"Unable to find valid certification path to requested target"
If you are getting this message, you probably are behind a Proxy on your company, which probably is signing all request certificates with your company root CA certificate, this certificate is trusted only inside your company, so Android Studio cannot validate any certificate signed with your company certificate as valid, so, you need to tell Android Studio to trust your company certificate, you do that by adding your company certificate to Android Studio truststore.
(I'm doing this on macOS, but should be similar on Linux or Windows)
On the popup window, to save the root certificate as a file, make sure to select the top level of the certificates chain (the root cert) and drag the certificate image to a folder/directory on your disk drive. It should be saved as a file as, for example: my-root-ca-cert.cer, or my-root-ca-cert.pem
On Android Studio open Preferences -> Tools -> Server Certificates
,
on the box Accepted certificates
click the plus icon (+
), search the certificate you saved previously and click Apply
and OK
In Android Studio open File -> Project Structure -> SDK Location -> JDK Location
Copy the path of JDK Location, and open the Terminal, and change your directory to that path, for example, execute:
cd /Applications/Android\ Studio.app/Contents/jre/jdk/Contents/Home/
(don't forget to scape the whitespace, "\ ")
Now, to import the certificate to the truststore, execute:
./bin/keytool -importcert -file /path/to/your/certificate/my-root-ca-cert.cer -keystore ./jre/lib/security/cacerts -storepass changeit -noprompt
File -> Invalidate Caches / Restart
Done, you should be able to build your project now.