JEP 408 https://openjdk.org/jeps/408, in Java 18, introduced the Simple Web Server - a minimal web server capable of serving static files over HTTP.

HTTP RFC 9110 specifies "Range Requests" which is an optional feature of HTTP. Range requests allow for clients to request a subset of the target resource's content.

In the context of JDK's Simple Web Server, supporting Range requests would mean serving a subset of the target static file's contents. Specifically, the implementation of sun.net.httpserver.simpleserver.FileServerHandler in the jdk.httpserver module would have to be enhanced to implement the HTTP Range requests specification.

A recent discussion on net-dev mailing list has asked for this enhancement along with an example use case of such feature https://mail.openjdk.org/pipermail/net-dev/2025-April/026364.html