Convert Android Project into flutter project

Converting a full Android Java project into a Flutter project (or embedding Flutter into a Java app) is possible — but there’s no automatic “convert” button. It involves a mostly manual rewrite / integration. Here’s a clear, correct “how to” and what you need to do.

Two Main Paths: Full Rewrite vs. Hybrid (Add-to-App)

When you move from a Java Android app to Flutter, you have two broad strategies:

• Full rewrite — rebuild the entire app in Flutter/Dart.

• Hybrid approach (Add to App / module) — embed Flutter as a module in your existing Android project, and gradually migrate screens/features. Flutter Docs+2Medium+2

Which strategy you choose depends on factors like complexity, how much of the original code you want to reuse, how stable the existing app is, and how much time you have.

Step-by-Step: Embed Flutter Module into Existing Java Android Project

If you want to keep the existing Java code and gradually migrate to Flutter, here is the common method (“Add-to-App / hybrid”).

1. Create a Flutter module
   In terminal at your project root (or wherever you want), run:

   flutter create -t module flutter_module
   

   This creates a directory flutter_module/ which contains a Flutter project. Medium+1

2. Include the Flutter module in your Android project

   • In your Android app’s settings.gradle, add the Flutter module. Example:

     setBinding(new Binding([gradle: this]))
     evaluate(new File(
       settingsDir, 
       '../flutter_module/.android/include_flutter.groovy'
     ))
     

   • In your app-level build.gradle, add dependency on Flutter module, like:

     dependencies {
         implementation project(':flutter')
     }
     

     (Or use .aar output if using AAR approach.) Medium+1

3. Decide which screens / features to migrate first
   You might want to start with simpler screens: login, profile, settings — things that are UI-heavy but not deeply tied to native code or complex platform-specific APIs. That reduces risk. flutternest.com+1

4. Handle communication between Java (native) and Flutter (Dart)
   Use Platform Channels (method channels / message channels) to let Dart code call Java code, or vice versa, when needed (e.g. for native-only features, device APIs, etc.). flutter-website-staging.firebaseapp.com+1

5. Migrate resources and dependencies

   • Copy over resources: images, strings, layouts (if needed), icons, manifest entries.

   • For native dependencies (Java libraries), you may still need them — either keep in native part, or find/rewrite for Flutter (using Flutter plugins). Medium+1

6. Test thoroughly — hybrid apps can introduce complexity (navigation between native and Flutter screens, state continuity, platform-channel bugs).

This hybrid approach lets you incrementally migrate instead of rewriting everything at once. Many teams follow this when converting production-grade native apps to Flutter. agilevision.io+1

If You Want a Full Rewrite in Flutter

If you decide to rewrite completely:

• Create a new Flutter project:
  flutter create my_new_app Flutter Docs+1

• Re-implement screens in Dart + Flutter widgets, and backend logic / API code in Dart.

• Reuse design resources (images, icons) from old project, but layouts must be rebuilt in Flutter.

• Maintain same application semantics (APIs, data models), or adjust as needed.

This gives you a cross-platform app (Android + iOS + maybe web), single codebase, and easier future maintenance. Many switch because of these long-term benefits. calgaryappdeveloper.ca+1

What Flutter Can’t Do Automatically

• There is no automated converter that takes Java Android code and produces equivalent Flutter code (UI or business logic). All UI has to be rewritten manually.

• Native-only features (device sensors, platform-specific libraries) often require custom Flutter plugins or platform-channel bridging.

 My Recommendation (Given Your Background)

Given that you have an Android-Java project, but likely want cross-platform support and easier maintenance:

• Start with hybrid migration — embed a Flutter module as described. Convert non-critical screens first (settings, login, profile).

• Build familiarity with Flutter + Dart while keeping your native code working.

• Gradually migrate more screens/modules until you can replace the native app entirely — or keep hybrid if some native parts are easier in Java.