wsdl2java is a tool included in most Java Web Service Implementation (Sun's, Axis'es etc). The tool is usually released as command line program (bat, sh). Generally speaking, the same tools often released as
ANT tasks too.
To generate java stubs the wsdl file can be downloaded and saved locally, or pointed as accessible resource (URL). The path (or url) to wsdl file goes as a required parameter for tool. Rest of parameters - folder where to place generated java sources, java package for these sources, and a number of params with minor meaning, which help to customize the result.
Given description can be considered as a short description of tool and targeted usage. More detailed information can be reached by calling particular tool (Axis'es or Sun's or other) with help flag or without parameters(by default they usually draw help info).
Pavel Cherkashin - <br />SCJP, SCWCD, SCDJWS, SCBCD, SCEA, ...<br />www.linkedin.com/in/pcherkas