How do i sort Realm Results list alphabetically in android?

Question

I have one realm list and i want to sort the list alphabetically.

Collections.sort(contacts, new java.util.Comparator<Contacts>() {
        @Override
        public int compare(Contacts l1, Contacts l2) {
            String s1 = l1.getName();
            String s2 = l2.getName();

            return s1.compareToIgnoreCase(s2);
        }
 });

But this logic not woking i am posting crash report below, please kindly go through it.

java.lang.UnsupportedOperationException: Replacing and element is not supported.
at io.realm.RealmResults$RealmResultsListIterator.set(RealmResults.java:826
at io.realm.RealmResults$RealmResultsListIterator.set(RealmResults.java:757)at java.util.Collections.sort(Collections.java:1909)

Please kindly go through my post and suggest me some solution.

Answer 1

Sorting in Realm is pretty straight forward.

Here is an example:

Let's assume you want to sort the contact list by name, you should sort it when your querying the results, you will get the results already sorted for you.

There are multiple ways to achieve this

Example:

1) Simple and Recommended way:

// for sorting ascending
RealmResults<Contacts> result = realm.where(Contacts.class).findAllSorted("name");

// sort in descending order
RealmResults<Contacts> result = realm.where(Contacts.class).findAllSorted("name", Sort.DESCENDING); 

Updated since realm 5.0.0

1) Simple and Recommended way:

// for sorting ascending, Note that the Sort.ASCENDING value is the default if you don't specify the order
RealmResults<Contacts> result = realm.where(Contacts.class).sort("name").findAll();

// sort in descending order
RealmResults<Contacts> result = realm.where(Contacts.class).sort("name", Sort. DESCENDING).findAll();

2) for unsorted results

If you are getting unsorted results you can sort them anywhere this way.

RealmResults<Contacts> result = realm.where(Contacts.class).findAll();
result = result.sort("name"); // for sorting ascending

// and if you want to sort in descending order
result = result.sort("name", Sort.DESCENDING);

Have a look here you will find very detailed examples about Realm querying, sorting and other useful usage.