How to compare two maps by their values

Question

How to compare two maps by their values? I have two maps containing equal values and want to compare them by their values. Here is an example:

    Map a = ne         


        

Answer 1

If you assume that there can be duplicate values the only way to do this is to put the values in lists, sort them and compare the lists viz:

List values1 = new ArrayList(map1.values());
List values2 = new ArrayList(map2.values());
Collections.sort(values1);
Collections.sort(values2);
boolean mapsHaveEqualValues = values1.equals(values2);

If values cannot contain duplicate values then you can either do the above without the sort using sets.