Can I code in Java in flutter?

Dart is currently actively used with Flutter for developing the frontend of cross-platform mobile apps. Dart can be also used for web development, but there is no mention of Dart being used for backend development .

Introduction. Dart is the programming language for Flutter, Google’s UI toolkit for building beautiful, natively compiled mobile, web, and desktop apps from a single codebase . This codelab introduces you to Dart with a focus on features that Java developers might not expect.3 Kas 2021

Flutter uses a flexible system that allows you to call platform-specific APIs in a language that works directly with those APIs: Kotlin or Java on Android .