Package-private or private declaration accessible would yield an exception: In addition to checking access violations during the compilation, it is alsoīetter enforced at runtime. Moreover, since modules are natively supported by the JVM itself, it isĪvailable not only to Java but to all other languages running on the JVM This effectively achieves the same as what the internal modifier does. Will not be visible to other modules, even if it is marked as public. In other words, anything not specified in the module-info.java file Using the module-info.java file, we can specify what packages a moduleĮxports. Project Jigsaw added the concept of modules as a first-class citizen to the JVM. Years later, the Java platform eventuallyĪddressed the issue in the project Jigsaw, which finally saw release as a part The internal modifier was most likely an answer to a problem that the Java The internal modifier even used to be the default visibility modifierįor quite some time if no modifier was stated explicitly, akin to Java’s Likely been there since Kotlin’s inception in 2011. Although I was not able to track down specific dates, it has Kotlin’s internal modifier existed for a long time before its first stable Unfortunately, there is nothing in the bytecode that would prevent the JavaĬompiler from accessing internal declarations, and the compiler will not evenįor the Java compiler, internal declarations are effectively public, whichīreaks the internal modifier. Perhaps the META-INF/.kotlin_module file too) to enforce Kotlin compiler uses the information stored in Metadata annotations (and Our goal is to protect the AdsManager class from being publicly accessed by Let’s go through the basic theory, just for the sake of completeness. Sensitive code since they do not really protect the code from being accessedīy code outside of the specified scope. Such as when and how ads are displayed, since consumers would most likely justĭisable them, causing you to lose revenue.Ī natural step would be to limit the visibility of the sensitive code but thatīoth Java’s package-private modifier and Kotlin’s internal modifier provideĪ false sense of encapsulation and should not be used as a means to hide The library should not provide a way for consumers to tinker with internals, But as an ads-driven company, you want to ensure adsĪre properly displayed in embedded video players as well. Imagine that you develop a commercial library.Īmong other features, the library should allow consumers to embed a video player

Kotlin internal modifier