RegExpInstantiator is a small library related to the handling of regular expressions (regexps). However, instead of using search or match features which are commonly provided by such libraries, two unique features are available in this one: First, it allows to find a valid instance, given a regexp and optionally some constraints on how the instance has to look like. Second, it allows to transform a regexp into XML Schema. RegExpInstantiator is used in XSD4J and Dynvoker internally but is also available separately from here, including complete documentation.

Regular expressions are represented by RegExpExpression, RegExpTerm and RegExpCharacter. The RegExpConstraint class can be used to formulate some constraints. RegExpInstantiator can parse regular expressions (and yield RegExpExpression objects), but it can also try to apply constraints to existing objects by trying to solve the constraints and building up an internal constraints table. Finally, RegExpSchema handles the regexp conversion to XSD.

RegExpInstantiator is currently being provided in source format and as a ready-to-use JAR package. It is licenced under the GNU GPL. The latest version can be found on the download page.

Make sure to consult the API docs before trying to use the library in an application. There's also a graphics explaining the usage scenarios.