1. 使用阿里云国内镜像
   对单个项目生效，在项目中的build.gradle修改内容：

buildscript {
    repositories {
        maven { url 'http://maven.aliyun.com/nexus/content/groups/public/' }
                maven{ url 'http://maven.aliyun.com/nexus/content/repositories/jcenter'}
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:2.2.3'
 
        // 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/' }
        maven{ url 'http://maven.aliyun.com/nexus/content/repositories/jcenter'}
    }
}

对所有项目生效，在USER_HOME/.gradle/下创建init.gradle文件：

allprojects{
    repositories {
        def ALIYUN_REPOSITORY_URL = 'http://maven.aliyun.com/nexus/content/groups/public'
        def ALIYUN_JCENTER_URL = 'http://maven.aliyun.com/nexus/content/repositories/jcenter'
        def GRADLE_LOCAL_RELEASE_URL = 'https://repo.gradle.org/gradle/libs-releases-local'
        def ALIYUN_SPRING_RELEASE_URL = 'https://maven.aliyun.com/repository/spring-plugin'
        
        all { ArtifactRepository repo ->
            if(repo instanceof MavenArtifactRepository){
                def url = repo.url.toString()
                if (url.startsWith('https://repo1.maven.org/maven2')) {
                    project.logger.lifecycle "Repository ${repo.url} replaced by $ALIYUN_REPOSITORY_URL."
                    remove repo
                }
                if (url.startsWith('https://jcenter.bintray.com/')) {
                    project.logger.lifecycle "Repository ${repo.url} replaced by $ALIYUN_JCENTER_URL."
                    remove repo
                }
                if (url.startsWith('http://repo.spring.io/plugins-release')) {
                    project.logger.lifecycle "Repository ${repo.url} replaced by $ALIYUN_SPRING_RELEASE_URL."
                    remove repo
                }
                
            }
        }
        maven {
            url ALIYUN_REPOSITORY_URL     
        }
        
        maven {            
            url ALIYUN_JCENTER_URL          
        }
        maven {            
            url ALIYUN_SPRING_RELEASE_URL
        }
        maven {
            url GRADLE_LOCAL_RELEASE_URL
        }
        
    }
    
 
}