Source not available doesn’t mean hide, it’s because java source file(java.frag) doesn’t exist. Hide means you can’t see them, for example the services in WmRoot package are hidden by default(controlled by extended settings).
If you want your java service Source not available, just don’t select any *.java and java.frag when you export.
If you want to hide your services, whatever java service or flow service, you can set the read ACL to a suitable one(for example Administrator ACL), then users not belong to this ACL(for example user just belongs to Developers ACL) can’t see them.
#webMethods#Integration-Server-and-ESB