Data usually falls within the category of some known type or format. Most datatypes can be identified by a MIME type. Examples of data items are HTML files, pictures, sound files, video clips, or spreadsheets. The following are commonly used MIME types:
"text/html" for HTML files
"text/plain" for text files
"image/jpeg" for JPEG images
"image/gif" for GIF images
Commands define operations on a specific MIME type. Typical commands are View, Edit and Print. An application provides ways of invoking a command for a specific data item.
In the context of JAF, JavaBeans are Java components that operate on data items. For every combination of MIME type and command, there is a JavaBean that performs the desired command. ...