flutter报错HTTP Host Availability (the doctor check crashed)的解决办法

[☠] HTTP Host Availability (the doctor check crashed)
    X Due to an error, the doctor check did not complete. If the error message below is not helpful, please let us know about this issue at https://github.com/flutter/flutter/issues.
    X HandshakeException: Connection terminated during handshake

 解决办法：
1、找到flutter sdk的文件目录，打开下面路径文件
flutter\packages\flutter_tools\lib\src\http_host_validator.dart
2、找到以下链接替换

https://maven.google.com/ 改为 https://dl.google.com/dl/android/maven2/

kPubDevHttpHost 改为https://pub.flutter-io.cn/

kgCloudHttpHost 改为https://storage.flutter-io.cn/

3、进入到flutter\bin目录，删除cache目录下的flutter_tools.snapshot 文件
4、新开一个cmd，在cmd命令窗口重新运行flutter doctor,问题解决。