项目经验：自己写的根据时段得到日期的CalendarUtil

在做水质评价统计的时候，根据前台页面返回的最近一天、最近一星期、最近一月、最近一年计算出日期。

统计时段select控件：

CalendarUtil类代码：

package com.richway.waterevaluate.util;import java.util.Calendar;
import java.util.Date;/*** @author lej*时间处理工具* 2014-5-30下午1:43:02*/
public class CalendarUtil {/*** 得到当天的0:0:0:000*/public static Date getTodayStart(){Calendar calendar = Calendar.getInstance();  //将小时至0  calendar.set(Calendar.HOUR_OF_DAY, 0);  //将分钟至0  calendar.set(Calendar.MINUTE, 0);  //将秒至0  calendar.set(Calendar.SECOND,0);  //将毫秒至0  calendar.set(Calendar.MILLISECOND, 0);return calendar.getTime(); }/*** 得到当天第二天的0:0:0:000*/public static Date getTomorrowStart(){Calendar calendar = Calendar.getInstance();  calendar.add(Calendar.DAY_OF_MONTH, 1);//将小时至0  calendar.set(Calendar.HOUR_OF_DAY, 0);  //将分钟至0  calendar.set(Calendar.MINUTE, 0);  //将秒至0  calendar.set(Calendar.SECOND,0);  //将毫秒至0  calendar.set(Calendar.MILLISECOND, 0);return calendar.getTime(); }/*** 得到当天所在的星期的第一天的0:0:0:000*/public static Date getThisWeekStart(){Calendar calendar = Calendar.getInstance();  // 直接取周一calendar.set(Calendar.DAY_OF_WEEK, Calendar.MONDAY);    //将小时至0  calendar.set(Calendar.HOUR_OF_DAY, 0);  //将分钟至0  calendar.set(Calendar.MINUTE, 0);  //将秒至0  calendar.set(Calendar.SECOND,0);  //将毫秒至0  calendar.set(Calendar.MILLISECOND, 0);return calendar.getTime();}/*** 得到当天所在的星期的下一个星期第一天的0:0:0:000*/public static Date getNextWeekStart(){Calendar calendar = Calendar.getInstance();  // 取下周calendar.add(Calendar.WEEK_OF_YEAR, 1);// 取下周一calendar.set(Calendar.DAY_OF_WEEK, Calendar.MONDAY); //将小时至0  calendar.set(Calendar.HOUR_OF_DAY, 0);  //将分钟至0  calendar.set(Calendar.MINUTE, 0);  //将秒至0  calendar.set(Calendar.SECOND,0);  //将毫秒至0  calendar.set(Calendar.MILLISECOND, 0);return calendar.getTime();}/*** 得到当天所在的月份的第一天的0:0:0:000*/public static Date getThisMonthStart(){Calendar calendar = Calendar.getInstance();  // 得到当天是这月的第几天int dayOfMonth = calendar.get(Calendar.DAY_OF_MONTH);// 减去dayOfMonth,得到第一天的日期，因为Calendar用０代表每月的第一天，所以要减一calendar.add(Calendar.DAY_OF_MONTH, -(dayOfMonth-1));//将小时至0  calendar.set(Calendar.HOUR_OF_DAY, 0);  //将分钟至0  calendar.set(Calendar.MINUTE, 0);  //将秒至0  calendar.set(Calendar.SECOND,0);  //将毫秒至0  calendar.set(Calendar.MILLISECOND, 0);return calendar.getTime();}/*** 得到当天所在的月份的下一个月第一天的0:0:0:000*/public static Date getNextMonthStart(){Calendar calendar = Calendar.getInstance();  // 得到当天是这月的第几天int dayOfMonth = calendar.get(Calendar.DAY_OF_MONTH);// 减去dayOfMonth,得到第一天的日期，因为Calendar用０代表每月的第一天，所以要减一calendar.add(Calendar.DAY_OF_MONTH, -(dayOfMonth-1));//得到下一个月calendar.add(Calendar.MONTH, 1);//将小时至0  calendar.set(Calendar.HOUR_OF_DAY, 0);  //将分钟至0  calendar.set(Calendar.MINUTE, 0);  //将秒至0  calendar.set(Calendar.SECOND,0);  //将毫秒至0  calendar.set(Calendar.MILLISECOND, 0);return calendar.getTime();}/*** 得到当天所在的年份的第一天的0:0:0:000*/public static Date getThisYearStart(){Calendar calendar = Calendar.getInstance();  // 得到当天是今年的第几天int dayOfYEAR = calendar.get(Calendar.DAY_OF_YEAR);// 减去dayOfYEAR,得到第一天的日期，因为Calendar用０代表每月的第一天，所以要减一calendar.add(Calendar.DAY_OF_YEAR, -(dayOfYEAR-1));//将小时至0  calendar.set(Calendar.HOUR_OF_DAY, 0);  //将分钟至0  calendar.set(Calendar.MINUTE, 0);  //将秒至0  calendar.set(Calendar.SECOND,0);  //将毫秒至0  calendar.set(Calendar.MILLISECOND, 0);return calendar.getTime();}/*** 得到当天所在的年份的下一年第一天的0:0:0:000*/public static Date getNextYearStart(){Calendar calendar = Calendar.getInstance();  // 得到当天是今年的第几天int dayOfYEAR = calendar.get(Calendar.DAY_OF_YEAR);// 减去dayOfYEAR,得到第一天的日期，因为Calendar用０代表每月的第一天，所以要减一calendar.add(Calendar.DAY_OF_YEAR, -(dayOfYEAR-1));//得到下一个年calendar.add(Calendar.YEAR, 1);//将小时至0  calendar.set(Calendar.HOUR_OF_DAY, 0);  //将分钟至0  calendar.set(Calendar.MINUTE, 0);  //将秒至0  calendar.set(Calendar.SECOND,0);  //将毫秒至0  calendar.set(Calendar.MILLISECOND, 0);return calendar.getTime();}/*** 得到两个时间对应年份的间隔 */public static int getYearsBetween(Date startTime,Date endTime){Calendar calendar = Calendar.getInstance();  calendar.setTime(startTime);int year1 = calendar.get(Calendar.YEAR);    //获取年calendar.setTime(endTime);int year2 = calendar.get(Calendar.YEAR);    //获取年int between = year2-year1;return between;}//	当天开始Fri May 30 00:00:00 CST 2014
//	第二天开始Sat May 31 00:00:00 CST 2014
//	星期开始Mon May 26 00:00:00 CST 2014
//	下星期开始Mon Jun 02 00:00:00 CST 2014
//	当月开始Thu May 01 00:00:00 CST 2014
//	下月开始Sun Jun 01 00:00:00 CST 2014
//	当年开始Wed Jan 01 00:00:00 CST 2014
//	下年开始Thu Jan 01 00:00:00 CST 2015}