Android Java Project Converts to Kotlin in Android Studio

Question

I want to convert my java project to Kotlin, there are more than 500 java files. How can I convert it into Kotlin easily?

I know that we can convert one by one java file to Kotlin, But there are many files.

Can I convert it at once?

Answer 1

You can definitely try. You just need to select a module or a folder in the Project navigator and select Code --> Convert Java file to Kotlin file:

You, though, need to keep in mind that the conversion is not perfect. For instance, Android Studio will have to guess whether a whole lot of properties are nullable or not. It will not get them all right... you will get a lot of crashes.

My suggestion would be to batch files in sensible chunks, so you can fix those Kotlinized files without getting swamped with errors.

Note: after converting a file to Kotlin you still will need to review it. A lot of things will be kept in Java for the sake of safety, but now that you have Kotlin you can use collection extensions, default constructor parameters, ...