How to update the Java keystore with a website certificate (Let’s Encrypt)

As a brief note to self, I use these Java keytool commands to add/update the SSL certificate for accessing a website named

- run this command to delete the alpha entry:
  sudo keytool -delete -alias "" -keystore /usr/lib/jvm/jdk-8-oracle-arm32-vfp-hflt/jre/lib/security/cacerts

- run this command to add (re-add) the alpha entry:
  sudo sh

- also, to list entries:
  keytool -list -v -keystore /usr/lib/jvm/jdk-8-oracle-arm32-vfp-hflt/jre/lib/security/cacerts

I also use the instructions on this web page to download the certificate file for their website (using Firefox).

As I’ve noted elsewhere, the default password for the Oracle Java keystore is changeit.