博客

/**
     * 将日期，向前或向后计算n天
     * @param date   传入的日期
     * @param oldFormat	传入的日期格式
     * @param isAfter 向后计算ture，向前计算false
     * @param day 计算的天数
     * @param newFormat 返回的日期字符串格式
     * @return 字符串日期
     * @throws Exception
     */
    public static String getDateBeforeOrAfterDay(String date, String oldFormat, boolean isAfter, int day, String newFormat) throws Exception{
    	SimpleDateFormat osdf = new SimpleDateFormat(oldFormat); 
    	SimpleDateFormat nsdf = new SimpleDateFormat(newFormat); 
    	Date oldDate = osdf.parse(date); 
    	Calendar rightNow = Calendar.getInstance(); 
    	rightNow.setTime(oldDate); 
    	if(isAfter)
    		rightNow.add(Calendar.DATE,day);//要加的日期 
    	else
    		rightNow.add(Calendar.DATE,-day);//要减的日期 
    	return nsdf.format(rightNow.getTime());
    }
	
	
	
	
	/**
     * 某月最后一天
     * @param year
     * @param month
     * @param day
     * @param formate
     * @return
     */
    public static String getLastDay(int year,int month,int day,String formate){
    	SimpleDateFormat df = new SimpleDateFormat(formate);
    	Calendar calendar = Calendar.getInstance();
    	calendar.set(year, month, day);
    	calendar.add(Calendar.DAY_OF_MONTH, -1);
    	return df.format(calendar.getTime());
    }
    
	/**
	 * 得到两日期相差几个月 
	 * @param startDate  2013-07-01
	 * @param endDate    2013-09-01
	 * @return  3
	 */
    public static int getMonthDiff(String startDate, String endDate) throws Exception{
        int monthday;
        SimpleDateFormat fmt = new SimpleDateFormat("yyyy-MM-dd");
        Date startDate1 = fmt.parse(startDate);
        Calendar starCal = Calendar.getInstance();
        starCal.setTime(startDate1);
        int sYear  = starCal.get(Calendar.YEAR);
        int sMonth = starCal.get(Calendar.MONTH);
        Date endDate1 = fmt.parse(endDate);
        Calendar endCal = Calendar.getInstance();
        endCal.setTime(endDate1);
        int eYear  = endCal.get(Calendar.YEAR);
        int eMonth = endCal.get(Calendar.MONTH);
        monthday = ((eYear - sYear) * 12 + (eMonth - sMonth));
        return monthday+addMonth;
    }
    
    /**
     * 某个日期的下N个月
     * @return
     */
    public static String getNextMonth_N(String gscstr,int N) throws Exception {
        SimpleDateFormat df = new SimpleDateFormat("yyyy-MM-dd");
        Date date = df.parse(gscstr);
        Calendar calendar = Calendar.getInstance();
        calendar.setTime(date);
        calendar.add(Calendar.MONTH, N);
        
        Date theDate = calendar.getTime();
        String s = df.format(theDate);
        StringBuffer str = new StringBuffer().append(s).append(" 23:59:59");
        return str.toString();


    }
    
    /**
     * 当前日期的下一天
     */
    public static String getNextDay(String gscstr) throws Exception{
    	return getNextDay_N(gscstr,1);
    }
    
    /**
     * 当前日期的下N天
     */
    public static String getNextDay_N(String gscstr,int N) throws Exception{
    	SimpleDateFormat df = new SimpleDateFormat("yyyy-MM-dd");
    	Date date = df.parse(gscstr);
    	Calendar calendar = Calendar.getInstance();
    	calendar.setTime(date);
    	calendar.add(Calendar.DAY_OF_MONTH, N);
    	
    	Date theDate = calendar.getTime();
    	String s = df.format(theDate);
    	StringBuffer str = new StringBuffer().append(s).append(" 00:00:00");
    	return str.toString();
    }
    
    /**
     * 当前日期的上一天
     */
    public static String getForwardDay(String gscstr) throws Exception{
    	SimpleDateFormat df = new SimpleDateFormat("yyyy-MM-dd");
    	Date date = df.parse(gscstr);
    	Calendar calendar = Calendar.getInstance();
    	calendar.setTime(date);
    	calendar.add(Calendar.DAY_OF_MONTH, -1);
    	
    	Date theDate = calendar.getTime();
    	String s = df.format(theDate);
    	StringBuffer str = new StringBuffer().append(s).append(" 00:00:00");
    	return str.toString();
    }
    
    /**
     * 当前日期的下N年
     */
    public static String getNextYear_N(String gscstr,int N) throws Exception{
    	SimpleDateFormat df = new SimpleDateFormat("yyyy-MM-dd");
    	Date date = df.parse(gscstr);
    	Calendar calendar = Calendar.getInstance();
    	calendar.setTime(date);
    	calendar.add(Calendar.YEAR, N);
    	
    	Date theDate = calendar.getTime();
    	String s = df.format(theDate);
    	StringBuffer str = new StringBuffer().append(s).append(" 00:00:00");
    	return str.toString();
    }