Command Line Overview and Multiple Modules

Executable	Java options	Example(s)	Explanation
java	--list-modules	java --list-modules java -p MyFirstModule.jar --list-modules	List visible modules. If you do not specify a module path, you'll get a listing of the modular Java Development Kit. If you specify directories in the module path, you'll include visible modules in those directories (either exploded directories or jar files).
java	-p --module-path	java --module-path . -m MyFirstModule java -p . -m MyFirstModule	You need to specify the module path when executing a module jar.
java	-m --module	java -p . -m MyFirstModule java -p . --module MyFirstModule	You need to specify the module name when executing a module jar.

Become familiar with these commands.

-p and 
--module path

Are the same thing. You need to specify the module path when you execute a module jar.

-m or 
--module

You need to specify the module name when you execute a module jar.

dry-run

Executable	Java options	Example(s)	Explanation
java	--dry-run	java --dry-run -p . --module MyFirstModule	The --dry-run option loads the main class but does not run it, used for testing module dependencies are satisfied. A successful result is no output.
java	-d --describe-module	java --module-path . --describe-module MyFirstModule java -p . -d MyFirstModule	The --describe-module option gives you summary information about a module including its path, its dependencies, and its packages and resources.

The dry run option loads the main class but does not run it, used for testing module dependencies are satisfied a successful result is no output

--describe-module

The describe module option gives you summary information about a module including its path, its dependencies, and its packages and resources.

Javac command

Executable	Java options	Example(s)	Explanation
javac	--module -m	javac -d out\production --module-source-path . --module MyFirstModule javac -d out\production --module-source-path . -m MyFirstModule	When you compile using --module, you must also specify --module-source-path.
javac	-p --module-path	javac -d out\production -p . --module-source-path . -m MySecondModule	You use --module-path with javac when your code has a dependency on existing modules.
jar	-d --describe-module	jar --file MyFirstModule.jar --describe-module jar -f MyFirstModule.jar -d	The --describe-module option for the jar command is similar to the java one, but includes the main-class as well.