IntelliJ can t recognize JavaFX 11 with OpenJDK 11

Question

I m having trouble getting IntellJ to recognize JavaFX packages  With a new JavaFX project  with OpenJDK 11  when trying to build the project  IntelliJ can t recognize the JavaFX packages   I ve imported openjfx javafx-base-11 from the Maven repo   I ve looked at other questions and the solutions seem to range from checking that the bytecode is at the right level  mine is   and that the project language is correct  mine is    Anyone have any ideas         Edit   Error

User · Answer

Quick summary  you can do either    Include the JavaFX modules via --module-path and --add-modules like in Jos   s answer   OR Once you have JavaFX libraries added to your project  either manually or via maven gradle import   add the module-info java file similar to the one specified in this answer    Note that this solution makes your app modular  so if you use other libraries  you will also need to add statements to require their modules inside the module-info java file       This answer is a supplement to Jose s answer   The situation is this    You are using a recent Java version  e g  13  You have a JavaFX application as a Maven project  In your Maven project you have the JavaFX plugin configured and JavaFX dependencies setup as per Jose s answer  You go to the source code of your main class which extends Application  you right-click on it and try to run it  You get an IllegalAccessError involving an  unnamed module  when trying to launch the app    Excerpt for a stack trace generating an IllegalAccessError when trying to run a JavaFX app from Intellij Idea   Exception in Application start method java lang reflect InvocationTargetException     at java base jdk internal reflect NativeMethodAccessorImpl invoke0 Native Method      at java base jdk internal reflect NativeMethodAccessorImpl invoke NativeMethodAccessorImpl java 62      at java base jdk internal reflect DelegatingMethodAccessorImpl invoke DelegatingMethodAccessorImpl java 43      at java base java lang reflect Method invoke Method java 567      at javafx graphics com sun javafx application LauncherImpl launchApplicationWithArgs LauncherImpl java 464      at javafx graphics com sun javafx application LauncherImpl launchApplication LauncherImpl java 363      at java base jdk internal reflect NativeMethodAccessorImpl invoke0 Native Method      at java base jdk internal reflect NativeMethodAccessorImpl invoke NativeMethodAccessorImpl java 62      at java base jdk internal reflect DelegatingMethodAccessorImpl invoke DelegatingMethodAccessorImpl java 43      at java base java lang reflect Method invoke Method java 567      at java base sun launcher LauncherHelper FXHelper main LauncherHelper java 1051  Caused by  java lang RuntimeException  Exception in Application start method     at javafx graphics com sun javafx application LauncherImpl launchApplication1 LauncherImpl java 900      at javafx graphics com sun javafx application LauncherImpl lambda launchApplication 2 LauncherImpl java 195      at java base java lang Thread run Thread java 830  Caused by  java lang IllegalAccessError  class com sun javafx fxml FXMLLoaderHelper  in unnamed module  0x45069d0e  cannot access class com sun javafx util Utils  in module javafx graphics  because module javafx graphics does not export com sun javafx util to unnamed module  0x45069d0e     at com sun javafx fxml FXMLLoaderHelper  lt clinit gt  FXMLLoaderHelper java 38      at javafx fxml FXMLLoader  lt clinit gt  FXMLLoader java 2056      at org jewelsea demo javafx springboot Main start Main java 13      at javafx graphics com sun javafx application LauncherImpl lambda launchApplication1 9 LauncherImpl java 846      at javafx graphics com sun javafx application PlatformImpl lambda runAndWait 12 PlatformImpl java 455      at javafx graphics com sun javafx application PlatformImpl lambda runLater 10 PlatformImpl java 428      at java base java security AccessController doPrivileged AccessController java 391      at javafx graphics com sun javafx application PlatformImpl lambda runLater 11 PlatformImpl java 427      at javafx graphics com sun glass ui InvokeLaterDispatcher Future run InvokeLaterDispatcher java 96  Exception running application org jewelsea demo javafx springboot Main   OK  now you are kind of stuck and have no clue what is going on   What has actually happened is this    Maven has successfully downloaded the JavaFX dependencies for your application  so you don t need to separately download the dependencies or install a JavaFX SDK or module distribution or anything like that  Idea has successfully imported the modules as dependencies to your project  so everything compiles OK and all of the code completion and everything works fine    So it seems everything should be OK  BUT  when you run your application  the code in the JavaFX modules is failing when trying to use reflection to instantiate instances of your application class  when you invoke launch  and your FXML controller classes  when you load FXML    Without some help  this use of reflection can fail in some cases  generating the obscure IllegalAccessError   This is due to a Java module system security feature which does not allow code from other modules to use reflection on your classes unless you explicitly allow it  and the JavaFX application launcher and FXMLLoader both require reflection in their current implementation in order for them to function correctly    This is where some of the other answers to this question  which reference module-info java  come into the picture   So let s take a crash course in Java modules    https   www baeldung com java-9-modularity   The key part is this      4 9  Opens      If we need to allow reflection of private types  but we don t want all   of our code exposed  we can use the opens directive to expose specific   packages       But remember  this will open the package up to the entire world  so   make sure that is what you want   module my module   opens com my package       So  perhaps you don t want to open your package to the entire world  then you can do      4 10  Opens     To      Okay  so reflection is great sometimes  but we still want as much security as we can get from encapsulation  We can selectively open our packages to a pre-approved list of modules  in this case  using the opens   to directive       module my module           opens com my package to moduleOne  moduleTwo  etc            So  you end up creating a src main java module-info java class which looks like this   module org jewelsea demo javafx springboot       requires javafx fxml      requires javafx controls      requires javafx graphics      opens org jewelsea demo javafx springboot to javafx graphics javafx fxml      Where  org jewelsea demo javafx springboot is the name of the package which contains the JavaFX Application class and JavaFX Controller classes  replace this with the appropriate package name for your application    This tells the Java runtime that it is OK for classes in the javafx graphics and javafx fxml to invoke reflection on the classes in your org jewelsea demo javafx springboot package  Once this is done  and the application is compiled and re-run things will work fine and the IllegalAccessError generated by JavaFX s use of reflection will no longer occur   But what if you don t want to create a module-info java file  If instead of using the the Run button in the top toolbar of IDE to run your application class directly  you instead    Went to the Maven window in the side of the IDE  Chose the javafx maven plugin target javafx run  Right-clicked on that and chose either Run Maven Build or Debug       Then the app will run without the module-info java file   I guess this is because the maven plugin is smart enough to dynamically include some kind of settings which allows the app to be reflected on by the JavaFX classes even without a module-info java file  though I don t know how this is accomplished   To get that setting transferred to the Run button in the top toolbar  right-click on the javafx run Maven target and choose the option to Create Run Debug Configuration for the target   Then you can just choose Run from the top toolbar to execute the Maven target

