package com.tenwa.reckon.util;

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

import org.springframework.util.Assert;


/**
 * 
 * <p>Date时间处理工具类。</p>
 * @author sea
 * @version 2.0
 * <p>2012-6-4</p>
 */
public class DateUtils {

	/**
	 * log4日志
	 */

	/**
	 * 默认日期格式
	 */
	private static SimpleDateFormat df = new SimpleDateFormat("yyyyMMdd");

	/**
	 * 默认日期时间格式
	 */
	private static SimpleDateFormat timeFormat = new SimpleDateFormat("yyyyMMddHHmm");

	/**
	 * 
	 * <p>返回当前日期。</p>
	 * @author sea
	 * @return Date
	 */
	public static Date getCurrentDate() {
		return new Date();

	}
	/**
	 * <p>返回当前日期。</p>
	 * @author sea
	 * @param date
	 * @return String
	 */
	public static String getNullDate(String date) {
		String tempDate = date;
		if (date == null || "".equals(date)) {
			tempDate = getSystemDate(0);
		}
		return tempDate;
	}

	  /**
	   * <p>转换日期为指定格式的字符串。</p>
	   * <p>2008-7-1</p>
	   * @author sea
	   * @param date 日期
	   * @param stringformat 字符串格式，表示日期转换成字符串的格式。例如（YYYY-MM-DD,YYYY/MM/DD）
	   * @return String 
	   */
	  public static String date2String(Date date, String stringformat) {
		//断言  
	    SimpleDateFormat df = new SimpleDateFormat(stringformat);
	    return df.format(date);
	  }
	  
	  /**
	     * days360算法
	     *  如果起始日期是一个月的最后一天，则等于同月的 30 号。 如果终止日期是一个月的最后一天，并且起始日期早于 30 号，
	     *  则终止日期等于下一个月的 1 号，否则，终止日期等于本月的 30 号。
	     */
	    public static int days360(String start_date,String end_date)throws Exception{
	    	Assert.notNull(start_date);
	    	Assert.notNull(end_date);
	    	boolean flag = true;
	    	Integer startYear = Integer.parseInt(start_date.substring(0, 4)) ;
	    	Integer startDay = Integer.parseInt(start_date.substring(8, 10)) ;
	    	Integer startMonth = Integer.parseInt(start_date.substring(5,7));
	    	Integer endDay = Integer.parseInt(end_date.substring(8, 10));
	    	Integer endYear = Integer.parseInt(end_date.substring(0, 4)) ;
	    	Integer endMonth = Integer.parseInt(end_date.substring(5, 7));
	    	if(getCompareDate(start_date,end_date) > 0){
	    		flag = false;
	    		endYear = Integer.parseInt(start_date.substring(0, 4)) ;
	    		endDay = Integer.parseInt(start_date.substring(8, 10)) ;
	    		endMonth = Integer.parseInt(start_date.substring(5,7));
	        	startDay = Integer.parseInt(end_date.substring(8, 10));
	        	startYear = Integer.parseInt(end_date.substring(0, 4)) ;
	        	startMonth = Integer.parseInt(end_date.substring(5, 7));
	    	}
	    	if(startDay == getLastDayOfMonth(startYear,startMonth)){
	    		startDay = 30;
	    	}
	    	if(endDay == 31){
	    		if(startDay == 30){
	    			endDay = 30;
	    		}else{
	    			endDay = 1;
	    			endMonth ++;
	    		}
	    	}
	    	Integer betweenDay = 0;
	    	if(Math.abs(startYear - endYear) == 0){//代表是同年的日期间隔
	    		betweenDay = getSameYearDays360(startMonth,startDay,endMonth,endDay);
	    	}else if (Math.abs(startYear - endYear) == 1){
	    		betweenDay += getSameYearDays360(startMonth,startDay,12,30);
	    		betweenDay += getSameYearDays360(1,1,endMonth,endDay) + 1 ;
	    	}else{
	    		Integer betweenYear = endYear - startYear;
	    		betweenDay += (betweenYear-1)*360;
	    		betweenDay += getSameYearDays360(startMonth,startDay,12,30);
	    		betweenDay += getSameYearDays360(1,1,endMonth,endDay) + 1 ;
	    	}
	    	if(!flag){
	    		betweenDay = 0- betweenDay;
	    	}
	    	return betweenDay;
	    }
	    
