sybex-1Z0-829-chapter-12

Code and commands from OCP Oracle Certified Professional Java SE 17 Study Guide: Exam 1Z0-829 by Scott Selikoff and Jeanne Boyarsky

The code in chapter 12 (modules) is a lot of file creation. Additionally, the commands are hard to type in. Therefore we are providing a repository with the code from the book to facilitate running the example.

Also see:

• Our main book page

Below is an outline of the chapter and the commands. Note that in this github repo, the commands are one line so you can copy/paste them into your command line. In the book, we used multiple lines for ease in reading/studying.

Creating and Running a Modular Program

Creating the Files

See the feeding folder for module zoo.animal.feeding

Compiling our First Module

Compile program

javac --module-path mods -d feeding feeding/zoo/animal/feeding/*.java feeding/module-info.java

Alternate forms of javac command

javac -p mods -d feeding feeding/zoo/animal/feeding/*.java feeding/*.java

javac -p mods -d feeding feeding/zoo/animal/feeding/*.java feeding/module-info.java

javac -p mods -d feeding feeding/zoo/animal/feeding/Task.java feeding/module-info.java

javac -p mods -d feeding feeding/zoo/animal/feeding/Task.java feeding/*.java

Running our First Module

Run program

java --module-path feeding --module zoo.animal.feeding/zoo.animal.feeding.Task

Alternate form of java command

java -p feeding -m zoo.animal.feeding/zoo.animal.feeding.Task

Packaging our First Module

Create jar

jar -cvf mods/zoo.animal.feeding.jar -C feeding/ .

Run program from jar

java -p mods -m zoo.animal.feeding/zoo.animal.feeding.Task

Updating our Example for Multiple Modules

Updating the Feeding Module

See the feeding folder for module zoo.animal.feeding. Uncomment the commented out line in module-info.java

Re-compile:

javac -p mods -d feeding feeding/zoo/animal/feeding/*.java feeding/module-info.java

Re-package

jar -cvf mods/zoo.animal.feeding.jar -C feeding/ .

Creating a Care Module

See the care folder for module zoo.animal.care

Compile:

javac -p mods -d care care/zoo/animal/care/details/*.java care/zoo/animal/care/medical/*.java care/module-info.java

Package:

jar -cvf mods/zoo.animal.care.jar -C care/ .

Creating the Talks Module

See the talks folder for module zoo.animal.talks.

Compile:

javac -p mods -d talks talks/zoo/animal/talks/content/*.java talks/zoo/animal/talks/media/*.java talks/zoo/animal/talks/schedule/*.java talks/module-info.java

Package:

jar -cvf mods/zoo.animal.talks.jar -C talks/ .

Creating the Staff Module

See the staff folder for module zoo.staff.

Compile:

javac -p mods -d staff staff/zoo/staff/*.java staff/module-info.java

Package:

jar -cvf  mods/zoo.staff.jar -C staff/ .

Diving into the module-info file

Exporting a Package

In the module-info.java in the talks folder:

1. Uncomment exports zoo.animal.talks.content to zoo.staff;
2. Comment out exports zoo.animal.talks.content;

Requiring a Module Transitively

In the module-info.java in the care folder:

1. Uncomment requires transitive zoo.animal.feeding;
2. Comment out requires zoo.animal.feeding;

In the module-info.java in the talks folder:

1. Uncomment requires transitive zoo.animal.care;
2. Comment out requires zoo.animal.feeding;
3. Comment out requires zoo.animal.care;

In the module-info.java in the staff folder:

1. Comment out requires zoo.animal.feeding;
2. Comment out requires zoo.animal.care;

Opening a Package

Don't need to be able to use in examples for this exam

Creating a Service

Declaring the Service Provider Interface

Compile service provider interface module

javac -d serviceProviderInterfaceModule serviceProviderInterfaceModule/zoo/tours/api/*.java serviceProviderInterfaceModule/module-info.java

Create zoo.tours.api.jar for the service provider interface module

jar -cvf mods/zoo.tours.api.jar -C serviceProviderInterfaceModule/ .

Creating a Service Locator

Compile service locator module

javac -p mods -d serviceLocatorModule serviceLocatorModule/zoo/tours/reservations/*.java serviceLocatorModule/module-info.java

Create zoo.tours.reservations.jar for the service locator module

jar -cvf mods/zoo.tours.reservations.jar -C serviceLocatorModule/ .

Invoking from a Consumer

Compile consumer module

javac -p mods -d consumerModule consumerModule/zoo/visitor/*.java consumerModule/module-info.java

Create zoo.visitor.jar for the visitor module

jar -cvf mods/zoo.visitor.jar -C consumerModule/ .

Run Tourist class

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

Adding a Service Provider

Compile service provider module

javac -p mods -d serviceProviderModule serviceProviderModule/zoo/tours/agency/*.java serviceProviderModule/module-info.java

Create zoo.tours.agency.jar for the service provider module

jar -cvf mods/zoo.tours.agency.jar -C serviceProviderModule/ .

Run Tourist class

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

Discovering Modules

java

Describing a module:

java -p mods -d zoo.animal.feeding

Alternate form of describing a module

java -p mods --describe-module zoo.animal.feeding

Listing available modules in JDK:

java --list-modules

Listing available modules including ours:

java -p mods --list-modules

Showing Module Resolution:

java --show-module-resolution -p feeding -m zoo.animal.feeding/zoo.animal.feeding.Task

jar

Describing a module:

jar -f mods/zoo.animal.feeding.jar -d

Alternate form of describing a module:

jar --file mods/zoo.animal.feeding.jar --describe-module

jmod

Don't need to be able to use in examples for this exam

jdeps

Compile Dino jar

javac zoo/dinos/*.java

Create zoo.dino.jar for Dino module

jar -cvf zoo.dino.jar .

Run jdeps command

jdeps zoo.dino.jar

Get jdeps summary

jdeps -s zoo.dino.jar
jdeps -summary zoo.dino.jar

List internal APIs

jdeps --jdk-internals zoo.dino.jar

jlink

Create Java runtime image

jlink --module-path mods --add-modules zoo.animal.talks --output zooApp