Your stop for HPE End-of-Sale Products information can be found here (notice the dual link to End-of-Sale pages with both recent and legacy announcements and the Product End-of-Life Infromation page)
Your stop for HPE Networking Warranty information can be found here.
Looking at the HPE Networking Warranty Coverage Quick Reference here, your JG237A is covered by Limited Lifetime Warranty and there is a note about: "Limited lifetime (for products purchased after December 1, 2014 the warranty extends only for as long as the original bona fide end user continues to own or use the product)".
HPE Networking Warranty FAQs can be read here.
With regard to documentation...check support.hpe.com or google for My Networking Lookup Tool (for Firmware too).