	    private static int getSameYearDays360(int startMonth,int startDay,int endMonth , int endDay){
	    	Integer betweenDay = 0;
	    	if(Math.abs(startMonth - endMonth) == 0){//代表的是同月
				betweenDay = endDay - startDay;
			}else if(Math.abs(startMonth - endMonth) == 1){//跨一个月
					betweenDay = 30-startDay + endDay;
			}else{//跨N个月
				Integer betweenMonth = endMonth - startMonth;
				betweenDay = (betweenMonth - 1) * 30  + 30-startDay + endDay;
			}
	    	return betweenDay;
	    }
	    private static int getLastDayOfMonth(int year, int month) { 
	    	Calendar cal = Calendar.getInstance(); 
	    	cal.set(Calendar.YEAR, year); 
	    	cal.set(Calendar.MONTH, month);
	    	cal.set(Calendar.DAY_OF_MONTH, 1);
	    	cal.add(Calendar.DAY_OF_MONTH, -1);
	    	// 某年某月的最后一天 
	    	return cal.get(Calendar.DAY_OF_MONTH); 
	    } 
	  /**
	   * <p>格式化字符串日期。</p>
	   * <p>2008-7-1</p>
	   * @author sea
	   * @param date String
	   * @return String  YYYY-MM-DD
	   */
	  public static String date2Str(String date) {
	    if (date == null) {
	      return "";
	    }
	    SimpleDateFormat sdf = new SimpleDateFormat("yyyy/MM/dd");
	    try {
			date = sdf.format( sdf.parse(date) );
		} catch (ParseException e) {
			e.printStackTrace();
		}
	    
	    return date;
	  }
	  
	  /**
	   * <p>转换日期为字符串。</p>
	   * <p>2008-7-1</p>
	   * @author sea
	   * @param date
	   * @return Object  YYYY-MM-DD HH:mm:ss
	   */
	  public static String date2String(Date date) {
		  if (date == null) {
			  return "";
		  }
		  String format = "yyyy/MM/dd HH:mm:ss";
		  return date2String(date, format);
	  }
	  
	  /**
	   * <p>转换日期为字符串，不带时分秒。</p>
	   * <p>2008-7-1</p>
	   * @author sea
	   * @param date
	   * @return Object
	   */
	  public static String dateToString(Date date) {
	    if (date == null) {
	      return "";
	    }
	    String format = "yyyy/MM/dd";
	    return date2String(date, format);
	  }
	  
	  /**
	   * <p>转换字符串类型为日期类型。</p>
	   * <pre>格式为yyyyMMdd</pre>
	   * <p>2008-7-1</p>
	   * @author sea
	   * @param string 日期字符串
	   * @return Date 日期，字符串转换后的日期
	   * @throws ParseException
	   */
	  public static Date toDate(String string) throws ParseException {
	    Date cDate = null;
	    df.setLenient(true);
	    cDate = df.parse(string);
	    return cDate;
	  }
	  
	  /**
	   * <p>转换字符串类型为日期时间类型。</p>
	   * <pre>格式为yyyyMMddHHmm</pre>
	   * <p>2008-7-1</p>
	   * @author sea
	   * @param string 日期时间字符串
	   * @return Date 日期，字符串转换后的日期时间
	   * @throws ParseException
	   */
	  public static Date toTime(String string) throws ParseException {
	    Date cDate = null;
	    timeFormat.setLenient(true);
	    cDate = timeFormat.parse(string);
	    return cDate;
	  }
	  
	  /**
	   * <p>将日期对象格式化为指定format的日期对象。</p>
	   * <pre>如果格式中包含小时、分钟、秒、毫秒，格式后的Date对象中该项值将为0</pre>
	   * <p>2007-8-31</p>
	   * @author sea
	   * @since 1.1
	   * @param date
	   * @param formatString
	   * @return Date
	   * @throws ParseException
	   */
	  public static Date format(Date date, String formatString)
	      throws ParseException {
	    String ds = date2String(date, formatString);
	    return toDate(formatString, ds);
	  }
	  /**
	   * <p>获取指定日期当日第一秒的日期。</p>
	   * <pre>如:2007-8-11日，返回的为2007-8-11 00:00:00</pre>
	   * <p>2007-8-31</p>
	   * @author sea
	   * @since 1.1
	   * @param date
	   * @return Date
	   */
	  public static Date getFirstSecondDate(Date date) {
	    Date retDate = null;
	    try {
	      retDate = format(date, "yyyy/MM/dd 00:00:00");
	    }
	    catch (ParseException e) {
	      e.printStackTrace();
	    }
	    return retDate;
	  }

