Failed to resolve: com.android.support:appcompat-v7:28.+

buildscript {
repositories {
// mavenCentral()
// jcenter()
// google()
maven { url 'https://maven.aliyun.com/repository/gradle-plugin' }
maven { url 'https://maven.aliyun.com/repository/google' }
maven { url 'http://maven.aliyun.com/nexus/content/groups/public/' }
maven { url 'https://maven.aliyun.com/repository/jcenter'}
}
dependencies {
classpath 'com.android.tools.build:gradle:3.0.1'
}
}

allprojects {
repositories {
// mavenCentral()
// jcenter()
// google()
maven { url 'https://maven.aliyun.com/repository/gradle-plugin' }
maven { url 'https://maven.aliyun.com/repository/google' }
maven { url 'http://maven.aliyun.com/nexus/content/groups/public/' }
maven { url 'https://maven.aliyun.com/repository/jcenter'}

}

}