[Sybex 829 - Review Questions Chapter12]

[Federica Sacca']

Hi,
regarding question #3 (Chapter 12 p.713), the related explanation states:
"Option D would be correct if the rest of the command were correct."
Option D is: -m and -p
But, to run a program the command shouldn't be the opposite: -p and -m (making option F the right one)?

Thanks in advance.

[Campbell Ritchie]

Welcome to the Ranch

Don't know, but please tell us who don't have the book/site the full text of the questions.

[Federica Sacca']

Hi,
here attached the screenshot of the question, related answer's options and the review answer.

Thanks.

BR.

[Mikalai Zaikin]

[UPD] the command below is wrong, see update and explanation next posting

Hi Federica, this command would be correct:


java -m zoo.animal.talks/zoo.animal.talks.Peacocks -p modules


where

zoo.animal.talks.Peacocks -- a runnable class' fully qualified class name
zoo.animal.talks -- module name

Syntax:

 -p <module path>
 --module-path <module path>...
                 A ; separated list of directories, each directory
                 is a directory of modules.

      java [options] -m <module>[/<mainclass>] [args...]
      java [options] --module <module>[/<mainclass>] [args...]
          (to execute the main class in a module)

[Federica Sacca']

Hi Mikalai,
thanks for your reply!

So, if I understand correctly, the following command should be the same but in reverse order (it's a run command module example in the book - s.attachment):

java -p mods -m zoo.visitor/zoo.visitor.Tourist

[Mikalai Zaikin]

Hi Federica,

Sorry, my first posting was wrong and you're right.

The -m option must go in the very end, because after the runnable class will go arguments which will be passed into the static main(String[] args)  method, so option -p (module path) may not go after the -m (module), in that case it will be ignored by Java Module System, and passed as array of strings in the main method

This must be the correct command:

java -p modules -m zoo.animal.talks/zoo.animal.talks.Peacocks

[Mikalai Zaikin]

Not sure what is the book on the photos, but seems the explanation is not fully accurate. Besides wrong class name syntax, the order of options is invalid (and it's very important IMHO).

[Federica Sacca']

Hi Mikalai,
thanks again for your feedback.

All the photos in this thread are taken from the book "OCP Study Guide exam 1Z0-829. (This book is very helpful for me   )

[Jeanne Boyarsky]

Mikalai Zaikin wrote:The -m option must go in the very end, because after the runnable class will go arguments which will be passed into the static main(String[] args)  method, so option -p (module path) may not go after the -m (module), in that case it will be ignored by Java Module System, and passed as array of strings in the main method

This must be the correct command:

java -p modules -m zoo.animal.talks/zoo.animal.talks.Peacocks

I didn't know this. Mikalai is correct. I ran it and the behavior matches his statement.

nyjeanne % java -m zoo.animal.feeding/zoo.animal.feeding.Task -p feeding
Error occurred during initialization of boot layer
java.lang.module.FindException: Module zoo.animal.feeding not found
nyjeanne % java -p feeding -m zoo.animal.feeding/zoo.animal.feeding.Task
All fed!

Added to the errata, my notes and my brain

[Jeanne Boyarsky]

This was also wrong in our Java 11 books so added to that errata as well