	  /**
	   * <p>获取指定日期当日最后一秒的日期。</p>
	   * <pre>如:2007-8-11日，返回的为2007-8-11 23:59:59</pre>
	   * <p>2007-8-31</p>
	   * @author sea
	   * @since 1.1
	   * @param date
	   * @return Date
	   */
	  public static Date getLastSecondDate(Date date) {
	    Date tmpDate = getFirstSecondDate(date);
	    GregorianCalendar cal = new GregorianCalendar();
	    cal.setTime(tmpDate);
	    cal.add(GregorianCalendar.DATE, 1);
	    cal.add(GregorianCalendar.SECOND, -1);
	    return cal.getTime();
	  }

	  /**
	   * <p>转换日期字符串为指定格式的日期对象。</p>
	   * <p>2008-7-1</p>
	   * @author sea
	   * @param dateFormat 日期的格式字符串
	   * @param dateString 日期字符串
	   * @return Date 转换后的日期对象
	   * @throws ParseException
	   */
	  public static Date toDate(String dateFormat, String dateString)throws ParseException {
	    Date cDate = null;
	    SimpleDateFormat sdf = new SimpleDateFormat(dateFormat);
	    sdf.setLenient(true);
	    cDate = sdf.parse(dateString);
	    return cDate;
	  }

	  /**
	   * <p>判断字符串是否为日期类型。</p>
	   * <p>2008-7-1</p>
	   * @author sea
	   * @param dateStr 传入的字符串
	   * @param stringformat 日期类型的格式（例如2007/12/12，20071212，2007-12-12）
	   * @return Boolean
	   */
	  public static Boolean isDate(String dateStr, String stringformat) {
	    SimpleDateFormat sdf = new SimpleDateFormat(stringformat);
	    final String STR = "0123456789/-:";
	    if (dateStr.length() != stringformat.length()) {
	      return false;
	    }
	    else {
	      for (int i = 0; i < dateStr.length(); i++) {
	        if (STR.indexOf(dateStr.substring(i, i + 1)) == -1) {
	          return false;
	        }
	      }
	      try {
	        sdf.setLenient(false);
	        sdf.parse(dateStr);
	        return true;
	      }
	      catch (ParseException e) {
	        return false;
	      }
	    }
	  }

	  /**
	   * <p>参数和现在的系统时间所差的天数。</p>
	   * <p>2008-7-1</p>
	   * @author sea
	   * @param date
	   * @return 对应的属性值
	   */
	  public static int gap(Date date) {

	    Calendar before = Calendar.getInstance();
	    Calendar current = Calendar.getInstance();
	    before.setTime(date);
	    current.setTime(new Date());
	    return (int) ((current.getTimeInMillis() - before.getTimeInMillis()) / (1000 * 60 * 60));
	  }

	  /**
	   * <p>返回两个时间的差数 。</p>
	   * <p>2008-7-1</p>
	   * @author sea
	   * @param date1 要比较的时间
	   * @param date2 参考时间
	   * @return result 相差的小时时间
	   */
	  public static int getBetweenHours(Date date1, Date date2) {
	    if (date1 == null || date2 == null)
	      return 0;
	    Calendar cal1 = new GregorianCalendar(Locale.CHINA);
	    Calendar cal2 = new GregorianCalendar(Locale.CHINA);
	    cal1.setTime(date1);
	    cal2.setTime(date2);

	    long timeMillis1 = cal1.getTimeInMillis();
	    long timeMillis2 = cal2.getTimeInMillis();
	    long result = (timeMillis2 - timeMillis1) / (1000 * 60 * 60);
	    return (int) result;
	  }
	  

	  /**
	   * <p>返回两个时间的差数。</p>
	   * <p>2008-7-1</p>
	   * @author sea
	   * @param date1 要比较的时间
	   * @param date2 参考时间
	   * @return result 相差的小时时间
	   */
	  public static long getBetweenMins(Date date1, Date date2) {
	    if (date1 == null || date2 == null)
	      return 0;
	    Calendar cal1 = new GregorianCalendar(Locale.CHINA);
	    Calendar cal2 = new GregorianCalendar(Locale.CHINA);
	    cal1.setTime(date1);
	    cal2.setTime(date2);

	    long timeMillis1 = cal1.getTimeInMillis();
	    long timeMillis2 = cal2.getTimeInMillis();
	    long result = (timeMillis2 - timeMillis1) / (1000 * 60);
	    return result;
	  }  

