Web Application Deployment Descriptor - MIME Mappings

Use this panel to configure valid document types for your web application. In addition to the standard HTML and JSP document types, you may want to configure your web application to use other types of information. You add the document's MIME type to this panel to inform the web server which MIME types are associated with specific file name extensions in your web application. The web browser that runs your web application can then examine the MIME type returned by the server for a given request and determine how to handle the data contained in the response.

The subelement <mime-mapping> is not a required element of the web.xml deployment descriptor definition.

MIME Mappings
Displays the list of web application MIME types that you have associated with particular document file name extensions, including the default html and txt types.
Add
Click to configure a new MIME-type mapping definition for your web application.
Delete
Click to remove an existing mapping definition that you select from the MIME mappings list.
Extension
(Required) Enter the file name extension of the document type you want to map to a particular MIME type for your web application. For example, pdf. This field corresponds to the <extension> tag of the <mime-mapping> subelement.
MIME Type
(Required) Enter the document MIME type that you want to map to the specified file name extension. For example, application/pdf for Adobe's Portable Document Format. This field corresponds to the <mime-type> tag of the <mime-mapping> subelement. Note, the official registry of Internet MIME types is managed by the Internet Assigned Numbers Authority (IANA):
http://www.iana.org

You can also refer to the following reference for assistance: