleDateFormat monthFormat = new SimpleDateFormat("yyyy-MM");
/**
* Turn date into week.
* @author yinfuyuan <[email protected]>
* @param day The date that needs to be converted into the week.
* @return The week corresponding to the date or empty string.
*/
public static String dayToWeek(String day) {
try {
Date date = dayFormat.parse(day);
Calendar calendar = Calendar.getInstance();
calendar.setTime(date);
calendar.setFirstDayOfWeek(Calendar.MONDAY);
String year = (new SimpleDateFormat("yyyy")).format(calendar.getTime());
String week = String.valueOf(calendar.get(Calendar.WEEK_OF_YEAR));
return year + "-" + week;
} catch (ParseException pe) {
return "";
}
}
/**
* Turn date into month.
* @author yinfuyuan <[email protected]>
* @param day The date that needs to be converted into the month.
* @return The month corresponding to the date or empty string.
*/
public static String dayToMonth(String day) {
try {
Date date = dayFormat.parse(day);
Calendar calendar = Calendar.getInstance();
calendar.setTime(date);
return monthFormat.format(calendar.getTime());
} catch (ParseException pe) {
return "";
}
}
/**
* Turn first day of the week into day.
* @author yinfuyuan <[email protected]>
* @param week The week that needs to be converted into a day.
* @return The day corresponding to first of the week or empty string.
*/
public static String weekToFirstDay(String week) {
try {
Date date = weekFormat.parse(week);
Calendar calendar = Calendar.getInstance();
calendar.setTime(date);
calendar.setFirstDayOfWeek(Calendar.MONDAY);
calendar.add(Calendar.DATE, 1);
return dayFormat.format(calendar.getTime());
} catch (ParseException pe) {
return "";
}
}
/**
* Turn last day of the week into day.
* @author yinfuyuan <[email protected]>
* @param week The week that needs to be converted into a day.
* @return The day corresponding to last day of the week or empty string.
*/
public static String weekToLastDay(String week) {
try {
Date date = weekFormat.parse(week);
Calendar calendar = Calendar.getInstance();
calendar.setTime(date);
calendar.add(Calendar.DATE, 7);
calendar.setFirstDayOfWeek(Calendar.MONDAY);
return dayFormat.format(calendar.getTime());
} catch (ParseException pe) {
return "";
}
}
/**
* Turn week into month.
* @author yinfuyuan <[email protected]>
* @param week The week that needs to be converted into a month.
* @return The month corresponding to the week or empty string.
*/
public static String weekToMonth(String week) {
try {
Date date = weekFormat.parse(week);
Calendar calendar = Calendar.getInstance();
calendar.setTime(date);
calendar.setFirstDayOfWeek(Calendar.MONDAY);
return monthFormat.format(calendar.getTime());
} catch (ParseException pe) {
return "";
}
}
/**
* Turn first day of the month into day.
* @author yinfuyuan <[email protected]>
* @param month The month that needs to be converted into a date.
* @return The first day of the month or empty string.
*/
public static String monthToFirstDay(String month) {
try {
Date date = monthFormat.parse(month);
Calendar calendar = Calendar.getInstance();
calendar.setTime(date);
return dayFormat.format(calendar.getTime());
} catch (ParseException pe) {
return "";
}
}
/**
* Turn last day of the month into day.
* @author yinfuyuan <[email protected]>
* @param month The month that needs to be converted into a date.
* @return The last day of the month or empty string.
*/
public static String monthToLastDay(String month) {
try {
Date date = monthFormat.parse(month);
Calendar calendar = Calendar.getInstance();
calendar.setTime(date);
calendar.add(Calendar.MONTH, 1);
calendar.add(Calendar.DATE, -1);
return dayFormat.format(calendar.getTime());
} catch (ParseException pe) {
return "";
}
}
/**
* Turn first week of the month into week.
* @author yinfuyuan <[email protected]>
* @param month The month that needs to be converted into a first week.
* @return The first week of the month corresponding to the week or empty string.
*/
public static String monthToFirstWeek(String month) {
try {
Date date = monthFormat.parse(month);
Calendar calendar = Calendar.getInstance();
calendar.setTime(date);
return weekFormat.format(calendar.getTime());
} catch (ParseException pe) {
return "";
}
}
/**
* Turn last week of the month into week.
* @author yinfuyuan <[email protected]>
* @param month The month that needs to be converted into a last week.
* @return The last week of the month corresponding to the week or empty string.
*/
public static String monthToLastWeek(String month) {
try {
Date date = monthFormat.parse(month);
Calendar calendar = Calendar.getInstance();
calendar.setTime(date);
calendar.add(Calendar.MONTH, 1);
calendar.add(Calendar.DATE, -1);
return weekFormat.format(calendar.getTime());
} catch (ParseException pe) {
return "";
}
}
/**
* 返回天数double类型
* @author qixin
* @param startTime,
* @param endTime,
* @return 返回天数double类型 天数小于1的都归为1（默认1天即汇总）
*/
public static Double getDayNum(String startTime,String endTime) {
SimpleDateFormat sdf=new SimpleDateFormat("yyyy-MM-dd");
Double dayNum=1.00d;
try{
Calendar cal = Calendar.getInstance();
cal.setTime(sdf.parse(startTime));
long time1 = cal.getTimeInMillis();
cal.setTime(sdf.parse(endTime));
long time2 = cal.getTimeInMillis();
long between_days=(time2-time1)/(1000*3600*24);
if (between_days>1){
String day=between_days+"";
dayNum=Double.valueOf(day);
}else {
dayNum=1.00d;
}
}catch (Exception e){
e.printStackTrace();
System.out.println(e.getMessage());
}
return dayNum;
}
}
感谢观看