--- title: JavaOne 2015: Under The Hood Of Project Jigsaw | daily.dev description: A detailed summary of Alex Buckley's JavaOne 2015 talk on the internals of Project Jigsaw (Java Platform Module System). Covers how strong encapsulation works... canonical: https://daily.dev/posts/javaone-2015-under-the-hood-of-project-jigsaw-4bhsipjgo twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: JavaOne 2015: Under The Hood Of Project Jigsaw | daily.dev og:description: A detailed summary of Alex Buckley's JavaOne 2015 talk on the internals of Project Jigsaw (Java Platform Module System). Covers how strong encapsulation works... og:url: https://daily.dev/posts/javaone-2015-under-the-hood-of-project-jigsaw-4bhsipjgo og:image: https://api.daily.dev/og/posts/4bhsIPJGo.png og:image:alt: JavaOne 2015: Under The Hood Of Project Jigsaw og:image:width: 1200 og:image:height: 630 og:locale: en --- > ## Documentation Index > Fetch the complete documentation index at: https://daily.dev/llms.txt > Use this file to discover all available pages before exploring further. # JavaOne 2015: Under The Hood Of Project Jigsaw **[nipafx \(Nicolai Parlog\)](https://daily.dev/sources/nipafx)** · 9 min read · 0 upvotes · 0 comments ## Summary A detailed summary of Alex Buckley's JavaOne 2015 talk on the internals of Project Jigsaw (Java Platform Module System). Covers how strong encapsulation works independently of class loaders, the three module types (named, unnamed, automatic), readability and accessibility rules, and the concept of layers. Key points include: public no longer means universally accessible, reflection respects module boundaries, automatic modules serve as a migration bridge, and layers allow frameworks to manage multiple module versions at runtime without disrupting class loader hierarchies. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: --- Tags: [#java](https://daily.dev/tags/java) [View this post on daily.dev](https://daily.dev/posts/javaone-2015-under-the-hood-of-project-jigsaw-4bhsipjgo) ```json {"@context":"https://schema.org","@graph":[{"@type":"Organization","@id":"https://daily.dev/#organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180},"sameAs":["https://twitter.com/dailydotdev","https://github.com/dailydotdev","https://www.linkedin.com/company/daily-dev-ltd"]},{"@type":"WebSite","@id":"https://daily.dev/#website","url":"https://daily.dev","name":"daily.dev","publisher":{"@id":"https://daily.dev/#organization"},"potentialAction":{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https://daily.dev/search?q={search_term_string}"},"query-input":"required name=search_term_string"}}]} {"@context":"https://schema.org","@type":"TechArticle","headline":"JavaOne 2015: Under The Hood Of Project Jigsaw","url":"https://daily.dev/posts/javaone-2015-under-the-hood-of-project-jigsaw-4bhsipjgo","mainEntityOfPage":{"@type":"WebPage","@id":"https://daily.dev/posts/javaone-2015-under-the-hood-of-project-jigsaw-4bhsipjgo"},"datePublished":"2026-03-16T08:14:19.338Z","dateModified":"2026-03-16T08:28:55.723Z","description":"A detailed summary of Alex Buckley's JavaOne 2015 talk on the internals of Project Jigsaw (Java Platform Module System). Covers how strong encapsulation works...","image":"https://media.daily.dev/image/upload/f_auto,q_auto/v1/posts/276b69245941779b9d8264f5cf730f6a?_a=AQAEuop","thumbnailUrl":"https://media.daily.dev/image/upload/f_auto,q_auto/v1/posts/276b69245941779b9d8264f5cf730f6a?_a=AQAEuop","isAccessibleForFree":true,"articleSection":"nipafx (Nicolai Parlog)","inLanguage":"en","publisher":{"@type":"Organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180}},"author":{"@type":"Organization","name":"nipafx (Nicolai Parlog)","logo":"https://media.daily.dev/image/upload/s--H_Echo_u--/f_auto,q_auto/v1773648772/logos/nipafx?_a=BAMAMiiu0","url":"https://daily.dev/sources/nipafx"},"commentCount":0,"discussionUrl":"https://daily.dev/posts/javaone-2015-under-the-hood-of-project-jigsaw-4bhsipjgo","interactionStatistic":[{"@type":"InteractionCounter","interactionType":{"@type":"LikeAction"},"userInteractionCount":0},{"@type":"InteractionCounter","interactionType":{"@type":"CommentAction"},"userInteractionCount":0}],"keywords":"java","timeRequired":"PT9M"} {"@context":"https://schema.org","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https://daily.dev"},{"@type":"ListItem","position":2,"name":"nipafx (Nicolai Parlog)","item":"https://daily.dev/sources/nipafx"},{"@type":"ListItem","position":3,"name":"JavaOne 2015: Under The Hood Of Project Jigsaw"}]} ```