title: Servlet Filter to check the Attachment extension
body: <p>I need to restrict users from attaching files with some extensions for e.g.: bat,exe,bin etc..</p>
  
  <p>For this i believe i will need to write a servlet filter . I am new to servlets ,can someone please guide me how i can achieve this ?</p>
  
  <p>Is using Servlet filter a correct approach ? </p>
  
  <p>Any help highly appreciated.
  Please let me know if any other information is needed from me.</p>