日期運算加減年月日

package net.street.common.util;

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

public class DateTimeUtils {
 
 private static long MILLIS_ONE_DATE = 1000 * 3600 * 24;

 public DateTimeUtils() {
  super();
 }

 public static String format(long millis, String pattern) {
  return format(new Date(millis), pattern, null);
 }

 public static String format(Date date, String pattern) {
  return format(date, pattern, null);
 }

 public static String format(long millis, String pattern, Locale locale) {
  return format(new Date(millis), pattern, locale);
 }

  public static String format(Date date, String pattern, Locale locale) {
  if (locale == null)
   locale = Locale.getDefault();
  SimpleDateFormat df = new SimpleDateFormat(pattern, locale);
  return df.format(date);
 }

 /**
  * 將格式格式化成日期
  * 
  * @param value
  * @param pattern
  *            yyyy-MM-dd,yyyy-MM-dd hh:mm:ss
  * @return
  */
 public static Date parse(String value, String pattern) {
  if (value == null)
   return null;
  try {
   return new SimpleDateFormat(pattern).parse(value);
  } catch (ParseException e) {
   throw new RuntimeException("The symbol " + value + "with format "
     + pattern + " can't be converted to a Date", e);
  }
 }

 public static Date now() {
  return new Date();
 }

 /**
  * 兩個日期的相差天數
  */
 public static int getDiffDays(Date date1, Date date2) {
  Calendar c = Calendar.getInstance();
  c.setTime(date1);
  long time1 = c.getTimeInMillis();

  c.setTime(date2);
  long time2 = c.getTimeInMillis();
  long between_days = (time2 - time1) / MILLIS_ONE_DATE;

  return Integer.parseInt(String.valueOf(between_days));

 }

 /**
  * 兩個日期的相差月數
  * 
  * @param date1
  * @param date2
  * @return
  */
 public static int getDiffMonths(Date date1, Date date2) {
  Calendar c1 = Calendar.getInstance();
  Calendar c2 = Calendar.getInstance();
  c1.setTime(date1);
  if (date2 == null) {
   c2.setTime(new java.util.Date());
  } else {
   c2.setTime(date2);
  }
  int year1 = c1.get(Calendar.YEAR);
  int year2 = c2.get(Calendar.YEAR);
  int month1 = c1.get(Calendar.MONTH);
  int month2 = c2.get(Calendar.MONTH);

  return (year2 - year1) * 12 + (month2 - month1) + 1;
 }

 /**
  * 計算兩個日期的相差年數
  */
 public static int getDiffYears(Date date1, Date date2) {
  Calendar c1 = Calendar.getInstance();
  Calendar c2 = Calendar.getInstance();
  c1.setTime(date1);
  if (date2 == null) {
   c2.setTime(new java.util.Date());
  } else {
   c2.setTime(date2);
  }
  int year1 = c1.get(Calendar.YEAR);
  int year2 = c2.get(Calendar.YEAR);

  return year2 - year1 + 1;
 }

 /**
  * 計算兩個日期的相差多少年多少月
  */
 public static String getDiffYearsAndMonths(Date date1, Date date2) {
  if (!check(date1, date2)) {

  }

  String yearmonthStr = "";
  Calendar c1 = Calendar.getInstance();
  Calendar c2 = Calendar.getInstance();

  c1.setTime(date1);
  if (date2 == null) {
   c2.setTime(new java.util.Date());
  } else {
   c2.setTime(date2);
  }

  int year1 = c1.get(Calendar.YEAR);
  int year2 = c2.get(Calendar.YEAR);
  int month1 = c1.get(Calendar.MONTH);
  int month2 = c2.get(Calendar.MONTH);

  int yearmonth = (year2 - year1) * 12 + (month2 - month1) + 1;
  int year = yearmonth / 12;
  int month = yearmonth % 12;

  if (year > 0) {
   yearmonthStr = year + "年";
  }
  if (month > 0) {
   yearmonthStr = yearmonthStr + month + "個月";
  }
  return yearmonthStr;
 }

 private static boolean check(Date date1, Date date2) {
  if (date1 == null || date2 == null) {
   return false;

