Web fragments are xml files that will have part of the configurations of a web.xml. There can be many web fragments, and when the application is deployed container will combine all the fragments and will treat it like a single web.xml. Similar to annotations, now developers can write web fragments for their modules and application assemblers would not have to add them to the web.xml file. We can override annotation behavior with a web fragment or web.xml.

Annotations were introduced to reduce the burden of Application assemblers who would otherwise have to combine every developer’s configuration details into the web.xml file. Thus annotations allow for pluggability of the code by allowing developers to specify configurations on their own classes and hence application assemblers would not have to add them to the web.xml file. We can still use web.xml to override any of the configuration given by an annotation.

Methods related to getPart will throw IOException if an I/O error occurred during the retrieval of the Part components of this request, ServletException if this request is not of type multipart/form-data or IllegalStateException if the request body is larger than maxRequestSize, or any Part in the request is larger than maxFileSize.

Java EE introduced built in support for handling multipart MIME file uploads in Servlet 3.0 (Java EE 6). If you enable this functionality on a servlet, the container will make additional methods available on an HttpServletRequest to get all parts available on a request and also to get one of those parts passing in its name. We will see a demo of the multipart file upload in Servlet 3.0 using multipart config.

Java EE introduced built in support for handling multipart MIME file uploads in Servlet 3.0 (Java EE 6). Web servers based on PHP and ASP.NET have provided this functionality for some time now, saving having to use other third party libraries for the multipart “heavy lifting”.