Tool or tricks to analyze offline Java heap dumps (.hprof)

Eclipse Memory Analyzer does everything you need.

Can you use jmap -histo ? What sort of report are you looking to extract?

You can use jhat to parse/navigate the memory dump of an .hprof file.

$ jhat heapdump.hprof
Reading from heapdump.hprof...

Started HTTP server on port 7000
Server is ready.

The tool comes with the JDK.