[FIXED] Cannot access javafx.collections.ObservableList

Issue

I'm creating a JavaFX application. I started developing it using local SDK and now I was trying to use Gradle. I created the build.gradle as follows:

plugins {
    id 'java'
    id 'application'
    id 'org.openjfx.javafxplugin' version '0.0.10'
}

application {
    mainClassName='Main.GUI.Main'
}

dependencies {
    implementation 'org.controlsfx:controlsfx:11.1.0'
    implementation 'org.apache.derby:derby:10.15.2.0'
}

javafx {
    version = "17.0.1"
    modules = [ 'javafx.controls', 'javafx.fxml']
}

repositories {
    mavenCentral()
}

This is part of my code that throws the error javafx.collections.ObservableList:

package GUI;

import Main.Archive;
import Main.Document;
import Main.Node;
import javafx.fxml.FXML;
import javafx.fxml.Initializable;
import javafx.scene.control.TableColumn;
import javafx.scene.control.TableView;
import javafx.scene.control.TreeItem;
import javafx.scene.control.TreeView;

import java.net.URL;
import java.nio.file.Path;
import java.util.Date;
import java.util.List;
import java.util.ResourceBundle;


public class MainController implements Initializable
{

    @FXML private TreeView<Node> tagTree;
    @FXML private TableView<Document> fileTable;
    @FXML private TableColumn<Document, String> name;
    @FXML private TableColumn<Document, Date> date;
    @FXML private TableColumn<Document, Integer> size;
    @FXML private TableColumn<Document, Path> path;

    private static Archive archive;
    private static Main mainApp;

    public void setMainApp(Main mainApp){
        this.mainApp = mainApp;
    }

    @Override
    public void initialize(URL url, ResourceBundle resourceBundle) {
        if(tagTree!=null)
            setTagTree(archive.getTagTree());
    }

    public void setTagTree(Node tags){
        TreeItem rootItem = new TreeItem("Tags");
        if(tags.getChildren()!=null)
            for (Node n:tags.getChildren())
                addNodes(rootItem, n);
        tagTree.setRoot(rootItem);
    }

    // Recursively creates a TreeItem for each tag and adds it to its root
    void addNodes(TreeItem<String> rootItem, Node tags){
        List<Node> children = tags.getChildren();
        // If it's the last item just add it
        if(children.isEmpty())
            rootItem.getChildren().add(new TreeItem<>(tags.getData().getName()));    // HERE
        else{
            // Otherwise, add each child to the root
            TreeItem<String> son = new TreeItem(tags.getData().getName());
            for (Node n : children)
                addNodes(son, n);
            rootItem.getChildren().add(son);    // ALSO HERE
        }
    }

    public void setArchive(Archive archive){
        MainController.archive = archive;
    }

    @FXML
    private void logout(){
        archive.logout();
        System.exit(0);
    }

    @FXML
    private void addDocument(){
        mainApp.showAddDocument();
    }

    @FXML
    private void addTag(){

    }

}

I have similar problems also with javafx.util.Callback and javafx.event.EventTarget.

The error

Solution

As jewelsea said, the problem was the version. I was using 17.0.1, which doesn't exist, instead of 17.0.0.1.

Answered By - Filippo
Answer Checked By - Clifford M. (JavaFixing Volunteer)