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Tag: jvm

How to inspect jvm module contents from the command line?

I would like to inspect the contents of a resource file of a java module of my locally installed jvm from the command line. Based on a question about mime type support in a jvm I would like to see the contents of /sun/net/www/ in module java.base of my locally installed jvm. However when scrolling through the files installed for

What is the use of the “dup2_x2” instruction in JVM bytecode?

Java has a dup2_x2 instruction which, according to the documentation, has the following behavior: Duplicate the top one or two values on the operand stack and insert the duplicated values, in the original order, into the operand stack. Does javac produce bytecode with this instruction? What are its potential use cases? Answer For example, the following code compiles to See,

Print a value of an extended class object from mother class object

I’ve declared a table that has the mother class type and i’ve filled it with many objects that have the extended classe type, everything looks fine and the table is successfully filled, the problem is when i’m trying to access to the table values i cannot ( in the exemple i’m trying to get the salaire attribut ) MOTHER CLASS

How does java guarateee reserved memory

Checking for memory usage by stack using this command: I can see that reserved memory is different from committed. Reserved is about 1MB (default for stack). Committed in fact is physical reserved. I read that java save memory for stack while is not totally used. Running command like top I can see just committed usage. What does java/SO do in