Flutter集成Firebase后Gradle报错：找不到com.google.gms.google-services插件

问题描述 #

按照官方文档在Flutter项目中集成Firebase Auth，修改Android Gradle文件后构建失败：

• 异常位置：构建文件E:\Projects\Android Projects\instagram_clone\android\app\build.gradle第27行
• 错误提示：评估项目':app'时出现问题，Plugin with id 'com.google.gms.google-services' not found.

已尝试添加com.google.gms.google-services插件，但问题仍存在，以下是当前根级和模块级Gradle文件内容：

根级（项目级）Gradle文件（/build.gradle） #

buildscript {
    ext.kotlin_version = '1.7.10'
    repositories {
        google()
        mavenCentral()
    }

    dependencies {
        classpath 'com.android.tools.build:gradle:7.3.0'
        classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
        classpath: 'com.google.gms.google-services:4.3.15'
    }
}

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
}

模块（app级）Gradle文件（//build.gradle） #

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

def flutterRoot = localProperties.getProperty('flutter.sdk')
if (flutterRoot == null) {
    throw new GradleException("Flutter SDK not found. Define location with flutter.sdk in the local.properties file.")
}

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

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

apply plugin: 'com.android.application'
apply plugin: 'kotlin-android'
apply from: "$flutterRoot/packages/flutter_tools/gradle/flutter.gradle"
apply plugin: 'com.google.gms.google-services'

android {
    namespace "com.clones.instagram_clone"
    compileSdkVersion flutter.compileSdkVersion
    ndkVersion flutter.ndkVersion

    compileOptions {
        sourceCompatibility JavaVersion.VERSION_1_8
        targetCompatibility JavaVersion.VERSION_1_8
    }

    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.clones.instagram_clone"
        // 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.
        minSdkVersion localProperties.getProperty('flutter.minSdkVersion').toInteger()
        targetSdkVersion 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 "org.jetbrains.kotlin:kotlin-stdlib-jdk7:$kotlin_version"
    implementation "com.android.support:multidex:2.0.1"
    implementation "com.google.firebase:firebase-bom:32.2.0"
}

问题原因 #

根级Gradle文件中添加com.google.gms.google-services插件时存在语法错误：

classpath: 'com.google.gms.google-services:4.3.15'

这里错误使用了冒号:，正确的Gradle依赖声明应该使用空格，而非冒号。

修复方案 #

修改根级Gradle文件中的依赖声明，将冒号改为空格：

classpath 'com.google.gms.google-services:4.3.15'

修改后的完整根级Gradle文件：

buildscript {
    ext.kotlin_version = '1.7.10'
    repositories {
        google()
        mavenCentral()
    }

    dependencies {
        classpath 'com.android.tools.build:gradle:7.3.0'
        classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
        classpath 'com.google.gms.google-services:4.3.15'
    }
}

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
}

额外建议 #

1. 确保根级Gradle的repositories中包含google()，这样Gradle才能从Google Maven仓库拉取插件。
2. 执行flutter clean后重新构建项目，清除缓存避免残留问题。

内容的提问来源于stack exchange，提问作者user21934236