日期操作类

 package com.lcr.tools.util.date;

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

 public class DateTimeUtil implements Serializable {

     /**
     * serialVersionUID:TODO
     *
     * @author: lu chunli
     * @date:   2012-5-13 下午02:44:59
     * @version 1.0.0
     *
     */

     private static final long serialVersionUID = 1L;


     private  static final SimpleDateFormat longDateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");

     private  static final SimpleDateFormat shortDateFormat = new SimpleDateFormat("yyyy-MM-dd");

     /**
      * 根据一个日期，返回是星期几的字符串
      */
     private static String getWeek (String strDate) {
         // 再转换为时间
         Date date = null;
         try {
             date = shortDateFormat.parse(strDate);
         } catch (ParseException e) {
             e.printStackTrace();
         }
         Calendar calendar = Calendar.getInstance();
         calendar.setTime(date);

         return new SimpleDateFormat("EEEE").format(calendar.getTime());
     }

     /**
      * 取当天(短日期类型)
      */
     private static String getShortToday () {
         Date today = new Date();
         return shortDateFormat.format(today);
     }

     /**
      * 取当天(长日期类型)
      */
     private static String getLongToday () {
         Date today = new Date();
         return longDateFormat.format(today);
     }

     /**
      * 取当天零点零分零秒
      */
     private static String getTodayStart () {
         Calendar calendar = Calendar.getInstance();
         //如果没有这种设定的话回去系统的当期的时间
         calendar.set(Calendar.HOUR_OF_DAY, 0);
         calendar.set(Calendar.MINUTE, 0);
         calendar.set(Calendar.SECOND, 0);
         calendar.set(Calendar.MILLISECOND, 0);
         Date date = new Date(calendar.getTimeInMillis());
         return longDateFormat.format(date);
     }

     /**
      * 取当天23点59分59秒
      */
     private static String getTodayEnd () {
         Calendar calendar = Calendar.getInstance();
         calendar.set(Calendar.HOUR_OF_DAY, 23);
         calendar.set(Calendar.MINUTE, 59);
         calendar.set(Calendar.SECOND, 59);
         Date date = new Date(calendar.getTimeInMillis());
         return longDateFormat.format(date);
     }

     /**
      * 取特定日期的零点零分零秒
      */
     private static String getDateStart (String strDate) {
         if (null == strDate || "".equals(strDate.trim())) {
             return "";
         }
         Date date = null;
         try {
             date = shortDateFormat.parse(strDate);
         } catch (ParseException e) {
             e.printStackTrace();
         }
         return longDateFormat.format(date);
     }

     /**
      * 取特定日期的零点零分零秒
      */
     private static String getDateEnd (String strDate) {
         if (null == strDate || "".equals(strDate.trim())) {
             return "";
         }
         Date date = null;
         try {
             date = shortDateFormat.parse(strDate);
         } catch (ParseException e) {
             e.printStackTrace();
         }

         //这样能够取到59分59秒
         Calendar calendar = Calendar.getInstance();
         calendar.setTime(date);
         calendar.set(Calendar.HOUR_OF_DAY, 23);
         calendar.set(Calendar.MINUTE, 59);
         calendar.set(Calendar.SECOND, 59);
         calendar.set(Calendar.MILLISECOND, 0);

         return longDateFormat.format(calendar.getTime());
     }

     /**
      * 取当周周一
      */
     private static String getMondayOfThisWeek () {
         Calendar calendar = Calendar.getInstance();
         int day_of_week = calendar.get(Calendar.DAY_OF_WEEK) - 1;
         if (day_of_week == 0){
             day_of_week = 7;
         }
         calendar.add(Calendar.DATE, -day_of_week + 1);
         /*calendar.set(Calendar.HOUR_OF_DAY, 0);
         calendar.set(Calendar.MINUTE, 0);
         calendar.set(Calendar.SECOND, 0);
         calendar.set(Calendar.MILLISECOND, 0);*/
         return shortDateFormat.format(calendar.getTime());
     }

