how to store java list in realm android database

Question

How we can store java list in realm android database. I try to store it by using setter method present in my model, but it doesn't work and I get "Each element of 'value' must be a valid managed object" in exception message.

public void storeNewsList(String categoryId, List<News> newsList) { 
    Realm realm = Realm.getDefaultInstance(); 
    realm.beginTransaction(); 
    NewsList newsListObj = realm.createObject(NewsList.class); 
    newsListObj.setNewsList(new RealmList<>(newsList.toArray(new News[newsList.size()]))); 
    newsListObj.setCategoryId(categoryId); 
    realm.commitTransaction(); 
    realm.close(); 
}

public void storeNewsList(String categoryId, List newsList) { Realm realm = Realm.getDefaultInstance(); realm.beginTransaction(); NewsList newsListObj = realm.createObject(NewsList.class); newsListObj.setNewsList(newsListObj.setNewsList(new RealmList<>(newsList.toArray(new News[newsList.size()])));); newsListObj.setCategoryId(categoryId); realm.commitTransaction(); realm.close(); } — Anil, May 02 '17 at 12:57

EpicPandaForce · Accepted Answer · 2017-05-03T09:18:12.377

14

Replace code with

public void storeNewsList(String categoryId, List<News> newsList) { 
    try(Realm realm = Realm.getDefaultInstance()) { 
        realm.executeTransaction(new Realm.Transaction() {
             @Override
             public void execute(Realm realm) {
                 NewsList newsListObj = new NewsList(); // <-- create unmanaged
                 RealmList<News> _newsList = new RealmList<>();
                 _newsList.addAll(newsList);
                 newsListObj.setNewsList(_newsList); 
                 newsListObj.setCategoryId(categoryId);
                 realm.insert(newsListObj); // <-- insert unmanaged to Realm
             }
        }); 
    }
}

edited May 03 '17 at 09:18

answered May 02 '17 at 14:18

EpicPandaForce

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newsListObj.setNewsList(new RealmList<>(newsList)); getting error unable to resolve constructor. – Anil May 03 '17 at 06:17
ah, well then `addAll()` it is – EpicPandaForce May 03 '17 at 06:27
It work for me with just one correction instead of RealmList _newsList = new RealmList<>(); I need to add RealmList _newsList = new RealmList<>(); – Anil May 03 '17 at 09:03
Do we need to close the realm? Does your solution create a memory leak ? – Dagnogo Jean-François Jan 04 '18 at 16:39
2

Of course, try with resources autocloses Realm instance – EpicPandaForce Jan 04 '18 at 18:21
@EpicPandaForce you're awesome. \m/ – Aks4125 Apr 04 '18 at 07:15
@EpicPandaForce one quick question.can we use `Realm.getDefaultInstance().copyFromRealm(Realm.getDefaultInstance().where(HomeJob.class).findAll()` from multiple threads. Just to avoid error. – Aks4125 Apr 04 '18 at 07:33
1

@Aks4125 god no you're leaking 2 realm instances per a single line O_o – EpicPandaForce Apr 04 '18 at 08:37

score 1 · Answer 2 · answered Apr 04 '18 at 07:18

In case if you're using @PrimaryKey then insertOrUpdate will do the trick

try(Realm realm = Realm.getDefaultInstance()) {
                        realm.executeTransaction(new Realm.Transaction() {
                            @Override
                            public void execute(Realm realm) {
                                 RealmList<News> _newsList = new RealmList<>();
                                _newsList.addAll(myCustomArrayList);
                                realm.insertOrUpdate(_newsList); // <-- insert unmanaged to Realm

                            }
                        });
                    }

how to store java list in realm android database

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