Problem with % signs in key value url parameter pairs

Question

Hi,
Tomcat 5.5.9
Java Version 1.5
I'm having a little difficulty passing a certain key value pair via a URL to the processing component of my web application.
If I submit a value for lets say parameter 'product_name' and that value starts with a % sign then the value is passed to my processing component as 'null' if I remove the % sign the value is correctly received.
Anyone come accross this on a Tomcat server?
The data has to be tagged onto the URL rather than as a form 'Post', as it is used to create and populate a popup window.
Thanks in advance.

Answer 1

So the % is used in URLs to mark certain escape sequences, so when you put it in you value, it thinks that the value is actually an escape sequence, and probably translates poorly on the opposite side.
You will actually need to use the escape sequence for the % sign to get it work correctly. I don't recall the actual escape value, but:
If you use JSTL to put together the URL for you, you shouldn't have a problem, the values will be escapes:
<c:url var="popupAddress" url="http://www.mydomain.com/myapp/mupage.jsp">
  <c:param name="product_name" value="%Whatever"/>
</c:url>
<script type="text/javascript">
  document.open("<c:out value="${popupAddress}"/>","Popup");
</script>