     /**
      * 取当周周日
      */
     private static String getSundayOfThisWeek () {
         Calendar calendar = Calendar.getInstance();
         int day_of_week = calendar.get(Calendar.DAY_OF_WEEK) - 1;
         if (day_of_week == 0){
             day_of_week = 7;
         }
         calendar.add(Calendar.DATE, -day_of_week + 1);
         /*calendar.set(Calendar.HOUR_OF_DAY, 0);
         calendar.set(Calendar.MINUTE, 0);
         calendar.set(Calendar.SECOND, 0);
         calendar.set(Calendar.MILLISECOND, 0);*/
         //以上取得的是周一
         calendar.add(Calendar.DATE, 6);
         return shortDateFormat.format(calendar.getTime());
     }

     /**
      * 取上周周一
      */
     private static String getMondayOfPreviousWeek () {
         Calendar calendar = Calendar.getInstance();
         int day_of_week = calendar.get(Calendar.DAY_OF_WEEK) - 1;
         if (day_of_week == 0){
             day_of_week = 7;
         }
         calendar.add(Calendar.DATE, -day_of_week + 1);
         calendar.add(Calendar.DATE, -7);
         return shortDateFormat.format(calendar.getTime());
     }

     /**
      * 取上周周日
      */
     private static String getSundayOfPreviousWeek () {
         Calendar calendar = Calendar.getInstance();
         int day_of_week = calendar.get(Calendar.DAY_OF_WEEK) - 1;
         if (day_of_week == 0){
             day_of_week = 7;
         }
         calendar.add(Calendar.DATE, -day_of_week + 1);
         calendar.add(Calendar.DATE, -1);
         return shortDateFormat.format(calendar.getTime());
     }

     /**
      * 取下周周一
      */
     private static String getMondayOfNextWeek () {
         Calendar calendar = Calendar.getInstance();
         int day_of_week = calendar.get(Calendar.DAY_OF_WEEK) - 1;
         if (day_of_week == 0){
             day_of_week = 7;
         }
         calendar.add(Calendar.DATE, -day_of_week + 1);  // 当周周一
         calendar.add(Calendar.DATE, 7);
         return shortDateFormat.format(calendar.getTime());
     }

     /**
      * 取下周周日
      */
     private static String getSundayOfNextWeek () {
         Calendar calendar = Calendar.getInstance();
         int day_of_week = calendar.get(Calendar.DAY_OF_WEEK) - 1;
         if (day_of_week == 0){
             day_of_week = 7;
         }
         calendar.add(Calendar.DATE, -day_of_week + 1);  // 当周周一
         calendar.add(Calendar.DATE, 13);
         return shortDateFormat.format(calendar.getTime());
     }

     /**
      * 取当月1号
      */
     private static String getFirstDayOfThisMonth () {
          Calendar calendar = Calendar.getInstance();
          calendar.set(Calendar.DATE, 1);    // 设为当前月的1号
          return shortDateFormat.format(calendar.getTime());
     }

     /**
      * 取当月最后一天
      */
     private static String getLastDayOfThisMonth () {
          Calendar calendar = Calendar.getInstance();
          calendar.set(Calendar.DATE, 1);    // 设为当前月的1号
          calendar.add(Calendar.MONTH, 1);   // 加一个月，变为下月的1号
          calendar.add(Calendar.DATE, -1);   // 减去一天，变为当月最后一天
          return shortDateFormat.format(calendar.getTime());
     }

     /**
      * 取上月1号
      */
     private static String getFirstDayOfPreviousMonth () {
          Calendar calendar = Calendar.getInstance();
          calendar.set(Calendar.DATE, 1);    // 设为当前月的1号
          calendar.add(Calendar.MONTH, -1);  // 减一个月，变为上月的1号
          return shortDateFormat.format(calendar.getTime());
     }

     /**
      * 取上月最后一天
      */
     private static String getLastDayOfPreviousMonth () {
          Calendar calendar = Calendar.getInstance();
          calendar.set(Calendar.DATE, 1);    // 设为当前月的1号
          calendar.add(Calendar.DATE, -1);   // 减去一天，变为上月最后一天
          return shortDateFormat.format(calendar.getTime());
     }

