As配置阿里镜像，实测可用，真香~

在开发中，涉及到很多资源下载。所以一般都需要外面的资源

有时候又下载不了。所以需要配置一下镜像地址

maven {
            url "http://maven.aliyun.com/nexus/content/groups/public/"
        }

以下是我project下的build.gradle的配置

// Top-level build file where you can add configuration options common to all sub-projects/modules.
apply from: "dependencies.gradle"
buildscript {
    repositories {
        maven {
            url "http://maven.aliyun.com/nexus/content/groups/public/"
        }
        google()
        jcenter()
        
    }
    dependencies {
        classpath com.android.tools.build:gradle:3.5.2
        classpath com.jakewharton:butterknife-gradle-plugin:10.2.1
        // NOTE: Do not place your application dependencies here; they belong
        // in the individual module build.gradle files
    }
}

allprojects {
    repositories {
        maven {
            url "http://maven.aliyun.com/nexus/content/groups/public/"
        }
        google()
        jcenter()
        
    }
}

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