android开发时 android studio gradle：download http：//jcenter卡住

这是因为gradle sync时部分网址被墙的原因，一些资源无法下载，推荐使用阿里源去解决这样的问题。

在当前用户主目录的.gradle目录下，新建init.gradle文件，内容如下

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

        all { ArtifactRepository repo ->
            if (repo instanceof MavenArtifactRepository) {
                def url = repo.url.toString()

                if (url.startsWith('https://repo.maven.apache.org/maven2/') || url.startsWith('https://repo.maven.org/maven2') 
                    || url.startsWith('https://repo1.maven.org/maven2') || url.startsWith('https://jcenter.bintray.com/')
                    || url.startsWith('https://maven.google.com/') || url.startsWith('https://dl.google.com/dl/android/maven2/')) {
                    //project.logger.lifecycle "Repository ${repo.url} replaced by $REPOSITORY_URL."
                    remove repo
                }
            }
        }
    }

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

            all { ArtifactRepository repo ->
                if (repo instanceof MavenArtifactRepository) {
                    def url = repo.url.toString()
                    if (url.startsWith('https://repo1.maven.org/maven2') || url.startsWith('https://jcenter.bintray.com/')
                         || url.startsWith('https://dl.google.com/dl/android/maven2/')) {
                        //project.logger.lifecycle "Repository ${repo.url} replaced by $REPOSITORY_URL."
                        remove repo
                    }
                }
            }
        }
    }

}