public class ClientDemo { private class MyFilter implements Filter{ private String filterInput; public MyFilter(String input){ this.filterInput = input; } @Override public String getParameters() { return null; } @Override public int currentLength() { return this.filterInput.length(); } } public void testValidators(){ ValidatorFactory factory = new ValidatorFactory(); Validator v = factory.getFilterValidator(new MyFilter("filter string goes here...")); v.validate(); } } }