/**
* Create and/or open a database that will be used for reading and writing. The first time this is
* called, the database will be extracted and copied from the application's assets folder.
*
* <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
*/
@Override
public synchronized SQLiteDatabase getWritableDatabase() {
if (mDatabase != null && mDatabase.isOpen() && !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 = mContext.openOrCreateDatabase(mName, 0, mFactory);
// }
db = createOrOpenDatabase(false);
int version = db.getVersion();
// do force upgrade
if (version != 0 && version < mForcedUpgradeVersion) {
db = createOrOpenDatabase(true);
db.setVersion(mNewVersion);
version = db.getVersion();
}
if (version != mNewVersion) {
db.beginTransaction();
try {
if (version == 0) {
onCreate(db);
} else {
if (version > mNewVersion) {
Log.w(
TAG,
"Can't downgrade read-only database from version "
+ version
+ " to "
+ mNewVersion
+ ": "
+ db.getPath());
}
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();
}
}
}
