How to sort a HashMap and maintain duplicate entries

HashMaps are not meant to be sorted. Anyway: this is how you could sort a HashMap maintaining, at the same time, duplicate values.

public LinkedHashMap sortHashMapByValuesD(HashMap passedMap) {
    List mapKeys = new ArrayList(passedMap.keySet());
    List mapValues = new ArrayList(passedMap.values());
    Collections.sort(mapValues);
    Collections.sort(mapKeys);
        
    LinkedHashMap sortedMap = 
        new LinkedHashMap();
    
    Iterator valueIt = mapValues.iterator();
    while (valueIt.hasNext()) {
        Object val = valueIt.next();
        Iterator keyIt = mapKeys.iterator();
        
        while (keyIt.hasNext()) {
            Object key = keyIt.next();
            String comp1 = passedMap.get(key).toString();
            String comp2 = val.toString();
            
            if (comp1.equals(comp2)){
                passedMap.remove(key);
                mapKeys.remove(key);
                sortedMap.put((String)key, (Double)val);
                break;
            }

        }

    }
    return sortedMap;
}