Android SDK cannot be updated

1. Under SDK Manager tools->options Open SDK Manager settings, select "Force https://... sources to be fetched using http://...", Enforces the use of the HTTP protocol.
2, modify the host file, add the following two lines

#google_android更新
203.208.46.146 dl.google.com
203.208.46.146 dl-ssl.google.com

Other:
Windows modifies the host method
WINDOWS open C:\WINDOWS\system32\drivers\etc\hosts file directly modified

Mac Change Host method
1. Open terminal (terminal), input: sudo vi/etc/hosts
2. Enter the system password
3. Input I enter edit mode
4. After the edit is complete, press ESC and enter: WQ

Android SDK cannot be updated