	  /**
	   * <p>返回与当前时间相差的小时数 。</p>
	   * <p>2008-7-1</p>
	   * @author sea
	   * @param date 要比较的时间
	   * @return result 相差的小时时间
	   */
	  public static int getBetweenHours(Date date) {
	    Calendar cal1 = new GregorianCalendar(Locale.CHINA);
	    Calendar cal2 = new GregorianCalendar(Locale.CHINA);
	    cal1.setTime(date);
	    cal2.setTime(new Date());

	    long timeMillis1 = cal1.getTimeInMillis();
	    long timeMillis2 = cal2.getTimeInMillis();
	    long result = (timeMillis2 - timeMillis1) / (1000 * 60 * 60);
	    return (int) result;
	  }

	  /**
	   * <p>相差的月份间隔。</p>
	   * <p>2008-7-1</p>
	   * @author sea
	   * @param bdate
	   * @param edate
	   * @return 相差的月份间隔
	   */
	  public static int getBetweenMonths(Date bdate, Date edate) {
	    Calendar cal1 = new GregorianCalendar(Locale.CHINA);
	    Calendar cal2 = new GregorianCalendar(Locale.CHINA);
	    cal1.setTime(bdate);
	    cal2.setTime(edate);
	    return cal2.get(Calendar.MONTH) - cal1.get(Calendar.MONTH)
	        + (cal2.get(Calendar.YEAR) - cal1.get(Calendar.YEAR)) * 12;
	  }
	  
	  /**
	   * <p>返回指定日期前N天的日期。</p>
	   * @author sea
	   * @param cureentDate 当前指定的日期
	   * @param n 指定的天数
	   * @return Date
	   */
	  public static Date getBeforeDate(Date cureentDate,int n) {
	    Date beforeDate = new Date();
	    beforeDate.setTime(cureentDate.getTime() - 24*60*60*1000*n);
	    return beforeDate;
	  }
	  
	  /**
	   * <p>返回指定日期后N天的日期。</p>
	   * @author sea
	   * @param cureentDate 当前指定的日期
	   * @param n 指定的天数
	   * @return Date
	   */
	  public static Date getAfterDate(Date cureentDate,int n) {
	    Date afterDate = new Date();
	    afterDate.setTime(cureentDate.getTime() + 24*60*60*1000*n);
	    return afterDate;
	  }
	  
	  /**
	   * <p>当前日期与该日期之间的天数。</p>
	   * @author sea
	   * @param dateString
	   * @return long
	   */
	  public static long getBetweenDays(String dateString){
	    try {
	      java.util.Date dt1 =DateUtils.format(DateUtils.toDate("yyyy/MM/dd", dateString), "yyyy/MM/dd hh:mm:ss");   
	      java.util.Date dt2 = new   java.text.SimpleDateFormat("yyyy/MM/dd hh:mm:ss").parse(DateUtils.date2String(DateUtils.getCurrentDate(), "yyyy/MM/dd hh:mm:ss"));   
	      Calendar t1 = Calendar.getInstance();   
	      Calendar t2 = Calendar.getInstance();   
	      t1.setTime(dt1);   
	      t2.setTime(dt2);   
	      long temp = (t2.getTimeInMillis()-t1.getTimeInMillis())/(1000*60*60*24);     
	      return temp;
	    }
	    catch (ParseException e) {
	      e.printStackTrace();
	      return -1;
	    }
	  }
	  
	  /**
	   * <p>计算两个日期之间的小时数。</p>
	   * @author sea
	   * @param dateA String
	   * @param dateB String
	   * @return int
	   */
	  public static int getBetweenHours(String dateA, String dateB) {
	    long dayNumber = 0;
	    //1小时=60分钟=3600秒=3600000
	    //long mins = 60L * 1000L;
	    long hours=3600000;
	    //long day= 24L * 60L * 60L * 1000L;计算天数之差
	    SimpleDateFormat df = new SimpleDateFormat("yyyy/MM/dd HH:mm:ss");
	    try {
	       java.util.Date d1 = df.parse(dateA);
	       java.util.Date d2 = df.parse(dateB);
	       dayNumber = (d2.getTime() - d1.getTime()) / hours;
	    } catch (Exception e) {
	       e.printStackTrace();
	    }
	    return (int) dayNumber;
	    }
	  
