java日期间相隔年月日计算

    /**
     * 获取date1相距date2多少天， date2>date1
     * @param date1
     * @param date2
     * @return
     * @throws ParseException
     */
    public static int getDaysSpace(String date1,String date2){
        Calendar cal = Calendar.getInstance();
        cal.setTime(getDate(date1, "yyyyMMdd"));
        long time1 = cal.getTimeInMillis();
        cal.setTime(getDate(date2, "yyyyMMdd"));
        long time2 = cal.getTimeInMillis();
        long between_days=(time2-time1)/(1000*3600*24);
        return Integer.parseInt(String.valueOf(between_days));
    }

    /**
     * 获取date1相距date2几个月， date2>date1
     * @param date1
     * @param date2
     * @return
     * @throws ParseException
     */
    public static float getMonthSpace(String date1, String date2){
        float result = 0;
        Calendar c1 = Calendar.getInstance();
        Calendar c2 = Calendar.getInstance();
        c1.setTime(getDate(date1, "yyyyMMdd"));
        c2.setTime(getDate(date2, "yyyyMMdd"));
        if(c2.get(Calendar.DATE) - c1.get(Calendar.DATE) >= 0){
            result = (c2.get(Calendar.YEAR) - c1.get(Calendar.YEAR)) * 12.0f + (c2.get(Calendar.MONTH) - c1.get(Calendar.MONTH)) + (c2.get(Calendar.DATE) - c1.get(Calendar.DATE))/30.0f;
        }else{
            result = (c2.get(Calendar.YEAR) - c1.get(Calendar.YEAR)) * 12.0f + (c2.get(Calendar.MONTH) - c1.get(Calendar.MONTH)) - 1.0f + (c2.get(Calendar.DATE) - c1.get(Calendar.DATE))/30.0f;
        }
        DecimalFormat df = new DecimalFormat("0.00");
        return Float.parseFloat(df.format(result));
    }

    /**
     * 获取date1相距date2几年， date2>date1
     * @param date1
     * @param date2
     * @return
     * @throws ParseException
     */
    public static float getYearSpace(String date1, String date2) {
        DecimalFormat df = new DecimalFormat("0.00");
        return Float.parseFloat(df.format(getMonthSpace(date1, date2)/12.0f));
    }