HttpClient  is not supported any

6.0 之后官方移除了内置的HttpClient支持 解决办法如下

Android 6.0 release removes support for the Apache HTTP client. If your app is using this client and targets Android 2.3 (API level 9) or higher, use theHttpURLConnection
class instead. This API is more efficient because it reduces network use through transparent compression and response caching, and minimizes power consumption. To continue using the Apache HTTP APIs, you must first declare the following compile-time dependency in yourbuild.gradle
file:

android {  
  useLibrary 'org.apache.http.legacy'
}

官方地址: https://developer.android.com/about/versions/marshmallow/android-6.0-changes.html#boringSSL