flutter_secure_storage: v5.0.0: error: lambda expressions and method references are not supported in -source 7 (use -source 8 or higher to enable)

I encountered a compiler error when trying to build with flutter_secure_storage v5.0.0. I was able to fix by adding compileOptions to specify Java v8 compatibility to your build.gradle:

Version:

flutter_secure_storage: ^5.0.0

Compile error:

/Users/user/.pub-cache/hosted/pub.dartlang.org/flutter_secure_storage-5.0.0/android/src/main/java/com/it_nomads/fluttersecurestorage/FlutterSecureStoragePlugin.java:250: error: lambda expressions are not supported in -source 7
            handler.post(() -> methodResult.success(result));
                            ^
  (use -source 8 or higher to enable lambda expressions)
/Users/user/.pub-cache/hosted/pub.dartlang.org/flutter_secure_storage-5.0.0/android/src/main/java/com/it_nomads/fluttersecurestorage/FlutterSecureStoragePlugin.java:260: error: method references are not supported in -source 7
            handler.post(methodResult::notImplemented);
                                       ^
  (use -source 8 or higher to enable method references)
2 errors

FAILURE: Build failed with an exception.

Fix:

I was able to get past the compiler errors by specifying the following compileOptions in the android block in:

.../.pub-cache/hosted/pub.dartlang.org/flutter_secure_storage-5.0.0/android/build.gradle

android {
    compileSdkVersion 31

    compileOptions {
        sourceCompatibility JavaVersion.VERSION_1_8
        targetCompatibility JavaVersion.VERSION_1_8
    }

    defaultConfig {
        minSdkVersion 18
        targetSdkVersion 31
        versionCode 6
        versionName "3.3.1"
    }
    lintOptions {
        disable 'InvalidPackage'
    }
}

flutter doctor -v

[✓] Flutter (Channel stable, 2.5.3, on macOS 12.0.1 21A559 darwin-x64, locale en-US)
    • Flutter version 2.5.3 at /Users/user/Documents/Projects/flutter
    • Upstream repository https://github.com/flutter/flutter.git
    • Framework revision 18116933e7 (4 weeks ago), 2021-10-15 10:46:35 -0700
    • Engine revision d3ea636dc5
    • Dart version 2.14.4

[✓] Android toolchain - develop for Android devices (Android SDK version 31.0.0)
    • Android SDK at /Users/user/Library/Android/sdk
    • Platform android-31, build-tools 31.0.0
    • Java binary at: /Applications/Android Studio.app/Contents/jre/Contents/Home/bin/java
    • Java version OpenJDK Runtime Environment (build 11.0.10+0-b96-7281165)
    • All Android licenses accepted.

[✓] Xcode - develop for iOS and macOS
    • Xcode at /Applications/Xcode.app/Contents/Developer
    • Xcode 13.0, Build version 13A233
    • CocoaPods version 1.11.2

[✓] Chrome - develop for the web
    • Chrome at /Applications/Google Chrome.app/Contents/MacOS/Google Chrome

[✓] Android Studio (version 2020.3)
    • Android Studio at /Applications/Android Studio.app/Contents
    • Flutter plugin can be installed from:
      🔨 https://plugins.jetbrains.com/plugin/9212-flutter
    • Dart plugin can be installed from:
      🔨 https://plugins.jetbrains.com/plugin/6351-dart
    • Java version OpenJDK Runtime Environment (build 11.0.10+0-b96-7281165)

[✓] VS Code (version 1.62.2)
    • VS Code at /Applications/Visual Studio Code.app/Contents
    • Flutter extension version 3.28.0

[✓] Connected device (2 available)
    • Nexus 5X (mobile) • 0256574f4c681f87 • android-arm64  • Android 8.1.0 (API 27)
    • Chrome (web)      • chrome           • web-javascript • Google Chrome 95.0.4638.69

• No issues found!