jetifier:tldr:4faf6

The jetifier command is a tool provided by the Android SDK that helps in automatically migrating third-party libraries or packages used in Android projects to use the new AndroidX library structure.

Before AndroidX, the Android Support Library was used to provide additional features on older versions of Android. However, AndroidX was introduced as a replacement for the Support Library starting from Android Jetpack. AndroidX provides updated libraries with improved performance, bug fixes, and new functionalities.

Since many third-party libraries and packages were built using the Android Support Library, they need to be updated to use AndroidX. This is where the jetifier command comes into play.

When the jetifier command is run, it analyzes the dependencies of an Android project and transforms the third-party libraries or packages to use AndroidX equivalents. It basically modifies the code or configuration files of these libraries to ensure they are compatible with AndroidX.

By running jetifier, you can avoid manually updating each library, which can be a time-consuming process. It simplifies the migration process, making it easier to update your Android projects to use the AndroidX library structure.

Here is an example usage of the jetifier command:

npx jetify

This command uses the npx utility (Node Package Runner) to execute the jetify command. npx allows you to run the jetify command without having to install it globally.

When running the jetify command, it typically scans the Android project's dependencies and updates the necessary files to use AndroidX.