计算时间差函数

/**     * 计算时间差,如果endTime为空则默认当前时间     * @param startTime     * @param endTime     * @param level     * @return     */    public static float dateDiff(Date startTime, Date endTime,String level) {        if(startTime==null){            log.info("dateDiff startTime不能为空");        }        if(StringUtils.isBlank(level)){            level="h";        }        if(endTime==null){            endTime=new Date();        }        // 获得两个时间的毫秒时间差异        float diff = new Long(endTime.getTime() - startTime.getTime()).floatValue();        float result=0;        if (level.equalsIgnoreCase("d")) {            result = diff / (1000 * 24 * 60 * 60);// 计算差多少天            log.info("dateDiff day："+result+",start:"+startTime.toString()+" end:"+endTime.toString());            return result;        } else if (level.equalsIgnoreCase("h")){            result = diff / (1000 * 60 * 60);// 计算差多少小时            log.info("dateDiff hour："+result+",start:"+startTime.toString()+" end:"+endTime.toString());            return result;        }else if (level.equalsIgnoreCase("m")){            result = diff / (1000 * 60);// 计算差多少分钟            log.info("dateDiff min："+result+",start:"+startTime.toString()+" end:"+endTime.toString());            return result;        }else if (level.equalsIgnoreCase("s")){            result = diff / 1000;// 计算差多少秒            log.info("dateDiff sec："+result+",start:"+startTime.toString()+" end:"+endTime.toString());            return result;        }else{            return result;        }    }