Saving Data

Dependencies and prerequisites

  • Android 1.6 (API Level 4) or higher
  • Familiarity with Map key-value collections
  • Familiarity with the Java file I/O API
  • Familiarity with SQL databases

You should also read

Most Android apps need to save data, even if only to save information about the app state during onPause() so the user's progress is not lost. Most non-trivial apps also need to save user settings, and some apps must manage large amounts of information in files and databases. This class introduces you to the principal data storage options in Android, including:

  • Saving key-value pairs of simple data types in a shared preferences file
  • Saving arbitrary files in Android's file system
  • Using databases managed by SQLite

Lessons

Saving Key-Value Sets
Learn to use a shared preferences file for storing small amounts of information in key-value pairs.
Saving Files
Learn to save a basic file, such as to store long sequences of data that are generally read in order.
Saving Data in SQL Databases
Learn to use a SQLite database to read and write structured data.