how to access an in memory variable of a java program, while it is running?

Question

i am running a java crawler program in eclipse. I have not enabled a debugger.

I am printing some variables after the crawling is complete. but the crawler takes a lot of time to complete so i don't know when these variables will be printed.

i want to access these variables while the crawler is running and i dont want to stop it because it is already running for a while. How do i access these variables? thanks

Answer 1

the program has been running for 1.5 day. i dont want to stop now and use debugger or println

If you cannot change the code of a running process (which is an important detail for a developer to forget to mention) your only option is to trigger a heap dump using VisualVM or the like. This will give you the entire JVM but in it will be your HashTable.