How to import third party android library to java file in flutter

Question

I am looking to import a java library to a flutter application. I understand that I will need to call the methods of this java file through a dart bridge or platform channel per https://flutter.io/platform-channels/. However I have yet to be able to make the methods from the library Im trying to import callable or importable. The methods are available when looking at the java file alone in android studio but when viewed with flutter they are unavailable.

Answer 1

With the extra info given, I was able to reproduce the issue.

To edit the native Android app, you have to open it in a new instance of Android Studio:

To add the the libraryx io.particle:cloudsdk:0.5.0, you have to add it to the build.gradle in the app subfolder. You also have to enable Java 1.8 support:

android {
    ...
    compileOptions {
        sourceCompatibility JavaVersion.VERSION_1_8
        targetCompatibility JavaVersion.VERSION_1_8
    }
}

...

dependencies {
    testImplementation 'junit:junit:4.12'
    androidTestImplementation 'com.android.support.test:runner:1.0.2'
    androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.2'

    implementation 'io.particle:cloudsdk:0.5.0'
}

The IDE will only recognize the library when you open the Android project in a separate window. The Flutter app will still compile without a problem.

To get rid of the red error underlining in your Flutter project, you can unload, then reload the Android module (right click on android folder > Load/Unload modules...):