/** * 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 {@link #onCreate}, {@link #onUpgrade} and/or {@link * #onOpen} will be called. * * <p>Once opened successfully, the database is cached, so you can call this method every time you * need to write to the database. (Make sure to call {@link #close} when you no longer need the * database.) Errors such as bad permissions or a full disk may cause this method to fail, but * future attempts may succeed if the problem is fixed. * * <p class="caution">Database upgrade may take a long time, you should not call this method from * the application main thread, including from {@link android.content.ContentProvider#onCreate * ContentProvider.onCreate()}. * * @throws SQLiteException if the database cannot be opened for writing * @return a read/write database object valid until {@link #close} is called */ public synchronized SQLiteDatabase getWritableDatabase() { if (mDatabase != null) { if (!mDatabase.isOpen()) { // darn! the user closed the database by calling mDatabase.close() mDatabase = null; } else if (!mDatabase.isReadOnly()) { return mDatabase; // The database is already open for business } } if (mIsInitializing) { throw new IllegalStateException("getWritableDatabase called recursively"); } // If we have a read-only database open, someone could be using it // (though they shouldn't), which would cause a lock to be held on // the file, and our attempts to open the database read-write would // fail waiting for the file lock. To prevent that, we acquire the // lock on the read-only database, which shuts out other users. boolean success = false; SQLiteDatabase db = null; if (mDatabase != null) mDatabase.lock(); try { mIsInitializing = true; if (mName == null) { db = SQLiteDatabase.create(null); } else { db = SQLiteDatabase.openDatabase( mName, mPasswd, mFactory, 0); // mContext.openOrCreateDatabase(mName, 0, mFactory, mErrorHandler); } int version = db.getVersion(); if (version != mNewVersion) { db.beginTransaction(); try { if (version == 0) { onCreate(db); } else { if (version > mNewVersion) { onDowngrade(db, version, mNewVersion); } else { onUpgrade(db, version, mNewVersion); } } db.setVersion(mNewVersion); db.setTransactionSuccessful(); } finally { db.endTransaction(); } } onOpen(db); success = true; return db; } finally { mIsInitializing = false; if (success) { if (mDatabase != null) { try { mDatabase.close(); } catch (Exception e) { } mDatabase.unlock(); } mDatabase = db; } else { if (mDatabase != null) mDatabase.unlock(); if (db != null) db.close(); } } }