User · Answer

The issue that JavaFX is no longer part of JDK 11. The following solution works using IntelliJ (haven't tried it with NetBeans):

Add JavaFX Global Library as a dependency:

Settings -> Project Structure -> Module. In module go to the Dependencies tab, and click the add "+" sign -> Library -> Java-> choose JavaFX from the list and click Add Selected, then Apply settings.
Right click source file (src) in your JavaFX project, and create a new module-info.java file. Inside the file write the following code :
```
module YourProjectName { 
    requires javafx.fxml;
    requires javafx.controls;
    requires javafx.graphics;
    opens sample;
}
```
These 2 steps will solve all your issues with JavaFX, I assure you.

Reference : There's a You Tube tutorial made by The Learn Programming channel, will explain all the details above in just 5 minutes. I also recommend watching it to solve your problem: https://www.youtube.com/watch?v=WtOgoomDewo

User · Answer

As mentioned in the comments  the Starting Guide is the place to start with Java 11 and JavaFX 11   The key to work as you did before Java 11 is to understand that    JavaFX 11 is not part of the JDK anymore You can get it in different flavors  either as an SDK or as regular dependencies  maven gradle   You will need to include it to the module path of your project  even if your project is not modular    JavaFX project  If you create a regular JavaFX default project in IntelliJ  without Maven or Gradle  I d suggest you download the SDK from here  Note that there are jmods as well  but for a non modular project the SDK is preferred   These are the easy steps to run the default project    Create a JavaFX project Set JDK 11  point to your local Java 11 version  Add the JavaFX 11 SDK as a library  The URL could be something like  Users  lt user gt  Downloads javafx-sdk-11 lib   Once you do this you will notice that the JavaFX classes are now recognized in the editor       Before you run the default project  you just need to add these to the VM options    --module-path  Users  lt user gt  Downloads javafx-sdk-11 lib --add-modules javafx controls javafx fxml Run   Maven  If you use Maven to build your project  follow these steps    Create a Maven project with JavaFX archetype Set JDK 11  point to your local Java 11 version  Add the JavaFX 11 dependencies     lt dependencies gt       lt dependency gt           lt groupId gt org openjfx lt  groupId gt           lt artifactId gt javafx-controls lt  artifactId gt           lt version gt 11 lt  version gt       lt  dependency gt       lt dependency gt           lt groupId gt org openjfx lt  groupId gt           lt artifactId gt javafx-fxml lt  artifactId gt           lt version gt 11 lt  version gt       lt  dependency gt   lt  dependencies gt     Once you do this you will notice that the JavaFX classes are now recognized in the editor     You will notice that Maven manages the required dependencies for you  it will add javafx base and javafx graphics for javafx controls  but most important  it will add the required classifier based on your platform  In my case  Mac   This is why your jars org openjfx javafx-controls 11 are empty  because there are three possible classifiers  windows  linux and mac platforms   that contain all the classes and the native implementation   In case you still want to go to your  m2 repo and take the dependencies from there manually  make sure you pick the right one  for instance  m2 repository org openjfx javafx-controls 11 javafx-controls-11-mac jar    Replace default maven plugins with those from here  Run mvn compile javafx run  and it should work    Similar works as well for Gradle projects  as explained in detail here   EDIT  The mentioned Getting Started guide contains updated documentation and sample projects for IntelliJ    JavaFX 11 without Maven Gradle  see non-modular sample or modular sample projects  JavaFX 11 with Maven  see non-modular sample or modular sample projects  JavaFX 11 with Gradle  see non-modular sample or modular sample projects

User · Answer

None of the above worked for me  I spent too much time clearing other errors that came up  I found this to be the easiest and the best way    This works for getting JavaFx on Jdk 11  12  amp  on OpenJdk12 too    The Video shows you the JavaFx Sdk download How to set it as a Global Library Set the module-info java  i prefer the bottom one      module thisIsTheNameOfYourProject       requires javafx fxml      requires javafx controls      requires javafx graphics      opens sample        The entire thing took me only 5mins

[java] IntelliJ can't recognize JavaFX 11 with OpenJDK 11

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