Jetty-12 can't retrieve some resources (lastModified wrong type)

[SergYarovoye]

Jetty version(s)
12.0.0+

Jetty Environment
ee8

Java version/vendor
openjdk version "17.0.4.1" 2022-08-12 LTS
OpenJDK Runtime Environment (build 17.0.4.1+1-LTS)
OpenJDK 64-Bit Server VM (build 17.0.4.1+1-LTS, mixed mode, sharing)

OS type/version
KUbuntu 22.04
Linux
5.15.0-83-generic
x86_64

Description
My app started, but some resources didn't load in browser.
Mostly PNG images.
Debug showed a problem:
in org.eclipse.jetty.http.content.ResourceHttpContent#getLastModified we created HttpField with value as string representation of lastModified date (example: "Tue, 19 Sep 2023 08:59:00 GMT"),
but later, in org.eclipse.jetty.ee8.nested.Response.putHeaders we try to get this value as Long.
Exception as a result:

09-19;16:02:51.987 WARN [ qtp244185498-30][ o.e.j.e.n.ResourceService][]: Failed to serve resource: /images/icons/32/id_card.png
java.lang.NumberFormatException: For input string: "Tue, 19 Sep 2023 08:59:00 GMT"
at java.base/java.lang.NumberFormatException.forInputString(NumberFormatException.java:67)
at java.base/java.lang.Long.parseLong(Long.java:711)
at java.base/java.lang.Long.parseLong(Long.java:836)
at org.eclipse.jetty.http.HttpField.getLongValue(HttpField.java:355)
at org.eclipse.jetty.ee8.nested.Response.putHeaders(Response.java:1198)
at org.eclipse.jetty.ee8.nested.ResourceService.putHeaders(ResourceService.java:717)
at org.eclipse.jetty.ee8.nested.ResourceService.sendData(ResourceService.java:564)
at org.eclipse.jetty.ee8.nested.ResourceService.doGet(ResourceService.java:279)
at org.eclipse.jetty.ee8.servlet.DefaultServlet.doGet(DefaultServlet.java:432)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:503)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:590)

But other images and other resources successfully loaded.

How to reproduce?
Just run jetty-12 with ee8 env, try to load image from your app class path.

How to fix
Just change org.eclipse.jetty.http.content.ResourceHttpContent#getLastModified:

public HttpField getLastModified()
{
    Instant lm = _resource.lastModified();
    return new HttpField.LongValueHttpField(HttpHeader.LAST_MODIFIED, DateGenerator.formatDate(lm), lm.toEpochMilli());
}

[janbartel]

Duplicate of #10463.

[janbartel]

Closing as duplicate