package junitparams.converters; public class NullableConverter implements Converter{ private String nullIdentifier; public void initialize(Nullable annotation) { nullIdentifier = annotation.nullIdentifier() == null ? "null" : annotation.nullIdentifier(); } public String convert(Object param) throws ConversionFailedException { if(param instanceof String && ((String)param).trim().equalsIgnoreCase(nullIdentifier)){ return null; } return (String)param; } }