  }
  if (date1.after(date2)) {
   return false;
  }
  return true;

 }
 
 /**
  * 獲得指定日期上個月的日期
  * 
  * @return
  */
 public static Date getPreviousMonthDate(Date appointDate) {
  Calendar appointCalendar = Calendar.getInstance();
  appointCalendar.setTime(appointDate);
  Calendar lastDate = Calendar.getInstance();
  lastDate.set(Calendar.DATE, appointCalendar.get(Calendar.DATE));// 
  lastDate.set(Calendar.MONTH, appointCalendar.get(Calendar.MONTH)-1);
  lastDate.set(Calendar.YEAR, appointCalendar.get(Calendar.YEAR));
  return lastDate.getTime();
 }
 
 /**
  * 獲得指定日期下個月的日期
  * 
  * @return
  */
 public static Date getNextMonthDate(Date appointDate) {
  Calendar appointCalendar = Calendar.getInstance();
  appointCalendar.setTime(appointDate);
  Calendar lastDate = Calendar.getInstance();
  lastDate.set(Calendar.DATE, appointCalendar.get(Calendar.DATE));// 
  lastDate.set(Calendar.MONTH, appointCalendar.get(Calendar.MONTH)+1);
  lastDate.set(Calendar.YEAR, appointCalendar.get(Calendar.YEAR));
  return lastDate.getTime();
 }
 
 /**
  * 獲得指定日期第一天的日期
  * 
  * @return
  */
 public static Date getMonthFirst(Date appointDate) {
  Calendar appointCalendar = Calendar.getInstance();
  appointCalendar.setTime(appointDate);
  Calendar lastDate = Calendar.getInstance();
  lastDate.set(Calendar.DATE, 1);// 
  lastDate.set(Calendar.MONTH, appointCalendar.get(Calendar.MONTH));
  lastDate.set(Calendar.YEAR, appointCalendar.get(Calendar.YEAR));
  return lastDate.getTime();
 }
 
 /**
  * 獲得指定日期最後一天的日期
  * 
  * @return
  */
 public static Date getMonthEnd(Date appointDate) {
  Calendar appointCalendar = Calendar.getInstance();
  appointCalendar.setTime(appointDate);
  Calendar lastDate = Calendar.getInstance();
  lastDate.set(Calendar.DATE, 1);// 減一個月
  lastDate.set(Calendar.MONTH, appointCalendar.get(Calendar.MONTH)+1);// 減一個月
  lastDate.set(Calendar.YEAR, appointCalendar.get(Calendar.YEAR));// 把日期設置爲當月第一天
  lastDate.add(Calendar.DATE, -1);
  return lastDate.getTime();
 }

 /**
  * 獲得指定日期的上月第一天的日期
  * 
  * @return
  */
 public static Date getPreviousMonthFirst(Date appointDate) {
  Calendar appointCalendar = Calendar.getInstance();
  appointCalendar.setTime(appointDate);
  Calendar lastDate = Calendar.getInstance();
  lastDate.set(Calendar.DATE, 1);// 
  lastDate.set(Calendar.MONTH, appointCalendar.get(Calendar.MONTH)-1);
  lastDate.set(Calendar.YEAR, appointCalendar.get(Calendar.YEAR));
  return lastDate.getTime();
 }
 
 /**
  * 獲得指定日期的上月最後一天的日期
  * 
  * @return
  */
 public static Date getPreviousMonthEnd(Date appointDate) {
  Calendar appointCalendar = Calendar.getInstance();
  appointCalendar.setTime(appointDate);
  Calendar lastDate = Calendar.getInstance();
  lastDate.set(Calendar.DATE, 1);// 減一個月
  lastDate.set(Calendar.MONTH, appointCalendar.get(Calendar.MONTH));// 減一個月
  lastDate.set(Calendar.YEAR, appointCalendar.get(Calendar.YEAR));// 把日期設置爲當月第一天
  lastDate.add(Calendar.DATE, -1);
  return lastDate.getTime();
 }

