????jmap??????????????????????????-dump??????????jhat???????????????б??
????C:UsersCycle>jhat-help
????Usage:jhat[-stack][-refs][-port][-baseline][-debug][-version][-h|-help]
????-J Pass directly to the runtime system.For
????example??-J-mx512m to use a maximum heap size of 512MB
????-stack false:Turn off tracking object allocation call stack.
????-refs false:Turn off tracking of references to objects
????-port:Set the port for the HTTP server.Defaults to 7000
????-exclude:Specify a file that lists data members that should
????be excluded from the reachableFrom query.
????-baseline:Specify a baseline object dump.Objects in
????both heap dumps with the same ID and same class will
????be marked as not being"new".
????-debug:Set debug level.
????0:No debug output
????1:Debug hprof file parsing
????2:Debug hprof file parsing??no server
????-version Report version number
????-h|-help Print this help and exit
????The file to read
????For a dump file that contains multiple heap dumps??
????you may specify which dump in the file
????by appending"#"to the file name??i.e."foo.hprof#3".
????All boolean options default to"true"
???????jconsole??ó??????????????????????????????????????н???id 3344??
????jmap-dump:format=b??file=heap.bin 3344
?????????????????????????????????????????????????
????jmap-dump:format=b??file=heap.bin 3344
??????????????????
????C:UsersCycleDesktop>jhat heap.bin
????Reading from heap.bin...
????Dump file created Sun Nov 16 19:26:35 IST 2014
????Snapshot read??resolving...
????Resolving 641209 objects...
????Chasing references??expect 128 dots..................
????Eliminating duplicate references.....................
????Snapshot resolved.
????Started HTTP server on port 7000
????Server is ready.
?????????????????http://localhost:7000/??????????????????????

???????磬????????http://localhost:7000/histo/?????????????
????5.Oracle Java Mission Control
???????JVM??????????????????????HotSpot??JRockit VMs??????JRockit Mission Control??????Java SE???????????á?Java Mission Control??JMC????Java Flight Recorder?????????????HotSpot JVM????????????????????????????????????????????????Oracle JDK???????????????Щ?????????????????
????????????????jmc??????????JMC?????