Project Jigsaw_ Florian Trobach whoami codecentric Karlsruhe - - PowerPoint PPT Presentation

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Project Jigsaw_ Florian Trobach whoami codecentric Karlsruhe - - PowerPoint PPT Presentation

Apr 01, 2023 120 likes •354 views

Project Jigsaw_ Florian Trobach whoami codecentric Karlsruhe Plain Old Java Dev Currently trying to tame the SMACK stack 2 Services 3 Modules can provide services java.util.ServiceLoader 4 Modules can provide services

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Project Jigsaw_

Florian Troßbach

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whoami

  • codecentric Karlsruhe
  • Plain Old Java Dev
  • Currently trying to tame the

SMACK stack

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Services

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Modules can provide services

  • java.util.ServiceLoader

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Modules can provide services

  • Modules provide service implementations
  • Other modules can use services
  • ServiceLoader finds all implementations on the

module path

  • No dependency on the providing modules needed

=> decoupling!

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Example

6 module org.codefx.demo.advent { // list the required modules requires org.codefx.demo.advent.calendar; // list the used services uses org.codefx.demo.advent.surprise.SurpriseFactory; } module org.codefx.demo.advent.factory.quote { requires public org.codefx.demo.advent.surprise; // specify which class provides which service provides org.codefx.demo.advent.surprise.SurpriseFactory with org.codefx.demo.advent.factory.quote.QuoteFactory; }

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Example

7 Diagram by Nicolai Parlog, http://blog.codefx.org/java/dev/jigsaw-hands-on-guide/

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Working with non-modular code

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Non-modular code

  • Using libraries
  • Spring, Guava, …
  • your internal library
  • Using modular code from

non-modular code

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A u t

  • m

a t i c m

  • d

u l e s U n n a m e d m

  • d

u l e

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Automatic modules

What is the name of an automatic module?

  • The name of the jar
  • guava.jar => “guava”
  • guava-19.0.jar

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Automatic modules

What does an automatic module export?

  • All its packages
  • => All public types

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Automatic modules

What does an automatic module require?

  • All exports of all modules on the module

path

  • All public types in the unnamed module

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The unnamed module

What is the name of the unnamed module?

  • Any guesses?

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The unnamed module

What does the unnamed module export?

  • All its packages
  • requires unnamed;

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The unnamed module

What does an the unnamed module require?

  • All exports of all modules on the module

path

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Named Modules

Overview

16 [..].advent java.base [..].advent.surprise guava Unnamed module commons- io-2.4.0.jar commons-lang.jar

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Example

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Breaking Jigsaw - Live

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jlink

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Build your own JRE!

  • Create your own Java runtime
  • Pick which modules to include
  • Can lead to really small distributions (< 15 MB)

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Example

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Resources

  • https:/

/github.com/ftrossbach/demo-jigsaw-advent-calendar

  • Mark Reinhold, “The State of the Module System”
  • http:/

/openjdk.java.net/projects/jigsaw/spec/sotms/

  • Nicolai Parlog’s posts on Jigsaw
  • http:/

/blog.codefx.org/tag/project-jigsaw/

  • My blog posts on Jigsaw
  • https:/

/blog.codecentric.de/en/2015/11/first-steps-with-java9- jigsaw-part-1/

  • https:/

/blog.codecentric.de/en/2015/12/first-steps-with-java9- jigsaw-part-2/

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