You can try javscript validation some what like this
function checkFileExtension() {
//get the file extension in a variable
var extension = document.FBITT.ffAttachment.value;
var isValid = false;
var strExtensions="";
//alert("ext before while:"+ extension);
//substring
while(extension.indexOf('.') != -1) {
//alert("gkmkc");
//alert(extension.length);
//alert(extension.indexOf('.'));
extension = extension.substring((extension.indexOf('.')+1), extension.length);
//alert("ext :"+ extension);
//alert("ext :"+ extension);
}
//alert("ext after while:"+ extension);
//iterate and valiadte against the arraylist in the formbean
<%
//i hate to do this, but alas.. may i think of a better way given the time...
sg.gov.sco.gebiz.webitt.formbean.itts.FBITT fbFBITT = (sg.gov.sco.gebiz.webitt.formbean.itts.FBITT) request.getSession(false).getAttribute("FBITT");
for(int i=0; i<fbFBITT.getArrValidFileExtensions().size(); i++) {
%>
var validExtensionU = '<%=((
String)fbFBITT.getArrValidFileExtensions().get(i)).toUpperCase()%>';
var validExtensionL = '<%=((String)fbFBITT.getArrValidFileExtensions().get(i)).toLowerCase()%>';
strExtensions = strExtensions + validExtensionL + ", ";
//make this case independent in
java script
//alert(validExtension)
if(extension==validExtensionU || extension == validExtensionL) {
//set isValid to true, though redundant
isValid = true;
}
<% } %>
if(isValid==false) {
alert("Please select a file with one of the following file extension:\n"+strExtensions.substring(0, strExtensions.length-2));
}
//alert("isValid :"+isValid);
return isValid;
} //checkFileExtension-ends
