Hey guys working on some form validation on our jsp page.
I have alert boxes coming up when you enter no value or a non numeric value in the capacity field. But after clicking “OK” the page is redirected to an error:
HTTP Status 500 - For input string: ""
OR when entering “a” in the capacity field
HTTP Status 500 - For input string: "a"
How would I reload the page instead of taking me to the error page?
I have already tried many in built Javascript functions but still directed to the error page, like location.reload() etc.
<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
pageEncoding="ISO-8859-1"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>Mars University Lab System</title>
<link rel="stylesheet" href="style.css" type="text/css" media="screen">
</head>
<body>
<jsp:include page="headerLecturer.jsp"/>
<script>
function chkNumeric(strString)
// check for valid numeric strings
{
var strValidChars = "0123456789.-";
var strChar;
var blnResult = true;
if (strString.length == 0) return false;
// test strString consists of valid characters listed above
for (i = 0; i < strString.length && blnResult == true; i++)
{
strChar = strString.charAt(i);
if (strValidChars.indexOf(strChar) == -1)
{
blnResult = false;
}
}
return blnResult;
}
function validateForm()
{
var capacity=document.forms["createLabs"]["capacity"].value;
var day=document.forms["createLabs"]["day"].value;
var time=document.forms["createLabs"]["time"].value;
var room=document.forms["createLabs"]["room"].value;
if (capacity==null || capacity=="")
{
alert("Capacity must be filled out");
document.createLabs.capacity.focus();
return false;
}
else if(day==null || day=="")
{
alert("Day must be filled out");
document.createLabs.day.focus();
return false;
}
else if(time==null || time=="")
{
alert("Time must be filled out");
document.createLabs.time.focus();
return false;
}
else if(room==null || room=="")
{
alert("Room must be filled out");
document.createLabs.room.focus();
return false;
}
else if (chkNumeric(document.createLabs.capacity.value) == false)
{
alert("Please check - non numeric value!");
document.createLabs.room.focus();
return false;
}
else if (chkNumeric(document.createLabs.room.value) == false)
{
alert("Please check - non numeric value!");
document.createLabs.room.focus();
return false;
}
var link2 = document.getElementById('submit');
link2.onclick = function ()
{
if( confirm("Please fill in all the required fields") )
{
window.location.reload();
}
return false;
}
}
</script>
<tr>
<td>
</td>
</tr>
<tr>
<td>
<div id = "centrecontent">
<br>
<h3>Create Labs</h3>
<%String[] list1 = (String[])request.getAttribute("res1"); %>
<%String[] list2 = (String[])request.getAttribute("res2"); %>
<form name ="createLabs" ACTION="CreateLab" method="post">
Subject: <select name="subject_id">
<%
for(int i=0; i<list1.length; i++)
{
//for(int m=0; m<list2.length;i++)
//{
out.println("<option value="+list1[i]+"> "+list2[i]+" </option>");
//}
out.println("list1:"+list1[0]);
}
%>
</select><br><br>
Capacity: <input type="text" name="capacity"/><br /><br>
<input type="hidden" name="spots_left"/>
Day: <input type="text" name="day"/><br /><br>
Time (HH:MM:SS): <input type="time" name="time"/><br /><br>
Room: <input type="text" name="room"/><br /><br>
<input type=SUBMIT value="Submit" name="Submit" onClick="validateForm()" />
</form>
</div>
<jsp:include page="footer.jsp"/>
</body>
</html>
The problem is comming from the server side, so the problem is with the validation
in javascript functions
I changed validateForm but did not check.
Maybe it will help
In addition you need to put validateForm trigger for “onsubmit” event