in the main class:

        Map<String, String> variables = new HashMap<String, String>();

        variables.put("fooBar", "23");
        variables.put("foo2", "52");

        ..
        ..
        ..

         xl.init(funcLibs, variables)

in the "working" class:

        public class EvaluateInt<Integer> implements Evaluator {

        ...
        ...

        private Map<String, String> variables;

        public void init(List funcLibs, Map variables) {
        initialized = true;
        this.funcLibs = funcLibs;
        this.variables = variables;

        ...


        public interface Evaluator<T extends Object> {

        ...

        public void init(List<FunctionLib<T>> funcLibs, Map<String, T> variables);