很实用的Android日期计算类

分享一个使用较方便的日期计算类：

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; 
 } 
} 

android日期格式化工具类：

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); 
   
 } 
} 

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持。