Chapter 17. Data Persistence and Sharing
In this chapter, we will look at a couple of different ways to save data to an Android device's permanent storage. Also, for the first time, we will add a second Activity to our app. It often makes sense when implementing a separate "screen," such as a settings screen, in our app to do so in a new Activity. We could go to the trouble of hiding the original UI and then showing the new UI, but this would quickly lead to confusing and error-prone code. So, we will see how to add an Activity and navigate the user between them.
In summary, in this chapter, we will do the following:
- Learn about Android Intents to switch
Activityand pass data - Create a simple (very simple) settings screen in a new
Activity - Persist the settings screen data using the
SharedPreferencesclass - Learn about JavaScript Object Notation (JSON) for serialization
- Explore Java's
try-catch-finally - Implement saving data in our Note to Self app
