1

First of all, all similar postings here didn't help.

In an AsyncTask I check if the app startup is the very first startup at all, that means I check if there is a database at all. I want to do that by query from a table. This is what is being executed:

@Override
public List<Entity> loadAll(Entity markerEntity)
{
    Log.i(TAG, "trying to load all entities of type " + markerEntity.getTable());

    List<Entity> results = new LinkedList<Entity>();

    SQLiteDatabase db = defaultSQLiteOpenHelper.getWritableDatabase();

    Cursor cursor = db.query(markerEntity.getTable(), markerEntity.getAllColumns(), null, null, null, null, null);    
    cursor.moveToFirst();

    while (!cursor.isAfterLast())
    {
        Entity result = markerEntity.createNewInstance(cursor);
        results.add(result);

        cursor.moveToNext();
    }

    db.close();

    return results;
}

The crash with IllegalArgumentException: database not open happens on this line.

SQLiteDatabase db = defaultSQLiteOpenHelper.getWritableDatabase();

It happens exactly on the method (see below) createAllTables.

The documentation says:

Create and/or open a database that will be used for reading and writing. The first time this is called, the database will be opened and onCreate(SQLiteDatabase), onUpgrade(SQLiteDatabase, int, int) and/or onOpen(SQLiteDatabase) will be called.

In my opinion it should execute my DefaultSQLiteOpenhelper and create all database tables, but it doesn't do that:

public class DefaultSQLiteOpenHelper extends SQLiteOpenHelper implements ISQLiteOpenHelper
{
    private static final String TAG = DefaultSQLiteOpenHelper.class.getSimpleName();

    private static final String DATABASE_NAME = "MY_DATABASE";
    private static final int DATABASE_VERSION = 1;

    @Inject
    public DefaultSQLiteOpenHelper(Context context)
    {
        super(context, DATABASE_NAME, null, DATABASE_VERSION);
    }

    //is called by the framework if the database doesn't exist
    @Override
    public void onCreate(SQLiteDatabase db)
    {
        Log.i(TAG, "no database found. Generating new database...");

        createAllTables(db);    
    }

    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion)
    {
         Log.w(TAG, "Upgrading database from version " + oldVersion + " to " + newVersion);
//       db.execSQL("DROP TABLE IF EXISTS " + TABLE_COMMENTS); ///TODO when upgrade
//       onCreate(db);
    }

    //The order must not be changed because sqlite doesn't allow
    //table modification. That means one cannot add constraints afterwards
    //which results in creating tables in a specific order
    private final void createAllTables(SQLiteDatabase db)
    {
        db.beginTransaction();

        //create lookups at first
        db.execSQL(TableFactory.createUsage());
        db.execSQL(TableFactory.createLanguage());

        db.execSQL(TableFactory.createAccount());
        db.execSQL(TableFactory.createPreferences());
        db.execSQL(TableFactory.createLanguageUsageRel());
        db.execSQL(TableFactory.createPantry());
        db.execSQL(TableFactory.createProduct());

        //populate lookups
        db.execSQL(DataFactory.populateUsage());
        db.execSQL(DataFactory.populateLanguage());

        db.setTransactionSuccessful();
        db.endTransaction();
        db.close();
    }
}

The question is, why does it not open a database? Documentation says it has to. I don't accept any dirty workaround as solution like opening the database manually or something. What exactly is wrong on my code? I can't believe it's a bug in Android.