 /**
  * 獲得指定日期的指定類型(年/月/日)間隔日期<br/>
  * 如：指定日期2年後的日期,15個月後的日期,35天后的日期
  * @param appointDate
  * 
  * @param type
  *    共三種類型年、月、日(Calendar.YEAR/Calendar.MONTH/Calendar.DATE)
  * @param number
  *    如果是負數則爲向前間隔,如果是正數則爲後
  * @return
  */
 public static Date getIntervalDate(Date appointDate,int type,int number) {
  Calendar intervalDate = Calendar.getInstance();
  intervalDate.setTime(appointDate);
  if(type == Calendar.YEAR){
   intervalDate.add(Calendar.YEAR, number);
  }else if(type == Calendar.MONTH){
   intervalDate.add(Calendar.MONTH, number);
  }else{
   intervalDate.add(Calendar.DATE, number);
  }
  return intervalDate.getTime();
 }

 public static void main(String[] args) {
  Date date1 = DateTimeUtils.parse("2011-03-30 22:22:22" , "yyyy-MM-dd HH:mm:ss");
  Date date2 = DateTimeUtils.parse("2011-10-12 22:22:22", "yyyy-MM-dd HH:mm:ss");
  System.out.println("相差：" + DateTimeUtils.getDiffYearsAndMonths(date1, date2));
  //System.out.println("相差：" + DateTimeUtils.getDiffDays(date1, date2));

  System.out.println(DateTimeUtils.format(date1, "yyyy-MM-dd HH:mm:ss"));
  
  System.out.println("獲得指定日期的上月最後一天的日期"+DateTimeUtils.format(DateTimeUtils.getPreviousMonthEnd(date1), "yyyy-MM-dd"));
  System.out.println("獲得指定日期的上月第一天的日期"+DateTimeUtils.format(DateTimeUtils.getPreviousMonthFirst(date1), "yyyy-MM-dd"));
  
  System.out.println("獲得指定日期第一天的日期"+DateTimeUtils.format(DateTimeUtils.getMonthEnd(date1), "yyyy-MM-dd"));
  System.out.println("獲得指定日期最後一天的日期"+DateTimeUtils.format(DateTimeUtils.getMonthFirst(date1), "yyyy-MM-dd"));
  
  System.out.println("獲得指定日期上個月的日期"+DateTimeUtils.format(DateTimeUtils.getNextMonthDate(date1), "yyyy-MM-dd"));
  System.out.println("獲得指定日期上個月的日期"+DateTimeUtils.format(DateTimeUtils.getPreviousMonthDate(date1), "yyyy-MM-dd"));
  
  System.out.println("獲得指定日期2年後的日期"+DateTimeUtils.format(DateTimeUtils.getIntervalDate(date1,Calendar.YEAR,2), "yyyy-MM-dd"));
  System.out.println("獲得指定日期2年前的日期"+DateTimeUtils.format(DateTimeUtils.getIntervalDate(date1,Calendar.YEAR,-2), "yyyy-MM-dd"));
  
  System.out.println("獲得指定日期15月後的日期"+DateTimeUtils.format(DateTimeUtils.getIntervalDate(date1,Calendar.MONTH,15), "yyyy-MM-dd"));
  System.out.println("獲得指定日期6月前的日期"+DateTimeUtils.format(DateTimeUtils.getIntervalDate(date1,Calendar.MONTH,-6), "yyyy-MM-dd"));
  
  System.out.println("獲得指定日期40天后的日期"+DateTimeUtils.format(DateTimeUtils.getIntervalDate(date1,Calendar.DATE,40), "yyyy-MM-dd"));
  System.out.println("獲得指定日期10天前的日期"+DateTimeUtils.format(DateTimeUtils.getIntervalDate(date1,Calendar.DATE,-10), "yyyy-MM-dd"));
 }

}