Flutter项目运行报错：无法解析:classpath配置的依赖文件

问题描述 #

刚安装Android Studio并创建Flutter新项目，运行默认代码时出现如下错误：

FAILURE: Build failed with an exception.

* What went wrong:
A problem occurred configuring root project 'android'.
> Could not resolve all files for configuration ':classpath'.
   > Could not find bundletool-1.8.2.jar (com.android.tools.build:bundletool:1.8.2).
     Searched in the following locations:
         https://dl.google.com/dl/android/maven2/com/android/tools/build/bundletool/1.8.2/bundletool-1.8.2.jar
   > Could not find transform-api-2.0.0-deprecated-use-gradle-api.jar (com.android.tools.build:transform-api:2.0.0-deprecated-use-gradle-api).
     Searched in the following locations:
         https://dl.google.com/dl/android/maven2/com/android/tools/build/transform-api/2.0.0-deprecated-use-gradle-api/transform-api-2.0.0-deprecated-use-gradle-api.jar
   > Could not find jetifier-processor-1.0.0-beta09.jar (com.android.tools.build.jetifier:jetifier-processor:1.0.0-beta09).
     Searched in the following locations:
         https://dl.google.com/dl/android/maven2/com/android/tools/build/jetifier/jetifier-processor/1.0.0-beta09/jetifier-processor-1.0.0-beta09.jar
   > Could not find jetifier-core-1.0.0-beta09.jar (com.android.tools.build.jetifier:jetifier-core:1.0.0-beta09).
     Searched in the following locations:
         https://dl.google.com/dl/android/maven2/com/android/tools/build/jetifier/jetifier-core/1.0.0-beta09/jetifier-core-1.0.0-beta09.jar
   > Could not find core-proto-0.0.8-alpha07.jar (com.google.testing.platform:core-proto:0.0.8-alpha07).
     Searched in the following locations:
         https://dl.google.com/dl/android/maven2/com/google/testing/platform/core-proto/0.0.8-alpha07/core-proto-0.0.8-alpha07.jar

* Try:
> Run with --stacktrace option to get the stack trace.
> Run with --info or --debug option to get more log output.
> Run with --scan to get full insights.

* Get more help at https://help.gradle.org

BUILD FAILED in 2s
Exception: Gradle task assembleDebug failed with exit code 1

当前项目根目录下的build.gradle配置如下：

buildscript {
    ext.kotlin_version = '1.8.0'
    repositories {
        google()
        mavenCentral()
    }

    dependencies {
        classpath 'com.android.tools.build:gradle:7.2.2'
        classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
    }
}

allprojects {
    repositories {
        google()
        mavenCentral()
    }
}

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

task clean(type: Delete) {
    delete rootProject.buildDir
}

已确认浏览器可正常访问上述依赖链接，但Gradle无法解析，尝试过常见解决方案无效。

解决步骤 #

1. 检查并调整Gradle代理配置 #

• 打开项目根目录下的gradle.properties文件，查看是否存在代理相关配置（如systemProp.http.proxyHost、systemProp.https.proxyHost）。
• 若未使用代理，删除所有代理配置项；若使用代理，确保代理地址、端口、认证信息正确，且代理允许访问Google Maven仓库。
• 保存文件后，执行flutter clean，再重新运行项目。

2. 替换为国内Maven镜像仓库 #

由于国内访问Google Maven仓库可能存在不稳定情况，可将仓库地址替换为国内镜像：
修改根目录build.gradle中的repositories块：

buildscript {
    ext.kotlin_version = '1.8.0'
    repositories {
        maven { url 'https://maven.aliyun.com/repository/google' }
        maven { url 'https://maven.aliyun.com/repository/public' }
    }

    dependencies {
        classpath 'com.android.tools.build:gradle:7.2.2'
        classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
    }
}

allprojects {
    repositories {
        maven { url 'https://maven.aliyun.com/repository/google' }
        maven { url 'https://maven.aliyun.com/repository/public' }
    }
}

修改后执行flutter clean，再重新构建项目。

3. 清理Gradle本地缓存 #

Gradle缓存损坏可能导致依赖解析失败，清理步骤：

• 关闭Android Studio。
• 删除本地Gradle缓存目录：
  • Windows：C:\Users\<你的用户名>\.gradle\caches
  • Mac/Linux：~/.gradle/caches
• 重新打开项目，执行flutter pub get，再运行项目。

4. 检查Gradle版本与插件版本兼容性 #

Android Gradle插件与Gradle版本需匹配，插件7.2.2对应Gradle版本为7.3.3：

• 打开项目中android/gradle/wrapper/gradle-wrapper.properties文件，修改distributionUrl：

distributionUrl=https\://services.gradle.org/distributions/gradle-7.3.3-all.zip

• 保存后重新运行项目。

5. 手动下载依赖并放入本地仓库 #

若上述方法无效，可手动下载依赖并放置到Gradle本地仓库对应路径：

1. 通过浏览器下载所有提示缺失的jar包。
2. 找到本地Gradle仓库的对应路径，例如bundletool-1.8.2.jar需放入：
   • Windows：C:\Users\<你的用户名>\.gradle\caches\modules-2\files-2.1\com.android.tools.build\bundletool\1.8.2\<随机哈希值>
   • Mac/Linux：~/.gradle/caches/modules-2/files-2.1/com.android.tools.build/bundletool/1.8.2/<随机哈希值>

   哈希值可通过查看Gradle错误日志中的具体路径获取，或创建临时项目触发下载后查看缓存目录结构。

3. 将下载的jar包放入对应路径后，重新运行项目。

内容的提问来源于stack exchange，提问作者AZIN