Flutter集成Firebase遇Gradle构建异常，寻求解决方案

尝试在Flutter应用中集成Firebase，但运行时一直抛出Gradle异常错误。以下是相关文件内容：

android/app/build.gradle 文件内容 #

plugins {
    id "com.android.application"
    id "kotlin-android"
    // The Flutter Gradle Plugin must be applied after the Android and Kotlin Gradle plugins.
    id "dev.flutter.flutter-gradle-plugin"
    id 'com.google.gms.google-services'
}

def localProperties = new Properties()
def localPropertiesFile = rootProject.file("local.properties")
if (localPropertiesFile.exists()) {
    localPropertiesFile.withReader("UTF-8") { reader ->
        localProperties.load(reader)
    }
}

def flutterVersionCode = localProperties.getProperty("flutter.versionCode")
if (flutterVersionCode == null) {
    flutterVersionCode = "1"
}

def flutterVersionName = localProperties.getProperty("flutter.versionName")
if (flutterVersionName == null) {
    flutterVersionName = "1.0"
}

android {
    namespace "com.example.firebase_one"
    compileSdkVersion flutter.compileSdkVersion
    ndkVersion flutter.ndkVersion

    compileOptions {
        sourceCompatibility JavaVersion.VERSION_1_8
        targetCompatibility JavaVersion.VERSION_1_8
        compileSdkVersion 34
    }

    kotlinOptions {
        jvmTarget = '1.8'
    }

    sourceSets {
        main.java.srcDirs += 'src/main/kotlin'
    }

    defaultConfig {
        // TODO: Specify your own unique Application ID (https://developer.android.com/studio/build/application-id.html).
        applicationId = "com.example.firebase_one"
        // You can update the following values to match your application needs.
        // For more information, see: https://docs.flutter.dev/deployment/android#reviewing-the-gradle-build-configuration.
        minSdk = flutter.minSdkVersion
        targetSdk = flutter.targetSdkVersion
        versionCode = flutterVersionCode.toInteger()
        versionName = flutterVersionName
        multidexEnabled = true
    }

    buildTypes {
        release {
            // TODO: Add your own signing config for the release build.
            // Signing with the debug keys for now, so `flutter run --release` works.
            signingConfig = signingConfigs.debug
        }
    }
}

flutter {
    source = "../.."
}

dependencies {
    implementation platform('com.google.firebase:firebase-bom:33.1.0')
}

android/build.gradle 文件内容 #

buildscript {
    ext.kotlin_version = '1.7.10'
    repositories {
        google()
        mavenCentral()
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:7.2.2'
        classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
        classpath 'com.google.gms.google-services:4.4.2'
    }
}
allprojects {
    repositories {
        google()
        mavenCentral()
    }
}

rootProject.buildDir = "../build"
subprojects {
    project.buildDir = "${rootProject.buildDir}/${project.name}"
}
subprojects {
    project.evaluationDependsOn(":app")
}

tasks.register("clean", Delete) {
    delete rootProject.buildDir
}

main.dart 文件内容 #

import 'package:firebase_core/firebase_core.dart';
import 'package:flutter/material.dart';

void main() async{
  WidgetsFlutterBinding.ensureInitialized();
  await Firebase.initializeApp();
  runApp(const MyApp());
}

class MyApp extends StatelessWidget {
  const MyApp({super.key});

  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        
        colorScheme: ColorScheme.fromSeed(seedColor: Colors.deepPurple),
        useMaterial3: true,
      ),
      home: const MyHomePage(title: 'Flutter Demo Home Page'),
    );
  }
}

class MyHomePage extends StatefulWidget {
  const MyHomePage({super.key, required this.title});

  final String title;

  @override
  State<MyHomePage> createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  int _counter = 0;

  void _incrementCounter() {
    setState(() {
    
      _counter++;
    });
  }

  @override
  Widget build(BuildContext context) {
   
    //
    
    return Scaffold(
      appBar: AppBar(
        
        backgroundColor: Theme.of(context).colorScheme.inversePrimary,
        
        title: Text(widget.title),
      ),
      body: Center(
        
        child: Column(
          
          mainAxisAlignment: MainAxisAlignment.center,
          children: <Widget>[
            const Text(
              'You have pushed the button this many times:',
            ),
            Text(
              '$_counter',
              style: Theme.of(context).textTheme.headlineMedium,
            ),
          ],
        ),
      ),
      floatingActionButton: FloatingActionButton(
        onPressed: _incrementCounter,
        tooltip: 'Increment',
        child: const Icon(Icons.add),
      ), // This trailing comma makes auto-formatting nicer for build methods.
    );
  }
}

可能的解决方案 #

• 修复compileSdkVersion重复定义冲突
  在android/app/build.gradle的android块中，compileSdkVersion被重复定义了两次（外层和compileOptions内），删除compileOptions中的重复行：

  compileOptions {
      sourceCompatibility JavaVersion.VERSION_1_8
      targetCompatibility JavaVersion.VERSION_1_8
      // 移除该行：compileSdkVersion 34
  }
  

• 确认Firebase配置文件存在
  检查android/app目录下是否存在从Firebase控制台下载的google-services.json文件，缺少该文件会导致初始化失败。

• 更新Gradle相关依赖版本
  当前使用的Gradle插件和Google Services插件版本可能存在兼容问题，更新为匹配版本：
  修改android/build.gradle中的依赖：

  dependencies {
      classpath 'com.android.tools.build:gradle:7.4.2'
      classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
      classpath 'com.google.gms.google-services:4.4.10'
  }
  

  同时更新gradle/wrapper/gradle-wrapper.properties中的Gradle版本，确保与插件兼容：

  distributionUrl=https\://services.gradle.org/distributions/gradle-7.5-all.zip
  

• 添加Firebase Core显式依赖
  虽然引入了Firebase BOM，仍需显式添加Core依赖保证初始化正常，在android/app/build.gradle的dependencies块中补充：

  implementation platform('com.google.firebase:firebase-bom:33.1.0')
  implementation 'com.google.firebase:firebase-core'
  

• 清理缓存并重新构建
  执行以下命令清理项目缓存后重新构建：

  flutter clean
  flutter pub get
  cd android && ./gradlew clean build
  cd .. && flutter run
  

内容的提问来源于stack exchange，提问作者Starc