import java.util.Calendar;
import java.util.Date;
/**
* 功能：计算时间
* 上月开始、上月结束、本月开始、本月结束、上周开始、上周结束、本周开始、本周结束、昨天开始、昨天结束、今天开始、今天结束
* @see
* @version 2007-06-07
*
*/
public class StartAndEndOfDate {
public static enum DateTag {LAST_MONTH_START,LAST_MONTH_END,THIS_MONTH_START,THIS_MONTH_END,LAST_WEEK_START,LAST_WEEK_END,
THIS_WEEK_START,THIS_WEEK_END,YESTERDAY_START,YESTERDAY_END,TODAY_START,TODAY_END,NOW};
/**
* 功能：计算时间
* 上月开始、上月结束、本月开始、本月结束、上周开始、上周结束、本周开始、本周结束、昨天开始、昨天结束、今天开始、今天结束
* 格式：2007-06-01 00:00:00 2007-06-30 23:59:59
* 本月结束、本周结束、今天结束 都指的是当前日期时间
* 一周按照：星期一至星期天来计算
* @param tag
* @return String
*/
public static String getStartAndEndDate(DateTag tag){
String resultString;
Calendar cal = Calendar.getInstance();
Date date = new Date();
java.text.DateFormat formatFull = new java.text.SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
String now = formatFull.format(date);
java.text.DateFormat format = new java.text.SimpleDateFormat("yyyy-MM-dd");
switch (tag){
case LAST_MONTH_START://上月开始
cal.add(Calendar.MONTH, -1);
cal.set(Calendar.DATE, 1);
String lastMonthStart = format.format(cal.getTime())+" 00:00:00";//上月开始（上月1号）
cal.clear();
resultString = lastMonthStart;
break;
case LAST_MONTH_END://上月结束
cal=Calendar.getInstance();
cal.add(Calendar.MONTH, -1);
cal.set(Calendar.DATE,cal.getActualMaximum(Calendar.DAY_OF_MONTH));
String lastMonthEnd = format.format(cal.getTime())+" 23:59:59";//上月结束（上月最后一天）
cal.clear();
resultString = lastMonthEnd;
break;
case THIS_MONTH_START://本月开始
cal=Calendar.getInstance();
cal.add(Calendar.MONDAY,0);
cal.set(Calendar.DAY_OF_MONTH, 1);
String thisMonthStart = format.format(cal.getTime())+" 00:00:00";//本月开始（本月1号）
cal.clear();
resultString = thisMonthStart;
break;
case THIS_MONTH_END://本月结束
String thisMonthEnd = now;//本月结束（即：当前时间）
resultString = thisMonthEnd;
break;
case LAST_WEEK_START://上周开始
cal=Calendar.getInstance();
cal.add(Calendar.WEEK_OF_YEAR, -1);
cal.set(Calendar.DAY_OF_WEEK, Calendar.MONDAY);
String lastWeekStart = format.format(cal.getTime())+" 00:00:00";//上周开始（即：上周一）
cal.clear();
resultString = lastWeekStart;
break;
case LAST_WEEK_END://上周结束
cal=Calendar.getInstance();
cal.add(Calendar.WEEK_OF_YEAR, 0);
cal.set(Calendar.DAY_OF_WEEK, Calendar.SUNDAY);
String lastWeekEnd = format.format(cal.getTime())+" 23:59:59";//上周结束（即：上周日）
cal.clear();
resultString = lastWeekEnd;
break;
case THIS_WEEK_START://本周开始
cal=Calendar.getInstance();
cal.add(Calendar.WEEK_OF_YEAR, 0);
cal.set(Calendar.DAY_OF_WEEK, Calendar.MONDAY);
String thisWeekStart = format.format(cal.getTime())+" 00:00:00";//本周开始（即：本周一）
cal.clear();
resultString = thisWeekStart;
break;
case THIS_WEEK_END://本周结束
String thisWeekEnd = now;//本周结束(即：当前时间)
resultString = thisWeekEnd;
break;
case YESTERDAY_START://昨天开始
cal = Calendar.getInstance();
cal.add(Calendar.DAY_OF_MONTH, -1);
format = new java.text.SimpleDateFormat("yyyy-MM-dd");
String yesterdayStart= format.format(cal.getTime());
yesterdayStart = yesterdayStart+" 00:00:00";//昨天开始
cal.clear();
resultString = yesterdayStart;
break;
case YESTERDAY_END://昨天结束
cal = Calendar.getInstance();
cal.add(Calendar.DAY_OF_MONTH, -1);
format = new java.text.SimpleDateFormat("yyyy-MM-dd");
String yesterdayEnd= format.format(cal.getTime());
yesterdayEnd = yesterdayEnd+" 23:59:59";//昨天结束
cal.clear();
resultString = yesterdayEnd;
break;
case TODAY_START://今天开始
String todayStart=format.format(date)+" 00:00:00";//今天开始
resultString = todayStart;
break;
case TODAY_END://今天结束
String todayEnd = now;//今天结束（即；当前时间）
resultString = todayEnd;
break;
default://没有匹配的，返回当前时间
resultString = now;
}
return resultString;
}
}