	  /**
	   * <p>计算两个日期之间的天数。</p>
	   * @author sea
	   * @param date1
	   * @param date2
	   * @return long
	   */
	  public static long DateDays(String date1, String date2){
	      SimpleDateFormat formatter = new SimpleDateFormat("yyyy/MM/dd");
	      long myTime;
	      Date aDate2;
	      Date aDate;
	      long myTime2;
	      long days = 0;
	      try {
	          aDate = formatter.parse(date1);// 任意日期，包括当前日期
	          myTime = (aDate.getTime() / 1000);
	          // SimpleDateFormat formatter =new SimpleDateFormat("yyyy/MM/dd");
	          aDate2 = formatter.parse(date2);// 任意日期，包括当前日期
	          myTime2 = (aDate2.getTime() / 1000);

	          if (myTime > myTime2) {
	              days = (myTime - myTime2) / (1 * 60 * 60 * 24);
	          } else {
	              days = (myTime2 - myTime) / (1 * 60 * 60 * 24);
	          }

	      } catch (Exception e) {
	          e.printStackTrace();
	      }
	      return days;
	  }
	
	/**
	 * 
	 * <p>日期格式化操作，格式化为不带时分秒的格式，如为空则返回空串。</p>
	 * @author sea
	 * @param datestr
	 * @return
	 */
	public static String getDBDateStr(String datestr) {
		try {
			String temp_date = datestr;
			if ((temp_date == null) || (temp_date.equals(""))
					|| (temp_date.indexOf("1900") >= 0)) {
				temp_date = "";
			} else {
				temp_date = temp_date.substring(0, 10);
			}
			return temp_date;
		} catch (Exception e) {

		}
		return "";
	}

	
	/**
	 * <p>返回系统时间 0--返回时间字符串 1--返回SQL时间字符串。</p>
	 * @author sea
	 * @param rtype 默认：yyyy-MM-dd，2：yyyyMMdd，3：yyyy-MM-dd HH:mm:ss ,4:yyyy/MM/dd HH:mm:ss
	 * @return
	 */
	public static String getSystemDate(int rtype) {
		try {
			Calendar cal = Calendar.getInstance();
			String module = "yyyy/MM/dd";
			if (rtype == 2) {
				module = "yyyyMMdd";
			}
			if (rtype == 3) {
				module = "yyyy/MM/dd HH:mm:ss";
			}
			if (rtype == 4) {
				module = "yyyy/MM/dd HH:mm:ss";
			}
			SimpleDateFormat formatter1 = new SimpleDateFormat(module);
			String fld_date = formatter1.format(cal.getTime());
			if (rtype == 0)
				return fld_date;
			else if (rtype == 1)
				return "'" + fld_date + "'"; // sql server
			else
				return fld_date;
		} catch (Exception e) {

		}
		return "null";
	}
	
	/**
	 * <p>在原有的日期 对象上添加值可以为年月日时分秒。</p>
	 * @author sea
	 * @param date 所要添加的日期
	 * @param leng 所要添加数
	 * @param type 添加的类型 :年YEAR/月MONTH/日DAY_OF_YEAR/时HOUR_OF_DAY/分MINUTE
	 * @return
	 */ 
	public static Date getDateAdd(Date date, int leng, String type) {
		Date addDate = null;
		Calendar cal = Calendar.getInstance();
		cal.setTime(date);
		if (type.equals("yy")) {
			cal.add(Calendar.YEAR, leng);
		} else if (type.equals("mm")) {
			cal.add(Calendar.MONTH, leng);
		} else if (type.equals("we")) {
			cal.add(Calendar.WEEK_OF_YEAR, leng);
		} else if (type.equals("dd")) {
			cal.add(Calendar.DAY_OF_YEAR, leng);
		} else if (type.equals("hh")) {
			cal.add(Calendar.HOUR_OF_DAY, leng);
		} else if (type.equals("mi")) {
			cal.add(Calendar.MINUTE, leng);
		} else if (type.equals("ss")) {

		}
		addDate = cal.getTime();
		return addDate;
	}

	/**
	 * <p>获得一月中的最后一天。</p>
	 * @author sea
	 * @param year 年
	 * @param month 月份
	 * @return
	 */ 
	public static String getLastDayOfMonth(String year, String month) {
		Calendar cal = Calendar.getInstance();
		// 年
		cal.set(Calendar.YEAR, Integer.parseInt(year));
		// 月，因为Calendar里的月是从0开始，所以要-1
		cal.set(Calendar.MONTH, Integer.parseInt(month) - 1);
		// 日，设为一号
		cal.set(Calendar.DATE, 1);
		// 月份加一，得到下个月的一号
		cal.add(Calendar.MONTH, 1);
		// 下一个月减一为本月最后一天
		cal.add(Calendar.DATE, -1);
		return String.valueOf(cal.get(Calendar.DAY_OF_MONTH));// 获得月末是几号
	}