Here is the stacktrace:

05-27 17:25:50.370: I/DefaultSQLiteOpenHelper(719): no database found. Generating new database... 05-27 17:25:50.400: W/dalvikvm(719): threadid=10: thread exiting with uncaught exception (group=0x40015560) 05-27 17:25:50.400: E/AndroidRuntime(719): FATAL EXCEPTION: AsyncTask

1 05-27 17:25:50.400: E/AndroidRuntime(719): java.lang.RuntimeException: An error occured while executing

doInBackground() 05-27 17:25:50.400: E/AndroidRuntime(719): at android.os.AsyncTask$3.done(AsyncTask.java:200) 05-27 17:25:50.400: E/AndroidRuntime(719): at java.util.concurrent.FutureTask$Sync.innerSetException(FutureTask.java:274) 05-27 17:25:50.400: E/AndroidRuntime(719): at java.util.concurrent.FutureTask.setException(FutureTask.java:125) 05-27 17:25:50.400: E/AndroidRuntime(719): at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:308) 05-27 17:25:50.400: E/AndroidRuntime(719): at java.util.concurrent.FutureTask.run(FutureTask.java:138) 05-27 17:25:50.400: E/AndroidRuntime(719): at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1088) 05-27 17:25:50.400: E/AndroidRuntime(719): at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:581) 05-27 17:25:50.400: E/AndroidRuntime(719): at java.lang.Thread.run(Thread.java:1019) 05-27 17:25:50.400: E/AndroidRuntime(719): Caused by: java.lang.IllegalStateException: database not open 05-27 17:25:50.400: E/AndroidRuntime(719): at android.database.sqlite.SQLiteDatabase.endTransaction(SQLiteDatabase.java:555) 05-27 17:25:50.400: E/AndroidRuntime(719): at android.database.sqlite.SQLiteOpenHelper.getWritableDatabase(SQLiteOpenHelper.java:137) 05-27 17:25:50.400: E/AndroidRuntime(719): at com.mydomain.android.base.persistence.PersistenceManager.loadAll(PersistenceManager.java:58) 05-27 17:25:50.400: E/AndroidRuntime(719): at com.mydomain.android.base.main.StartupTask.isFirstStartAfterInstallation(StartupTask.java:107) 05-27 17:25:50.400: E/AndroidRuntime(719): at com.mydomain.android.base.main.StartupTask.doInBackground(StartupTask.java:52) 05-27 17:25:50.400: E/AndroidRuntime(719): at com.mydomain.android.base.main.StartupTask.doInBackground(StartupTask.java:18) 05-27 17:25:50.400: E/AndroidRuntime(719): at android.os.AsyncTask$2.call(AsyncTask.java:185) 05-27 17:25:50.400: E/AndroidRuntime(719): at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:306) 05-27 17:25:50.400: E/AndroidRuntime(719): ... 4 more

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3
  • You might consider posting the stack trace. Commented May 27, 2013 at 17:40
  • @CommonsWare Here it is. Commented May 27, 2013 at 17:44
  • 1
    db.close() in onCreate() is not correct. Commented May 27, 2013 at 17:47

1 Answer 1

Reset to default
5

First, you are closing the database in createAllTables(). Never close the database from onCreate() or onUpgrade() of a SQLiteOpenHelper.

Second, your transaction logic is unnecessary in createAllTables(), as onCreate() is executed in a transaction. This is good, as your transaction logic is improperly implemented, anyway.

To clarify that latter comment, the right way to do transactions is:

try {
    db.beginTransaction();

    // SQL

    db.setTransactionSuccessful();
}
// optional catch block
finally {
    db.endTransaction();
}

You need endTransaction() to be called if there is a SQL exception -- your implementation skips this.

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4 Comments

@CommmonsWare Is it allowed to get a writableDatabase in an AyncTask ? I am tempted to say that it could cause a concurrent exception. Could you light me on this please ?
@CommmonsWare Thanks, what a stupid mistake. :) By the way: Do you mean with improperly implemented that this is the wrong way to do transaction handling (despite on this example where I don't need it)? (I do something similar in my save method).
@user2336315: "Is it allowed to get a writableDatabase in an AyncTask ?" -- not only is it allowed, but it is pretty much mandatory, as getWriteableDatabase() can do significant disk I/O if it has to create or update the database. "I am tempted to say that it could cause a concurrent exception." -- as you can see by looking at the source code, it synchronizes this work.
@CommonsWare Thanks, good to see that I already do it in my save method in this way.

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