Gens.java

package com.valbaca;

import java.util.ArrayList;
import java.util.Date;
import java.util.List;

public class Gens {
    public static void main(String[] args) {
        List<Class> classes = new ArrayList<>();
        classes.add(String.class);
        classes.add(Date.class);
        List things = new ArrayList();
        things.add("foo");
        things.add(new Date());
        for (Class clazz : classes) {
            List list = new ArrayList();
            for (Object something : things) {
                if (clazz.isInstance(something)) list.add(something);
            }
            System.out.print(clazz.getSimpleName());
            System.out.print(list);
            System.out.println();
        }
    }

}