android - 使用 Room 递归调用 getDatabase

Question

当我尝试初始化数据库时遇到错误。我正在使用 Android Room，我想使用 RoomDatabaseBuilder 来执行回调并填充我的数据库。

我在 Activity 类中执行 getDatabase 方法，但随后我使用 dao 从数据库获取信息，应用程序崩溃了。这是我第一次接触 Android Room，也许我忘记了一些重要的事情。有谁可以帮我解决这个问题吗？

数据库类:

static RoomDatabase.Callback rdc = new RoomDatabase.Callback() {

    @Override
    public void onOpen(@NonNull SupportSQLiteDatabase db) {
        super.onOpen(db);
        Log.d(TAG, "Debug: onOpen");

        //Borramos todos los sonidos de la base de datos
        INSTANCE.soundsDao().deleteAllSounds(); // Instance is "private static DatabaseSounds INSTANCE;"

Activity 行崩溃来源:

db = DatabaseSounds.getDatabase(getApplicationContext());
   AsyncTask task = new LoadGridAsyncTask().execute(); **

   private class LoadGridAsyncTask extends AsyncTask<Void, Void, Integer> {

        @Override
        protected Integer doInBackground(Void... voids) {
            //Extraemos el listado de sonidos y los convertimos a DTO
            List<EntitySounds> listSounds = db.soundsDao().getAll(); **** THIS is the line of crash

这是错误

java.lang.RuntimeException: An error occurred while executing doInBackground()
        at android.os.AsyncTask$3.done(AsyncTask.java:325)
        at java.util.concurrent.FutureTask.finishCompletion(FutureTask.java:354)
        at java.util.concurrent.FutureTask.setException(FutureTask.java:223)
        at java.util.concurrent.FutureTask.run(FutureTask.java:242)
        at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:243)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1133)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:607)
        at java.lang.Thread.run(Thread.java:761)
     Caused by: java.lang.IllegalStateException: getDatabase called recursively
        at android.database.sqlite.SQLiteOpenHelper.getDatabaseLocked(SQLiteOpenHelper.java:203)
        at android.database.sqlite.SQLiteOpenHelper.getWritableDatabase(SQLiteOpenHelper.java:163)
        at android.arch.persistence.db.framework.FrameworkSQLiteOpenHelper$OpenHelper.getWritableSupportDatabase(FrameworkSQLiteOpenHelper.java:96)
        at android.arch.persistence.db.framework.FrameworkSQLiteOpenHelper.getWritableDatabase(FrameworkSQLiteOpenHelper.java:54)
        at android.arch.persistence.room.RoomDatabase.compileStatement(RoomDatabase.java:244)
        at android.arch.persistence.room.SharedSQLiteStatement.createNewStatement(SharedSQLiteStatement.java:65)
        at android.arch.persistence.room.SharedSQLiteStatement.getStmt(SharedSQLiteStatement.java:72)
        at android.arch.persistence.room.SharedSQLiteStatement.acquire(SharedSQLiteStatement.java:87)
        at com.genaut.myapp.database.dao.DaoSounds_Impl.deleteAllSounds(DaoSounds_Impl.java:140)
        at com.genaut.myapp.database.DatabaseSounds$1.onOpen(DatabaseSounds.java:57)
        at com.genaut.myapp.database.DatabaseSounds_Impl$1.onOpen(DatabaseSounds_Impl.java:65)
        at android.arch.persistence.room.RoomOpenHelper.onOpen(RoomOpenHelper.java:111)
        at android.arch.persistence.db.framework.FrameworkSQLiteOpenHelper$OpenHelper.onOpen(FrameworkSQLiteOpenHelper.java:149)
        at android.database.sqlite.SQLiteOpenHelper.getDatabaseLocked(SQLiteOpenHelper.java:266)
        at android.database.sqlite.SQLiteOpenHelper.getWritableDatabase(SQLiteOpenHelper.java:163)
        at android.arch.persistence.db.framework.FrameworkSQLiteOpenHelper$OpenHelper.getWritableSupportDatabase(FrameworkSQLiteOpenHelper.java:96)
        at android.arch.persistence.db.framework.FrameworkSQLiteOpenHelper.getWritableDatabase(FrameworkSQLiteOpenHelper.java:54)
        at android.arch.persistence.room.RoomDatabase.query(RoomDatabase.java:233)
        at com.genaut.myapp.database.dao.DaoSounds_Impl.getAll(DaoSounds_Impl.java:155)
        at com.genaut.myapp.Home$LoadGridAsyncTask.doInBackground(Home.java:83)
        at com.genaut.myapp.Home$LoadGridAsyncTask.doInBackground(Home.java:78)
        at android.os.AsyncTask$2.call(AsyncTask.java:305)
        at java.util.concurrent.FutureTask.run(FutureTask.java:237)
        at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:243) 
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1133) 
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:607) 
        at java.lang.Thread.run(Thread.java:761)

这是 Dao 方法:

@Query("SELECT * FROM entitysounds")
    List<EntitySounds> getAll();

 

Answer 1

but then I use the dao to get info from database

这不起作用，因为房间尚未设置。要么:

• 在 RoomDatabase.Callback 之外执行此工作，或者

• 不要在 RoomDatabase.Callback 内部使用 Room，而是使用作为 onOpen() 参数提供的 SupportSQLiteDatabase 和其他回调方法