自动生成日期的差值.....

自动生成两个日期的差值
后台的验证:String stayDuration = visaInformationVO.get("regStayDuration");
String dateFromStr = visaInformationVO.get("registerDateFrom");
String dateToStr = visaInformationVO.get("registerDateTo");

if(!VisaUtil.checkIsEmptyStr(dateFromStr) && !VisaUtil.checkIsEmptyStr(dateToStr) && VisaUtil.checkIsEmptyStr(stayDuration))
{

SimpleDateFormat sf = new SimpleDateFormat(ApplicationConstants.DATE_FORMAT);
try
{
Date dateFrom = sf.parse(dateFromStr);
    Date dateTo = sf.parse(dateToStr);
    long fromTime = dateFrom.getTime();
    long toTime = dateTo.getTime();
   
    long stayTime = ((toTime-fromTime)/(24*60*60*1000))+1;
    stayDuration = ""+stayTime;
}
catch (ParseException e)
{
HW_Log4j.error("ParseException", "ParseException");
}
}




前台的js代码:
function accoutStayDuration(){
var registerDateFromStart=document.getElementById("registerDateFrom").value;
var registerDateToEnd=document.getElementById("registerDateTo").value;

if(''!= registerDateFromStart && registerDateFromStart != undefined && ''!= registerDateToEnd && registerDateToEnd != undefined){
               
var start=toDate(registerDateFromStart);
var end=toDate(registerDateToEnd);
if(!checkStartDateAndEndDate('<bean:message key="view.visaValidityPeriod"/> From',get('registerDateFrom'),'<bean:message key="view.visaValidityPeriod"/> To',get('registerDateTo'))){
get('regStayDuration').value='';
return false;
}
else{
get('regStayDuration').value=parseInt((end-start)/1000/3600/24)+1;

}
}
    }
    function toDate(dateString){
var dateTo = new Date();
var dateArr = dateString.split('-');
dateTo.setFullYear(dateArr[0]);
dateTo.setMonth(dateArr[1]-1);
dateTo.setDate(dateArr[2]);
return dateTo;
}