Ello there,
I'm trying to assign the value of a javascript variable to a java variable. But I don't have clue how to do this? Say for example I have this:
<html>
<head>
<script type="text/javascript">
function return variable(){
var a = "hello";
return a;
}
</script>
</head>
<body>
<%
//The java code
String b = //how do I get that javascript variable here?
%>
</body>
</html>
This question is related to
java
javascript
jsp
variables
As JavaScript is client side and JSP is Server side.
So Javascript does not execute until it gets to the browser, But Java executes on the server. So, Java does not know the value of the JavaScript variable.
However you assign value of Java variable to JavaScript variable.
I think there's no way to do that, unless you pass the value of the JavaScript var on the URL, but it's a ugly workaround.
You need to read something about a JSP's lifecycle. Try this: http://en.wikipedia.org/wiki/File:JSPLife.png
JavaScript runs on the client, but in order to change the jsp, you need access to the server. This can be done through Ajax(http://en.wikipedia.org/wiki/Ajax_%28programming%29).
Here are some Ajax-related links: http://www.openjs.com/articles/ajax_xmlhttp_using_post.php
http://www.w3schools.com/ajax/tryit.asp?filename=tryajax_first
you cant do it.. because jsp is compiled and converted into html server side whereas javascript is executed on client side. you may set the value to a hidden html element and send to servlet in request just in case you want to use for further
The answer is You can't. Java (in your case JSP) is a server-side scripting language, which means that it is compiled and executed before all javascript code. You can assign javascript variables to JSP variables but not the other way around. If possible, you can have the variable appear in a QueryString or pass it via a form (through a hidden field), post it and extract the variable through JSP that way. But this would require resubmitting the page.
Hope this helps.
JavaScript is fired on client side and JSP is on server-side. So I can say that it is impossible.
Source: Stackoverflow.com