	/**
	 * <p>返回一个日期的下一年的第一天。</p>
	 * @author sea
	 * @param chargeDate  
	 * @return
	 */ 
	public static String getYearFirstDay(String chargeDate) {
		Date date;
		String rdate = "";
		try {
			date = toDate(chargeDate);
			rdate = date2String(getDateAdd(date, 1, "yy"),"yyyy/MM/dd"); 
			rdate = rdate.substring(0, 4) + "-01-01";
		} catch (ParseException e) {
			e.printStackTrace();
		} 
		return rdate;

	}
 
	/**
	 * <p>得到下个月的第一天。</p>
	 * @author sea
	 * @param chargeDate  
	 * @return
	 */ 
	public static String getMonthFirstDay(String chargeDate) {
		Date date;
		String rdate = "";
		try {
			date = toDate(chargeDate);
			rdate = date2String(getDateAdd(date, 1, "mm"),"yyyy/MM/dd"); 
			rdate = rdate.substring(0, rdate.length() - 2) + "01";
		} catch (ParseException e) {
			e.printStackTrace();
		} 
		return rdate;
	}

	/**
	 * <p>得到一个日期的年份。</p>
	 * @author sea
	 * @param strDate  
	 * @return
	 */ 
	public static String getDateYear(String strDate) throws ParseException {
		SimpleDateFormat sdf = new SimpleDateFormat("yyyy/MM/dd");
		Calendar date = Calendar.getInstance();
		date.setTime(sdf.parse(strDate));
		return String.valueOf(date.get(Calendar.YEAR));

	}

	/**
	 * <p>得到一个日期的月份。</p>
	 * @author sea
	 * @param strDate  
	 * @return
	 */ 
	public static String getDateMonth(String strDate) throws ParseException {
		SimpleDateFormat sdf = new SimpleDateFormat("yyyy/MM/dd");
		Calendar date = Calendar.getInstance();
		date.setTime(sdf.parse(strDate));
		return String.valueOf(date.get(Calendar.MONTH) + 1);

	}

	/**
	 * <p>得到一个日期的天数。</p>
	 * @author sea
	 * @param strDate  
	 * @return
	 */ 
	public static String getDateDay(String strDate) throws ParseException {
		SimpleDateFormat sdf = new SimpleDateFormat("yyyy/MM/dd");
		Calendar date = Calendar.getInstance();
		date.setTime(sdf.parse(strDate));
		return String.valueOf(date.get(Calendar.DAY_OF_MONTH));
	}
	
    /**
     * <p>比较2个日期大小。</p>
     * @author 小谢
     * @param s1 日期1
     * @param s2 日期2
     * @return s1 > s2 return 1,s1 = s2 return 0,s1 < s2 return -1
     */
    public static int getCompareDate(String s1,String s2){
    	int flag = 0;
    	//String s1="2008-01-25";
		//String s2="2008-01-25";
		java.text.DateFormat df=new java.text.SimpleDateFormat("yyyy/MM/dd");
		java.util.Calendar c1=java.util.Calendar.getInstance();
		java.util.Calendar c2=java.util.Calendar.getInstance();
		try
		{
			c1.setTime(df.parse(s1));
			c2.setTime(df.parse(s2));
		}catch(java.text.ParseException e){
			System.err.println("日期格式不正确");
		}
		int result = c1.compareTo(c2);
		if(result==0){
			flag = 0;
			System.out.println("c1相等c2");
		}
		else if(result<0){
			flag = -1;
			System.out.println("c1小于c2");
		}
		else{
			flag = 1;
			System.out.println("c1大于c2");
		}
		return flag;
    }
    
    public static boolean isValidDate(String s){
		try{
			SimpleDateFormat sdf = new SimpleDateFormat("yyyy/MM/dd");
			sdf.parse( s);
			return true;
		}catch(Exception e){
			return false;
		}
	}
    
    public static int getBetweenMonths(String bdate, String edate,String format)throws Exception {
		  SimpleDateFormat sdf = new SimpleDateFormat(format);
		  return getBetweenMonths(sdf.parse(bdate),sdf.parse(edate));
	  }
}