Build date is incorrect

[lkiesow]

Setting up 16.4 from the RPM packages which were built on the day of the release, I noticed that the date displayed in the admin interface cannot be correct:

The date is off by 20 days:

commit 318ed01e9a546028199399e3788316fb84f4169f (tag: 16.4)
Date:   Thu Aug 15 22:01:20 2024 +0200

Maybe the date is the last start of bundle?

[Arnei]

It does look like that is the case. Then it would be a problem in the backend, where we get the timestamp from "lastmodified": https://github.com/opencast/opencast/blob/6b4dbc80cede37b531c6cbc64ff56c2a3bd9ca28/modules/kernel/src/main/java/org/opencastproject/kernel/bundleinfo/BundleInfoRestEndpoint.java#L82

According to docs:

Returns the time when this bundle was last modified. A bundle is considered to be modified when it is installed, updated or uninstalled.

Are we "installing" bundles when starting Opencast? I don't know how enough about osgi.

[lkiesow]

Looks like we need to change the Java code. We actually store the relevant information in the OSGi bundle metadata.
This should be something like this:

Dictionary<String, Object> headers = bundle.getHeaders();

if (headers != null) {
    Object lastModifiedObj = headers.get("Bnd-LastModified");

    if (lastModifiedObj != null) {
        if (lastModifiedObj instanceof Long) {
            long lastModified = (Long) lastModifiedObj;
            System.out.println("Bnd-LastModified: " + lastModified);