Sorting alphabetically type of hashmap <string,string> ANDROID

Question

After implementing the Hashmap I realized that it was not sorted alphabetically so now I wanted to know if there's another map that sorts the files for me? I tried using the code above but it says that I can't use sort in my listview type

 public ArrayList<HashMap<String, String>> songsList =
     new ArrayList<HashMap<String, String>>();

Collections.sort(songsList, new Comparator<String>() {
                        @Override
                        public int compare(String s1, String s2) {
                            return s1.compareToIgnoreCase(s2);
                        }
                    });

you can't use a Comparator<String> on HashMap, because HashMap is not String. (you need a Comparator<HashMap<String, String>>) — njzk2
– njzk2, Commented Jul 3, 2014 at 13:30
public List<Map<String, String>> songsList = new ArrayList<HashMap<String, String>>(); — EpicPandaForce
– EpicPandaForce, Commented Jul 4, 2014 at 10:46

Ilario · Accepted Answer · 2017-05-22 11:59:41Z

2

EDIT -

You can just use the following -

    Collections.sort(songsList,new Comparator<HashMap<String,String>>(){
public int compare(HashMap<String,String> mapping1,
                    HashMap<String,String> mapping2){
    return mapping1.get("KEY").compareToIgnoreCase(mapping2.get("KEY"));
}

NOTE: Replace KEY with your key.

edited May 22, 2017 at 11:59

Ilario

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answered Jul 4, 2014 at 10:27

sjain

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Comments

Michael Kohne · Accepted Answer · 2014-07-05 11:47:49Z

to store your data sorted you could also use the Sorted Map. then you should have no more problems with sorting the Map.

Greetings.

--- EDIT ---
SortedMap is an Interface, which is implemented by TreeMap. So if you want to use a custom Comparator you can easily implement SortedMap. As an minimal sample (with a treemap):

private static List<Map<String, String>> list = new ArrayList<Map<String, String>>();

public static void main(final String[] args) {

    for(int i = 0; i < 5; i++){
        Map<String, String> map = new TreeMap<String, String>();
        map.put("A", "a");
        map.put("D", "d");
        map.put("B", "b");
        map.put("C", "c");
        list.add(map);
    }

    for (Map<String, String> map : list){
        for (String element : map.values()) {
            System.out.println(element);
        }
    }

}

To implement a SortedMap by yourself take a look at: this

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