Move several classes to other packages.

app/src/main/java/SubredditDatabase/SubredditDao.java

@@ -0,0 +1,25 @@
+package SubredditDatabase;
+
+import android.arch.lifecycle.LiveData;
+import android.arch.persistence.room.Dao;
+import android.arch.persistence.room.Insert;
+import android.arch.persistence.room.OnConflictStrategy;
+import android.arch.persistence.room.Query;
+
+@Dao
+public interface SubredditDao {
+    @Insert(onConflict = OnConflictStrategy.REPLACE)
+    void insert(SubredditData SubredditData);
+
+    @Query("DELETE FROM subreddits")
+    void deleteAllSubreddits();
+
+    @Query("SELECT * from subreddits WHERE id = :id")
+    LiveData<SubredditData> getSubredditLiveDataById(String id);
+
+    @Query("SELECT * from subreddits WHERE name = :namePrefixed")
+    LiveData<SubredditData> getSubredditLiveDataByNamePrefixed(String namePrefixed);
+
+    @Query("SELECT * from subreddits WHERE name = :namePrefixed")
+    SubredditData getSubredditData(String namePrefixed);
+}

app/src/main/java/SubredditDatabase/SubredditData.java

@@ -0,0 +1,63 @@
+package SubredditDatabase;
+
+import android.arch.persistence.room.ColumnInfo;
+import android.arch.persistence.room.Entity;
+import android.arch.persistence.room.PrimaryKey;
+import android.support.annotation.NonNull;
+
+@Entity(tableName = "subreddits")
+public class SubredditData {
+    @PrimaryKey
+    @NonNull
+    @ColumnInfo(name = "id")
+    private String id;
+
+    @ColumnInfo(name = "name")
+    private String name;
+
+    @ColumnInfo(name = "icon_url")
+    private String iconUrl;
+
+    @ColumnInfo(name = "banner_url")
+    private String bannerUrl;
+
+    @ColumnInfo(name = "description")
+    private String description;
+
+    @ColumnInfo(name = "subscribers_count")
+    private int nSubscribers;
+
+    public SubredditData(@NonNull String id, String name, String iconUrl, String bannerUrl, String description, int nSubscribers) {
+        this.id = id;
+        this.name = name;
+        this.iconUrl = iconUrl;
+        this.bannerUrl = bannerUrl;
+        this.description = description;
+        this.nSubscribers = nSubscribers;
+    }
+
+    @NonNull
+    public String getId() {
+        return id;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public String getIconUrl() {
+        return iconUrl;
+    }
+
+    public String getBannerUrl() {
+        return bannerUrl;
+    }
+
+    public String getDescription() {
+        return description;
+    }
+
+    public int getNSubscribers() {
+        return nSubscribers;
+    }
+}

app/src/main/java/SubredditDatabase/SubredditRepository.java

@@ -0,0 +1,43 @@
+package SubredditDatabase;
+
+import android.app.Application;
+import android.arch.lifecycle.LiveData;
+import android.os.AsyncTask;
+
+public class SubredditRepository {
+    private SubredditDao mSubredditDao;
+    private LiveData<SubredditData> mSubredditLiveData;
+
+    SubredditRepository(Application application, String value, boolean isId) {
+        SubredditRoomDatabase db = SubredditRoomDatabase.getDatabase(application);
+        mSubredditDao = db.subredditDao();
+        if(isId) {
+            mSubredditLiveData = mSubredditDao.getSubredditLiveDataById(value);
+        } else {
+            mSubredditLiveData = mSubredditDao.getSubredditLiveDataByNamePrefixed(value);
+        }
+    }
+
+    LiveData<SubredditData> getSubredditLiveData() {
+        return mSubredditLiveData;
+    }
+
+    public void insert(SubredditData subredditData) {
+        new SubredditRepository.insertAsyncTask(mSubredditDao).execute(subredditData);
+    }
+
+    private static class insertAsyncTask extends AsyncTask<SubredditData, Void, Void> {
+
+        private SubredditDao mAsyncTaskDao;
+
+        insertAsyncTask(SubredditDao dao) {
+            mAsyncTaskDao = dao;
+        }
+
+        @Override
+        protected Void doInBackground(final SubredditData... params) {
+            mAsyncTaskDao.insert(params[0]);
+            return null;
+        }
+    }
+}

app/src/main/java/SubredditDatabase/SubredditRoomDatabase.java

@@ -0,0 +1,26 @@
+package SubredditDatabase;
+
+import android.arch.persistence.room.Database;
+import android.arch.persistence.room.Room;
+import android.arch.persistence.room.RoomDatabase;
+import android.content.Context;
+
+@Database(entities = {SubredditData.class}, version = 1)
+public abstract class SubredditRoomDatabase extends RoomDatabase{
+    private static SubredditRoomDatabase INSTANCE;
+
+    public abstract SubredditDao subredditDao();
+
+    public static SubredditRoomDatabase getDatabase(final Context context) {
+        if(INSTANCE == null) {
+            synchronized (SubredditRoomDatabase.class) {
+                if(INSTANCE == null) {
+                    INSTANCE = Room.databaseBuilder(context.getApplicationContext(),
+                            SubredditRoomDatabase.class, "subreddits")
+                            .build();
+                }
+            }
+        }
+        return INSTANCE;
+    }
+}

app/src/main/java/SubredditDatabase/SubredditViewModel.java

@@ -0,0 +1,48 @@
+package SubredditDatabase;
+
+import android.app.Application;
+import android.arch.lifecycle.AndroidViewModel;
+import android.arch.lifecycle.LiveData;
+import android.arch.lifecycle.ViewModel;
+import android.arch.lifecycle.ViewModelProvider;
+import android.support.annotation.NonNull;
+
+public class SubredditViewModel extends AndroidViewModel {
+    private SubredditRepository mSubredditRepository;
+    private LiveData<SubredditData> mSubredditLiveData;
+
+    SubredditViewModel(Application application, String id, boolean isId) {
+        super(application);
+        mSubredditRepository = new SubredditRepository(application, id, isId);
+        mSubredditLiveData = mSubredditRepository.getSubredditLiveData();
+    }
+
+    public LiveData<SubredditData> getSubredditLiveData() {
+        return mSubredditLiveData;
+    }
+
+    public void insert(SubredditData subredditData) {
+        mSubredditRepository.insert(subredditData);
+    }
+
+    public static class Factory extends ViewModelProvider.NewInstanceFactory {
+
+        @NonNull
+        private final Application mApplication;
+
+        private final String value;
+        private final boolean isId;
+
+        public Factory(@NonNull Application application, String value, boolean isId) {
+            mApplication = application;
+            this.value = value;
+            this.isId = isId;
+        }
+
+        @Override
+        public <T extends ViewModel> T create(Class<T> modelClass) {
+            //noinspection unchecked
+            return (T) new SubredditViewModel(mApplication, value, isId);
+        }
+    }
+}