Android 日期计算类

package com.utils.datecount;

import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.GregorianCalendar;

public class DateCount {

/**
* datelevel 0为7天内，1为7到15天，2为15天以上
*/
public static int datelevel = 0;
public static int positionweek = -1;
public static int position2week = -1;

/**
* 获取与今天时间差
* @param endTime
* @return
*/
public static double countDate(String startTime) {

Date curDate = new Date(System.currentTimeMillis());// 获取当前时间
SimpleDateFormat simpleDateFormat = new SimpleDateFormat("yyyy-MM-dd");// 输入日期的格式
Date date = null;
try {
date = simpleDateFormat.parse(startTime);
if (date == null) return 0;
} catch (java.text.ParseException e) {
return 0;
//				e.printStackTrace();
}
GregorianCalendar cal1 = new GregorianCalendar();
GregorianCalendar cal2 = new GregorianCalendar();
cal1.setTime(date);
cal2.setTime(curDate);
double dayCount = (cal2.getTimeInMillis() - cal1.getTimeInMillis()) / (1000 * 3600 * 24);// 从间隔毫秒变成间隔天数
return dayCount;
}
}

package com.utils.tools;

import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;

import android.text.TextUtils;
import android.text.format.DateFormat;

/**
* 日期格式化工具类
*
* @author Harryxu
*
*/
public class DateUtil {

public static Date convert2Date(String format, String dateStr) {
Date date = null;
try {
if (TextUtils.isEmpty(format)) format = "yyyy-MM-dd HH:mm:ss";
return new java.sql.Date(new SimpleDateFormat(format).parse(dateStr).getTime());
} catch (IllegalArgumentException e) {
e.printStackTrace();
} catch (Exception e) {
e.printStackTrace();
}
return date;
}

public static CharSequence formatDate(String format, String dateStr) {
Date date = null;
try {
date = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss").parse(dateStr);
} catch (IllegalArgumentException e) {
e.printStackTrace();
} catch (Exception e) {
e.printStackTrace();
}
if (date == null) date = new Date();
if (TextUtils.isEmpty(format)) format = "yyyy-MM-dd";
return DateFormat.format(format, date);
}

/**
* 根据偏量值取得传入时间的前后天数
*
* @param date
* @param offset 时间偏量值
* @return
*/
public static Date getNextPreDay(Date date, int offset) {
Calendar calendar = Calendar.getInstance();
calendar.setTime(date);
calendar.add(Calendar.DAY_OF_MONTH, offset);
date = calendar.getTime();
return date;
}

public static int getDays(Date date1, Date date2) {
Date kaishi = date1, jieshu = date2;
if (date1.compareTo(date2) > 0) {
kaishi = date2;
jieshu = date1;
}

long diff = jieshu.getTime() - kaishi.getTime();
float days = diff / 24f / 60 / 60 / 1000;
return (int) ((days - (int) days) >= 0 ? (days + 1) : days);
}

public static String addMinites( String time, int addminite){
SimpleDateFormat myFormatter = new SimpleDateFormat("HH:mm");
Calendar totime = Calendar.getInstance();
java.util.Date date = null;
try {
date = myFormatter.parse(time);
} catch (ParseException e) {
e.printStackTrace();
}
if (date == null) return null;
totime.setTime(date);
totime.add(Calendar.MINUTE, addminite);
date = totime.getTime();
return myFormatter.format(date);

}
}