     /**
      * 取下月1号
      */
     private static String getFirstDayOfNextMonth () {
         Calendar calendar = Calendar.getInstance();
         calendar.add(Calendar.MONTH, 1);    // 加一个月
         calendar.set(Calendar.DATE, 1);     // 把日期设置为当月第一天
         return shortDateFormat.format(calendar.getTime());
     }

     /**
      * 取下月最后一天
      */
     private static String getLastDayOfNextMonth () {
         Calendar calendar = Calendar.getInstance();
         calendar.add(Calendar.MONTH, 1);// 加一个月
         calendar.set(Calendar.DATE, 1);// 把日期设置为当月第一天
         calendar.roll(Calendar.DATE, -1);// 日期回滚一天，也就是本月最后一天
         return shortDateFormat.format(calendar.getTime());
     }

     /**
      * 获得本年有多少天
      */
     private static int getTotalDaysOfThisYear() {
         Calendar calendar = Calendar.getInstance();
         calendar.set(Calendar.DAY_OF_YEAR, 1);// 把日期设为当年第一天
         calendar.roll(Calendar.DAY_OF_YEAR, -1);// 把日期回滚一天。
         int totalDays = calendar.get(Calendar.DAY_OF_YEAR);
         return totalDays;
     }

     /**
      * 获取某年某月的最后一天
      */
     private static int getLastDayOfMonth (int year, int month) {
         if (month == 1 || month == 3 || month == 5 || month == 7 || month == 8 || month == 10 || month == 12) {
             return 31;
         }
         if (month == 4 || month == 6 || month == 9 || month == 11) {
             return 30;
         }
         if (month == 2) {
             if (isLeapYear(year)) {
                 return 29;
             } else {
                 return 28;
             }
         }
         return 0;
     }

     /**
      * 是否闰年
      */
     public static boolean isLeapYear (int year) {
         return (year % 4 == 0 && year % 100 != 0) || (year % 400 == 0);
     }


     /**
      * 获得本年第一天的日期
      */
     public static String getFirstDayOfThisYear () {
         Calendar calendar = Calendar.getInstance();
         calendar.set(Calendar.MONTH, 1);
         calendar.set(Calendar.DAY_OF_YEAR, 1);
         Date date = new Date(calendar.getTimeInMillis());
         return shortDateFormat.format(date);
     }

     /**
      *  获得本年最后一天的日期
      */
     public static String getLastDayOfThisYear () {
         Date date = new Date();
         String years = new SimpleDateFormat("yyyy").format(date);
         return years + "-12-31";
     }

     /**
      *  获得上年第一天的日期 *
      */
     public static String getFirstDayOfPreviousYear () {
         Calendar calendar = Calendar.getInstance();
         calendar.add(Calendar.YEAR, -1);    // 若是 明年改为正整数1即可
         calendar.set(Calendar.MONTH, 1);
         calendar.set(Calendar.DAY_OF_YEAR, 1);
         Date date = new Date(calendar.getTimeInMillis());
         return shortDateFormat.format(date);
     }

     /**
      * 两个时间之间的天数
      */
     public static long getDays (String date1, String date2) {
         if (date1 == null || "".equals(date1.trim())) {
             return 0;
         }
         if (date2 == null || "".equals(date2.trim())) {
             return 0;
         }
         // 转换为标准时间
         Date date = null;
         Date mydate = null;
         try {
             date = shortDateFormat.parse(date1);
             mydate = shortDateFormat.parse(date2);
         } catch (Exception e) {
             e.printStackTrace();
         }
         long day = 0;
         if (date.before(mydate)) {
             day = (mydate.getTime() - date.getTime()) / (24 * 60 * 60 * 1000);
         } else {
             day = (date.getTime() - mydate.getTime()) / (24 * 60 * 60 * 1000);
         }
         return day;
     }

