Sorting a Map by key using values from another Map

Question

I know there are a lot of similar questions, but I think my case is quite special, and I haven't really found a proper answer that helps me, so here it goes.

I have a Map> with the Integer being a kind of grouping by type and the Strings list being the elements in that type. Each element in a type can have an order value assigned to it (which is not saved in the List by default), so I've made a Map> which consists of the type as key and an element order list as values.

I want to sort the 1st Map by keys, but the values of those keys should be the lowest value from the List for the same key in the 2nd Map. I'm trying to do this by using Collections.sort() with a custom Comparator, but I'm a bit lost as to how exactly to achieve that. Here's the unfinished Comparator code:

 private class sortComparator implements Comparator {

    private Map> grouped = null;
    private Map> sortOrder = null;

    public sortComparator(Map> grouped, Map> sortOrder){
        this.grouped = grouped;
        this.sortOrder = sortOrder;
    }

    @Override
    public int compare(Object o1, Object o2) {

        return 0;
    }
    //get the lowest value from the values connected to a key
    private Integer sortGroups(Map> sortOrder, Integer key){
        List calcTypeOrder = sortOrder.get(key);
        Iterator orderIterator = calcTypeOrder.iterator();
        Integer firstElement;

        Collections.sort(calcTypeOrder);
        if (orderIterator.hasNext()){
            firstElement = (Integer)orderIterator.next();
        } else firstElement = 0;
        return firstElement;
    }
}

I'm quite uncertain how exactly to procede or if I'm even on the right track. I hope I was able to explain what I'm trying to do.
EDIT: More explanations as requested:

Map> grouped
//Map>
//consists of elements, which look like this
Map.EntrySet<13, List

Syam S · Accepted Answer

This should be simple. Just create a custom comparator and refer to the sort order list. For example the sortMap method will do what you are looking for.

import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.HashMap;
import java.util.LinkedHashMap;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;


public class MapSorter2 {

    public static void main(String[] args) {
        Map> grouped = new HashMap>();
        grouped.put(13, new ArrayList() {{ add("Template 1"); add("Template 2"); }});
        grouped.put(24, new ArrayList() {{ add("Something"); add("Something Else"); }});
        grouped.put(1, new ArrayList() {{ add("Example"); add("Example"); add("Example"); }});
        grouped.put(35, new ArrayList() {{ add("More Things"); }});

        Map> sorted = new HashMap>();
        sorted.put(13, new ArrayList() {{ add(3); add(4); }});
        sorted.put(24, new ArrayList() {{ add(1); add(2); }});
        sorted.put(1, new ArrayList() {{ add(6); add(7); add(8); }});
        sorted.put(35, new ArrayList() {{ add(5); }});

        Map> sortedGrouped = sortMap(grouped, sorted);
        System.out.println(sortedGrouped);
    }

    private static Map> sortMap(
            Map> unsortedMap, Map> sortOrder) {

        List>> list = new LinkedList>>(
                unsortedMap.entrySet());

        Collections.sort(list,
                new Comparator>>() {

                    @Override
                    public int compare(Entry> o1,
                            Entry> o2) {
                        Integer key1 = o1.getKey();
                        Integer key2 = o2.getKey();
                        Integer sortObj1 = sortOrder.get(key1).get(0);
                        Integer sortObj2 = sortOrder.get(key2).get(0);
                        return sortObj1.compareTo(sortObj2);
                    }
                });

        Map> sortedMap = new LinkedHashMap>();
        for(Entry> item : list){
            sortedMap.put(item.getKey(), item.getValue());
        }
        return sortedMap;
    }

}

Sorting a Map by key using values from another Map

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