Strategy for remove nulls from string parameter values?

Question

I've got a problem where my PostgreSQL database won't store a String that contains a null charcter, and I'm trying to figure out the best place to sanitize the parameter. Your advice is appreciated.

If it were a one-off issue, I'd handle it in the validate() method of the action, but in this case, I feel comfortable declaring that no String parameters in my app should ever contain nulls (or control characters) in their value.

Do you have recommendations about the best place to reject paramters containing nulls app-wide? A normal Java Filter, or perhaps a Struts Interceptor (subclass ParametersInterceptor to create ParameterValueInterceptor)? Or maybe I should sub-class String (ew) and then make my own StrutsTypeConverter? (that last one feels dirty and would require many changes).

This problem came up while attempting to log a message to the database about a login failure for a user that was provided like this:

http://myserver.com/myapp/login?user=%00

I'd rather just pretend that the String excluded that 0x00 character, and was "null".

Answer 1

Cleaning parameter values is perfect for an interceptor, and it's pretty easy to do.

For example, we had interceptors that removed trailing spaces, HTML-safed input, etc.

A filter would work as well, but I tend to use S2-specific artifacts when the entire system is S2.