JSP getparameter null

How to get the parameter in JSP even if it is null?

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April 22, 2008 at 7:51 PM

Hi friend,

<html>
<title>Date validation</title>
<head>

<script LANGUAGE="JavaScript">





<!-- Begin
function checkdate(objName) {
var datefield = objName;
if (chkdate(objName) == false) {
datefield.select();
alert("That date is invalid. Please try again.");
datefield.focus();
return false;
}
else {
return true;
}
}
function chkdate(objName) {
var strDatestyle = "INDIA"; //United States date style
var strDate;
var strDateArray;
var strDay;
var strMonth;
var strYear;
var intday;
var intMonth;
var intYear;
var booFound = false;
var datefield = objName;
var strSeparatorArray = new Array("-"," ","/",".");
var intElementNr;
var err = 0;
var strMonthArray = new Array(12);
strMonthArray[0] = "Jan";
strMonthArray[1] = "Feb";
strMonthArray[2] = "Mar";
strMonthArray[3] = "Apr";
strMonthArray[4] = "May";
strMonthArray[5] = "Jun";
strMonthArray[6] = "Jul";
strMonthArray[7] = "Aug";
strMonthArray[8] = "Sep";
strMonthArray[9] = "Oct";
strMonthArray[10] = "Nov";
strMonthArray[11] = "Dec";
strDate = datefield.value;
if (strDate.length < 1) {
return true;
}
for (intElementNr = 0; intElementNr < strSeparatorArray.length; intElementNr++) {
if (strDate.indexOf(strSeparatorArray[intElementNr]) != -1) {
strDateArray = strDate.split(strSeparatorArray[intElementNr]);
if (strDateArray.length != 3) {
err = 1;
return false;
}
else {
strDay = strDateArray[0];
strMonth = strDateArray[1];
strYear = strDateArray[2];
}
booFound = true;
}
}
if (booFound == false) {
if (strDate.length>5) {
strDay = strDate.substr(0, 2);
strMonth = strDate.substr(2, 2);
strYear = strDate.substr(4);
}
}
if (strYear.length == 2) {
strYear = '20' + strYear;
}
// US style
if (strDatestyle == "US") {
strTemp = strDay;
strDay = strMonth;
strMonth = strTemp;
}
intday = parseInt(strDay, 10);
if (isNaN(intday)) {
err = 2;
return false;
}
intMonth = parseInt(strMonth, 10);
if (isNaN(intMonth)) {
for (i = 0;i<12;i++) {
if (strMonth.toUpperCase() == strMonthArray[i].toUpperCase()) {
intMonth = i+1;
strMonth = strMonthArray[i];
i = 12;
}
}
if (isNaN(intMonth)) {
err = 3;
return false;
}
}
---------------

April 22, 2008 at 7:51 PM

intYear = parseInt(strYear, 10);
if (isNaN(intYear)) {
err = 4;
return false;
}
if (intMonth>12 || intMonth<1) {
err = 5;
return false;
}
if ((intMonth == 1 || intMonth == 3 || intMonth == 5 || intMonth == 7 || intMonth == 8 || intMonth == 10 || intMonth == 12) && (intday > 31 || intday < 1)) {
err = 6;
return false;
}
if ((intMonth == 4 || intMonth == 6 || intMonth == 9 || intMonth == 11) && (intday > 30 || intday < 1)) {
err = 7;
return false;
}
if (intMonth == 2) {
if (intday < 1) {
err = 8;
return false;
}
if (LeapYear(intYear) == true) {
if (intday > 29) {
err = 9;
return false;
}
}
else {
if (intday > 28) {
err = 10;
return false;
}
}
}
if (strDatestyle == "US") {
datefield.value = strMonthArray[intMonth-1] + " " + intday+" " + strYear;
}
else {
datefield.value = intday + " " + strMonthArray[intMonth-1] + " " + strYear;
}
return true;
}
function LeapYear(intYear) {
if (intYear % 100 == 0) {
if (intYear % 400 == 0) { return true; }
}
else {
if ((intYear % 4) == 0) { return true; }
}
return false;
}
function doDateCheck(from, to) {
if (Date.parse(from.value) <= Date.parse(to.value)) {
alert("The dates are valid.");
}
else {
if (from.value == "" || to.value == "")
alert("Both dates must be entered.");
else
alert("To date must occur after the from date.");
}
}
// End -->
</script>
</HEAD>
-----------------

April 22, 2008 at 8:03 PM

<body>
<form>

<b>Start Date:</b><input type=text name=from onBlur="checkdate(this)" size=20 maxlength=11>
<br/>
<b>End Date:&nbsp&nbsp</b><input type=text name=to onBlur="checkdate(this)" size=20 maxlength=11>

<input type=button name=formatbutton onClick="doDateCheck(this.form.from, this.form.to);" value="Check">

</form>
</body>
</html>