Java官方文档

https://www.oracle.com/java/technologies/

https://www.oracle.com/java/technologies/downloads/archive/

https://www.oracle.com/java/technologies/javase/jdk17-archive-downloads.html

https://docs.oracle.com/en/java/index.html

https://docs.oracle.com/en/java/javase/index.html

https://docs.oracle.com/en/java/javase/17/

https://docs.oracle.com/en/java/javase/17/docs/specs/man/index.html

https://docs.oracle.com/javase/specs/index.html

free -m
free -g
top
top -Hp <pid>
jmap -help
jmap -heap <pid>
jmap -histo:live <pid> | more
jmap -dump:live,format=b,file=heap.bin <pid>
jstat -options
jstat -gcutil <pid> 1000