Java + programming a class

Hello, + I need help programming a class in a project; not the whole project! + Project: it is about "Grouping of variants of the different historical names of cities". + My task in this project is: to program a class ('Regex') in Java, where it can found using regular expressions (User Input) a certain combination of characters (about city names). -> You don't have to think up the rules (regular expresiones) yourself. -> The users of the program are the ones who must think up the rules (regular expresiones) themselves. + The other classes in the project important for Regex are: > App: where the 'main method' is, > DBHandler: it is where the database is. +you can use any library, class or project on the internet (parser generators, regular expression matchers, etc), just attach the reference. + If you are interested, I can describe everything in more detail!