Find duplicate values in Java Map?

Example:

Map<Object, Object> map = new HashMap<Object, Object>();
map.put(1,2);
map.put(3,4);
map.put(2,2);
map.put(5,3);

Set<Object> uniqueValues = new HashSet<Object>(map.values());

System.out.println(uniqueValues);

Output:

[2, 3, 4]

Try out this code

private boolean hasDuplicates(Map<Integer, List<String>> datamap){
boolean status = false;


    Set valueset=new HashSet(datamap.values());

    if(datamap.values().size()!=valueset.size()){
    status=true;
    }
    else{
    status = false;
    }


    return status;

}

A simple solution would be to compare the size of your values list with your values set.

// pseudo-code
List<T> valuesList = map.values();
Set<T> valuesSet = new HashSet<T>(map.values);
// check size of both collections; if unequal, you have duplicates