java.lang.IllegalArgumentException with URLDecoder.decode() for %
Asked on July 23, 2014
Hi,
I am using URLDecoder.decode() in my web application. When this methods get % in parameter value,
it throws java.lang.IllegalArgumentException.
How to handle this exception.
Replied on July 24, 2014
Check the below Java doc of URLDecoder.decode()
It does not accept "%x" it means it can not accept values as "%" or "%abcd".
To handle the IllegalArgumentException, we need to check for such condition.
// A trailing, incomplete byte encoding such as
// "%x" will cause an exception to be thrown
if ((i < numChars) && (c=='%'))
throw new IllegalArgumentException(
"URLDecoder: Incomplete trailing escape (%) pattern");
When we send data from browser to server, browser does one time encoding
and request.getParameter() does one time decoding and if output of
request.getParameter() is passed to URLDecoder.decode(), then "%x" values will throw
IllegalArgumentException
