Question

I need to recognize first launch of my application or activity.

At this time I need to get some information from server create local database and save info to it. What is the best way to do this?

1. Create any preferences for example FirstLaunch and set true \ false to it.
2. Check whether my database exists or not.
3. Something else?

PS. All server calls must be into one transaction. Ormlite supports transactions?
Thanks.

Answer 1

For the “create database at first run”-purpose, you should use an SQLiteOpenHelper, which offers you the onCreate()-method that is called when:

[…] the database is created for the first time.

The Database-file itself will be created for you (you don’t have to do this manually). In this method, you can then perform actions like populating your database with standard entry’s.

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If you want to populate the database with informations you get from your server, there might be a problem when there is no Internet-connection available.

In this case, I would check if there is a connection available:

• If there is, get your informations.
• If not, show a Toast or some other notification to inform the user.

To determine if your Database has be populated with the standard entry’s, you can use the database-version which is also provided by the SQLiteDatabase-class:

• When you first create your Database-object, you call
  SQLiteOpenHelpers constructor and pass it 0 as the Database
  version.
• If you successfully populated your database, you use
  setVersion()-method to alter it to 1.
• Later in the onOpen()-method, which is called when the
  database is opened, you can check if the database was populated by
  using the getVersion()-method.
  • If it is populated, call the super-method to open it.
  • If not, try populating it.

Further more, the getReadableDatabase() / getWritableDatabase()-methods should be called off the main-thread anyways because:

Database upgrade may take a long time, you should not call this method
from the application main thread, including from
ContentProvider.onCreate().

So getting the informations from the Internet can take place in the onCreate() and in the onOpen()-method (if it wasn’t successful at the first try). You can (for example) use a Service to do this.