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使用Room递归调用getDatabase

android-room persistence android

0

Genaut · 技术社区 · 8 年前

我在活动类中执行getDatabase方法,但是我使用dao从数据库中获取信息,应用程序崩溃。这是我第一次接触Android房间,也许我忘记了一些重要的事情要做。有人能帮我吗?

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;"

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

这就是错误

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$1.run(AsyncTask.java:243)Â 
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1133)Â 
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:607)Â 
        at java.lang.Thread.run(Thread.java:761)

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

3 回复 | 直到 8 年前

1

6

CommonsWare 8 年前

但是我使用dao从数据库中获取信息

这行不通,因为房间还没摆好。或者:

在外面做这个工作 RoomDatabase.Callback
请勿使用 ,而是使用 SupportSQLiteDatabase 作为参数提供给 onOpen() 以及其他回调方法

2

DuDu 7 年前

这是因为 onOpen() getDatabase 打电话。

INSTANCE.soundsDao().deleteAllSounds() ,如果您查看 deleteAllSounds() 在里面 SoundsDao_Impl (Impl生成的文件 Dao s) ,你可以看到它在召唤 __db.beginTransaction() 哪一个会打电话 mOpenHelper.getWritableDatabase() .

Exception 被抛出 getDatabase called recursively .

修复是可以的 实例.soundsDao().deleteAllSounds() https://medium.com/androiddevelopers/7-pro-tips-for-room-fbadea4bfbd1

ioThread {
    INSTANCE.soundsDao().deleteAllSounds()
}

...

private val IO_EXECUTOR = Executors.newSingleThreadExecutor()

/**
 * Utility method to run blocks on a dedicated background thread, used for io/database work.
 */
fun ioThread(f : () -> Unit) {
    IO_EXECUTOR.execute(f)
}

此处引用: https://gist.github.com/florina-muntenescu/697e543652b03d3d2a06703f5d6b44b5

3

1

Moaz Rashad 6 年前

Executors.newSingleThreadExecutor().execute {
    INSTANCE.soundsDao().deleteAllSounds(); 
}

4

0

Nurseyit Tursunkulov 7 年前

我的朋友,我也有类似的问题。但对我来说,问题是我从两个不同的类获取数据库。当从第二个类中删除第二个初始化时,它起作用了。