     /**
      *
      */
     public static void main(String[] args) {
         System.out.println("/*--------------------------两个时间之间的天数--------------------------*/");
         System.out.println("两个时间之间的天数1  :   " + getDays ("2012-05-10", "2012-05-15"));
         System.out.println("两个时间之间的天数2  :   " + getDays ("2012-06-10", "2012-05-15"));
         System.out.println("/*--------------------------获得上年第一天的日期--------------------------*/");
         System.out.println("获得上年第一天的日期  :   " + getFirstDayOfPreviousYear ());
         System.out.println("/*--------------------------获得本年最后一天的日期--------------------------*/");
         System.out.println("获得本年最后一天的日期 :   " + getLastDayOfThisYear ());
         System.out.println("/*--------------------------获得本年第一天的日期--------------------------*/");
         System.out.println("获得本年第一天的日期  :   " + getFirstDayOfThisYear ());
         System.out.println("/*--------------------------获取某年某月的最后一天--------------------------*/");
         System.out.println("获取某年某月的最后一天 :   " + getLastDayOfMonth (2012, 5));
         System.out.println("/*--------------------------------是否闰年---------------------------------*/");
         System.out.println("是否闰年                :   " + isLeapYear(2012));
         System.out.println("/*--------------------------获得本年有多少天--------------------------*/");
         System.out.println("获得本年有多少天        :   " + getTotalDaysOfThisYear());
         System.out.println("/*--------------------------下月1号和最后一天--------------------------*/");
         System.out.println("下月1号                :   " + getFirstDayOfNextMonth());
         System.out.println("下月最后一天          :   " + getLastDayOfNextMonth ());
         System.out.println("/*--------------------------上月1号和最后一天--------------------------*/");
         System.out.println("上月1号                :   " + getFirstDayOfPreviousMonth());
         System.out.println("上月最后一天          :   " + getLastDayOfPreviousMonth ());
         System.out.println("/*--------------------------当月1号和最后一天--------------------------*/");
         System.out.println("当月1号                :   " + getFirstDayOfThisMonth());
         System.out.println("当月最后一天          :   " + getLastDayOfThisMonth ());
         System.out.println("/*--------------------------当月1号和最后一天--------------------------*/");
         System.out.println("当月1号                :   " + getFirstDayOfThisMonth());
         System.out.println("当月最后一天          :   " + getLastDayOfThisMonth ());
         System.out.println("/*--------------------------下周周一和周日--------------------------*/");
         System.out.println("下周周一                :   " + getMondayOfNextWeek());
         System.out.println("下周周日                :   " + getSundayOfNextWeek ());
         System.out.println("/*--------------------------上周周一和周日--------------------------*/");
         System.out.println("上周周一                :   " + getMondayOfPreviousWeek());
         System.out.println("上周周日                :   " + getSundayOfPreviousWeek ());
         System.out.println("/*--------------------------当周周一和周日--------------------------*/");
         System.out.println("当周周一                :   " + getMondayOfThisWeek ());
         System.out.println("当周周日                :   " + getSundayOfThisWeek ());
         System.out.println("/*--------------------------特定日期(零点和23点)--------------------------*/");
         System.out.println("特定日期(23点59分59秒) :   " + getDateEnd ("2012-05-12"));
         System.out.println("特定日期(零点零分零秒)    :   " + getDateStart ("2012-05-12"));
         System.out.println("/*--------------------------当天(零点和23点)--------------------------*/");
         System.out.println("当天(23点59分59秒)   :   " + getTodayEnd ());
         System.out.println("当天(零点零分零秒)  :   " + getTodayStart ());
         System.out.println("/*---------------------------当天(长日期格式和短日期格式)-------------------------*/");
         System.out.println("当天(长日期格式)       :   " + getLongToday ());
         System.out.println("当天(短日期格式)       :   " + getShortToday ());
         System.out.println("/*---------------------------当天(长日期格式和短日期格式)-------------------------*/");
         System.out.println("根据一个日期，返回是星期几的字符串       :   " + getWeek ("2012-05-12"));
     }
 }