Summary
SAX can be used to support a pipe-and-filter architecture through the use of SAX filters that allow handlers to be linked in a chain and perform staged processing for an application. By focusing on SAX handlers that do simple things, you can compose more complex and varied applications by arranging and rearranging individual filters.
StAX, a simple pull parser for XML, puts the application in control of when parsing occurs and how much of an XML document needs to be read. Rather than one large API, StAX supports two APIs, the lean and mean cursor API and the iterator API that delivers XMLEvents to an application.