RealmObjectQuery.java

package com.github.yatatsu.repository;

import io.realm.RealmObject;
import io.realm.RealmQuery;

public interface RealmObjectQuery<T extends RealmObject> {
  T apply(RealmQuery<T> query);
}

RealmRepository.java

package com.github.yatatsu.repository;

import io.realm.Realm;
import io.realm.RealmConfiguration;
import io.realm.RealmObject;
import io.realm.RealmResults;
import java.util.List;
import rx.Observable;

public class RealmRepository<T extends RealmObject>  {

  private final RealmConfiguration configuration;
  private final Realm realm;
  private final Class<T> clazz;

  public RealmRepository(RealmConfiguration configuration, Class<T> clazz) {
    this.configuration = configuration;
    this.clazz = clazz;
    this.realm = Realm.getInstance(configuration);
  }

  public void close() {
    realm.close();
  }

  public void command(Realm.Transaction transaction) {
    Realm realm = Realm.getInstance(configuration);
    try {
      realm.executeTransaction(transaction);
    } finally {
      realm.close();
    }
  }

  public T queryOne(RealmObjectQuery<T> query) {
    return query.apply(realm.where(clazz));
  }

  public Observable<T> observeQueryOne(RealmObjectQuery<T> query) {
    return query.apply(realm.where(clazz)).<T>asObservable().filter(RealmObject::isLoaded);
  }

  public List<T> query(RealmResultsQuery<T> query) {
    return query.apply(realm.where(clazz));
  }

  public Observable<RealmResults<T>> observeQuery(RealmResultsQuery<T> query) {
    return query.apply(realm.where(clazz)).<T>asObservable().filter(RealmResults::isLoaded);
  }

  public Observable<Void> observeCommand(Realm.Transaction transaction) {
    return Observable.<Void>create(subscriber -> {
      Realm realm = Realm.getInstance(configuration);
      try {
        realm.executeTransaction(transaction);
        subscriber.onNext(null);
        subscriber.onCompleted();
      } catch (Exception e) {
        subscriber.onError(e);
      } finally {
        realm.close();
      }
    });
  }
}

RealmResultsQuery.java

package com.github.yatatsu.repository;

import io.realm.RealmObject;
import io.realm.RealmQuery;
import io.realm.RealmResults;

public interface RealmResultsQuery<T extends RealmObject> {
  RealmResults<T> apply(RealmQuery<T> query);
}