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Building modular applications with the Java Platform Module System and Layrry
This document discusses Layrry, a tool that uses Java Platform Module System layers to address some issues with modularizing applications. It allows adding modules at runtime, mapping dependency coordinates to modules, and preventing non-exported package collisions. The document provides an overview of Layrry's features like external configuration, parameterization, local and remote repositories, plugin architectures, and future plans. It includes links to GitHub and blog posts with more information.
Building modular applications with the Java Platform Module System and Layrry
- 1. @aalmiray | andresalmiray.com Buildingmodular applications with the Java Platform Module System and Layrry
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- 3. Andres Almiray Seasoned Sourceror @ Oracle ApacheGroovy PMC Java Champion Hackergarten github.com/aalmiray
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- 6. @aalmiray | andresalmiray.com JavaPlatform Module System
- 7. @aalmiray | andresalmiray.com JavaPlatform Module System • Also known by its project nickname: Jigsaw • Introduced in Java 9 • Designed to break down the JVM monolith • Applicable to user space as well • The promise is to give developers better code encapsulation and design foundations
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- 9. @aalmiray | andresalmiray.com Someuser statements • It only allows for one version of a module • It doesn’t allow adding modules at runtime • I have to modularize ALL dependencies to reap the benefits of the Java Platform Module System • It’s so hard to map dependency coordinates to module dependencies • Help, non-exported packages of different modules collide!
- 12. @aalmiray | andresalmiray.com Whatno one ever said “Let’s use Module Layers to tackle (some of) these issues”
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- 14. @aalmiray | andresalmiray.com Usingthe Layers API
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- 18. Gunnar Morling Open Source Software Engineer @RedHat Java Champion Lead of Debezium Bean Validation 2.0 Spec Lead morling.dev
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- 28. $ java -jarlayrry-launcher-1.0.0.Alpha1-all.jar —layers-config javafx.toml —properties versions.properties
- 29. $ sdk installlayrry 1.0.0.Alpha1 $ layrry —layers-config javafx.toml —properties versions.properties
- 30. $ sdk installjbang $ jbang layrry@moditect —layers-config javafx.toml —properties versions.properties
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- 32. Local Repositories • Artifactscan be organized in a local repository that does not require remote resolution • Two layouts currently supported
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- 35. @aalmiray | andresalmiray.com RemoteLayers • Layer configuration (and properties) files hosted at remote locations. • Mixing remote and local repositories is allowed. • Supports dynamic plugins, plugin directories can only be local.
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- 37. 1 package org.moditect.layrry.platform; 2 3/** 4 * Implementations get notified about the 5 * addition or removal of plug-in layers. 6 * Retrieved via the service loader API. 7 */ 8 public interface PluginLifecycleListener { 9 10 void pluginAdded(PluginDescriptor plugin); 11 12 void pluginRemoved(PluginDescriptor plugin); 13 }
- 38. 1 @Override 2 publicvoid pluginAdded(PluginDescriptor plugin) { 3 ServiceLoader<MyService> services = ServiceLoader.load( 4 plugin.getModuleLayer(), MyService.class); 5 6 services.forEach(service -> { 7 // only process services declared by the added layer itself, 8 // but not from ancestor layers 9 if (service.getClass().getModule().getLayer() == layer) { 10 // process service ... 11 } 12 }); 13 }
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- 46. @aalmiray | andresalmiray.com Future •Binary distributions: Homebrew, Snap, Chocolatey, etc. • Ability to create self-contained distributions (e.g. jlink, Capsule) • Derive layers from pom.xml? • Programmatic plug-in API • More JFR events for diagnostics • Your contributions?!
- 47. @aalmiray | andresalmiray.com Resources •https://github.com/moditect/layrry/ • https://github.com/moditect/layrry-examples/
- 48. @aalmiray | andresalmiray.com Resources •https://www.morling.dev/blog/introducing-layrry-runner- and-api-for-modularized-java-applications/ • https://www.morling.dev/blog/plugin-architectures-with- layrry-and-the-java-module-system/ • https://www.morling.dev/blog/class-unloading-in-layered- java-applications/ • http://andresalmiray.com/layrry-1-0-0-alpha1-has-been- released/
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