Android Studio Gradle构建失败 求无VPN永久解决方案

问题描述 #

导入多数现有Android项目时频繁遇到Gradle构建失败，因Google对伊朗用户限制相关服务，需借助VPN才能下载依赖库，但VPN连接困难且速度极慢，现咨询：

1. 是否可以手动下载所有依赖库到指定文件夹，并配置到项目中？
2. 是否可像Visual Studio的NuGet一样，更换Android Studio的依赖仓库地址来获取库？

报错信息 #

Could not resolve all artifacts for configuration ':classpath'.
    Could not find gradle-4.2.2.jar (com.android.tools.build:gradle:4.2.2).
     Searched in the following locations:
         https://dl.google.com/dl/android/maven2/com/android/tools/build/gradle/4.2.2/gradle-4.2.2.jar
    Could not find builder-4.2.2.jar (com.android.tools.build:builder:4.2.2).
     Searched in the following locations:
         https://dl.google.com/dl/android/maven2/com/android/tools/build/builder/4.2.2/builder-4.2.2.jar
    Could not find aaptcompiler-4.2.2.jar (com.android.tools.build:aaptcompiler:4.2.2).
     Searched in the following locations:
         https://dl.google.com/dl/android/maven2/com/android/tools/build/aaptcompiler/4.2.2/aaptcompiler-4.2.2.jar
    Could not find bundletool-1.1.0.jar (com.android.tools.build:bundletool:1.1.0).
     Searched in the following locations:
         https://dl.google.com/dl/android/maven2/com/android/tools/build/bundletool/1.1.0/bundletool-1.1.0.jar
    Could not find sdk-common-27.2.2.jar (com.android.tools:sdk-common:27.2.2).
     Searched in the following locations:
         https://dl.google.com/dl/android/maven2/com/android/tools/sdk-common/27.2.2/sdk-common-27.2.2.jar
    Could not find sdklib-27.2.2.jar (com.android.tools:sdklib:27.2.2).
     Searched in the following locations:
         https://dl.google.com/dl/android/maven2/com/android/tools/sdklib/27.2.2/sdklib-27.2.2.jar
    Could not find common-27.2.2.jar (com.android.tools:common:27.2.2).
     Searched in the following locations:
         https://dl.google.com/dl/android/maven2/com/android/tools/common/27.2.2/common-27.2.2.jar
    Could not find protos-27.2.2.jar (com.android.tools.analytics-library:protos:27.2.2).
     Searched in the following locations:
         https://dl.google.com/dl/android/maven2/com/android/tools/analytics-library/protos/27.2.2/protos-27.2.2.jar
    Could not find core-proto-0.0.8-alpha01.jar (com.google.testing.platform:core-proto:0.0.8-alpha01).
     Searched in the following locations:
         https://dl.google.com/dl/android/maven2/com/google/testing/platform/core-proto/0.0.8-alpha01/core-proto-0.0.8-alpha01.jar
    Could not find zipflinger-4.2.2.jar (com.android:zipflinger:4.2.2).
     Searched in the following locations:
         https://dl.google.com/dl/android/maven2/com/android/zipflinger/4.2.2/zipflinger-4.2.2.jar
    Could not find apksig-4.2.2.jar (com.android.tools.build:apksig:4.2.2).
     Searched in the following locations:
         https://dl.google.com/dl/android/maven2/com/android/tools/build/apksig/4.2.2/apksig-4.2.2.jar

项目build.gradle配置 #

// Top-level build file where you can add configuration options common to all sub-projects/modules.
buildscript {
    repositories {
        google()
        mavenCentral()
        jcenter()
    }
    dependencies {
        classpath "com.android.tools.build:gradle:4.2.2"
        // NOTE: Do not place your application dependencies here; they belong
        // in the individual module build.gradle files
    }
}

allprojects {
    repositories {
        google()
        mavenCentral()
        jcenter() // Warning: this repository is going to shut down soon
        maven { url "https://jitpack.io" }
    }
}

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

解决方案 #

1. 手动下载依赖并配置到项目 #

可以手动下载依赖库并配置本地仓库，步骤如下：

• 步骤1：下载依赖包
  根据报错信息里列出的依赖文件路径，手动下载对应的jar包。每个缺失依赖都会标注其查找路径，按照该路径即可获取对应的文件。
• 步骤2：创建本地仓库目录
  在项目根目录下新建一个文件夹（比如命名为local-repo），然后按照Maven标准目录结构存放jar包。例如依赖com.android.tools.build:gradle:4.2.2，需要在local-repo下创建com/android/tools/build/gradle/4.2.2的层级目录，将下载好的jar包放入该目录。如果能找到对应依赖的pom文件，也一并放入；若找不到，可以手动创建一个简单的pom.xml文件，声明依赖的基本groupId、artifactId和version信息。
• 步骤3：配置项目使用本地仓库
  修改项目根目录的build.gradle，在buildscript和allprojects的repositories块中添加本地仓库的引用：

  buildscript {
      repositories {
          maven { url uri('./local-repo') } // 引用本地仓库
          google()
          mavenCentral()
          jcenter()
      }
      // 其他依赖配置不变
  }
  
  allprojects {
      repositories {
          maven { url uri('./local-repo') } // 引用本地仓库
          google()
          mavenCentral()
          jcenter()
          maven { url "https://jitpack.io" }
      }
  }
  

  配置完成后，Gradle会优先从本地仓库查找所需依赖。

2. 更换依赖仓库地址 #

可以替换Google仓库为国内Maven镜像仓库，步骤如下：

• 替换默认仓库为镜像仓库
  修改项目根目录的build.gradle，将google()、mavenCentral()、jcenter()替换为国内主流的Maven镜像仓库地址（可自行搜索国内可靠的Android相关Maven镜像）。示例配置如下：

  buildscript {
      repositories {
          maven { url '国内Google镜像仓库地址' }
          maven { url '国内公共Maven镜像仓库地址' }
          maven { url '国内jcenter镜像仓库地址' }
      }
      dependencies {
          classpath "com.android.tools.build:gradle:4.2.2"
      }
  }
  
  allprojects {
      repositories {
          maven { url '国内Google镜像仓库地址' }
          maven { url '国内公共Maven镜像仓库地址' }
          maven { url '国内jcenter镜像仓库地址' }
          maven { url "https://jitpack.io" }
      }
  }
  

  注意：选择镜像仓库时优先选同步及时、稳定的，若部分依赖仍无法找到，可结合手动下载依赖的方式补充。

内容的提问来源于stack exchange，提问作者Mohamad Hasan Salmaaniyaan