Upgrade to java 16

.gitpod.Dockerfile

+FROM gitpod/workspace-full-vnc
+
+USER gitpod
+
+RUN bash -c ". /home/gitpod/.sdkman/bin/sdkman-init.sh \
+             && sdk install java 16.0.1.hs-adpt \
+             && sdk default java 16.0.1.hs-adpt"

.gitpod.yml

+image:
+  file: .gitpod.Dockerfile
+
+tasks:
+  - init: sdk use java 16.0.1.hs-adpt
+    command: cd javafx-template; mvn compile
+
+ports:
+  # used by virtual desktop and vnc, supports JavaFX
+  - port: 6080

javafx-template/.gitignore

+# ignore maven build folder
+target/

javafx-template/pom.xml

+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+    <groupId>it1901</groupId>
+    <artifactId>javafx-template</artifactId>
+    <version>0.0.1-SNAPSHOT</version>
+
+    <properties>
+        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+        <maven.compiler.source>16</maven.compiler.source>
+        <maven.compiler.target>16</maven.compiler.target>
+    </properties>
+
+    <dependencies>
+
+        <!-- javafx -->
+        <dependency>
+            <groupId>org.openjfx</groupId>
+            <artifactId>javafx-controls</artifactId>
+            <version>16</version>
+        </dependency>
+        <dependency>
+            <groupId>org.openjfx</groupId>
+            <artifactId>javafx-fxml</artifactId>
+            <version>16</version>
+        </dependency>
+
+        <!-- junit testing with jupiter -->
+        <dependency>
+            <groupId>org.junit.jupiter</groupId>
+            <artifactId>junit-jupiter-api</artifactId>
+            <version>5.7.2</version>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.junit.jupiter</groupId>
+            <artifactId>junit-jupiter-engine</artifactId>
+            <version>5.7.2</version>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.junit.jupiter</groupId>
+            <artifactId>junit-jupiter-params</artifactId>
+            <version>5.7.2</version>
+            <scope>test</scope>
+        </dependency>
+
+        <!-- test javafx with TextFX -->
+		<dependency>
+			<groupId>org.testfx</groupId>
+			<artifactId>testfx-core</artifactId>
+			<version>4.0.16-alpha</version>
+			<scope>test</scope>
+		</dependency>
+		<dependency>
+			<groupId>org.testfx</groupId>
+			<artifactId>testfx-junit5</artifactId>
+			<version>4.0.16-alpha</version>
+			<scope>test</scope>
+        </dependency>
+
+    </dependencies>
+
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-compiler-plugin</artifactId>
+                <version>3.8.1</version>
+                <configuration>
+                    <release>16</release>
+                </configuration>
+            </plugin>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+        		<artifactId>maven-surefire-plugin</artifactId>
+		        <version>3.0.0-M5</version>
+	        </plugin>
+
+            <plugin>
+                <groupId>org.openjfx</groupId>
+                <artifactId>javafx-maven-plugin</artifactId>
+                <version>0.0.6</version>
+                <executions>
+                    <execution>
+                        <!-- Default configuration for running -->
+                        <!-- Usage: mvn clean javafx:run -->
+                        <id>default-cli</id>
+                        <configuration>
+                            <mainClass>app.App</mainClass>
+                        </configuration>
+                    </execution>
+                </executions>
+            </plugin>
+        </plugins>
+    </build>
+</project>

javafx-template/src/main/java/app/App.java

+package groupid;
+
+import javafx.application.Application;
+import javafx.fxml.FXMLLoader;
+import javafx.scene.Parent;
+import javafx.scene.Scene;
+import javafx.stage.Stage;
+
+import java.io.IOException;
+
+/**
+ * JavaFX App
+ */
+public class App extends Application {
+
+    private static Scene scene;
+
+    @Override
+    public void start(Stage stage) throws IOException {
+        FXMLLoader fxmlLoader = new FXMLLoader(this.getClass().getResource("App.fxml"));
+        Parent parent = fxmlLoader.load();
+        stage.setScene(new Scene(parent));
+        stage.show();
+    }
+
+    public static void main(String[] args) {
+        launch();
+    }
+}
\ No newline at end of file

javafx-template/src/main/java/app/AppController.java

+package groupid;
+
+import java.io.IOException;
+import javafx.fxml.FXML;
+
+public class AppController {
+
+    @FXML
+    private void switchToSecondary() throws IOException {
+    }
+}

javafx-template/src/main/resources/app/App.fxml

+<?xml version="1.0" encoding="UTF-8"?>
+
+<?import javafx.scene.layout.VBox?>
+<?import javafx.scene.control.Label?>
+<?import javafx.scene.control.Button?>
+<?import javafx.geometry.Insets?>
+
+<VBox alignment="CENTER" spacing="20.0" xmlns="http://javafx.com/javafx/8.0.171" xmlns:fx="http://javafx.com/fxml/1" fx:controller="app.AppController">
+   <children>
+      <Label text="Primary View" />
+      <Button fx:id="primaryButton" text="Switch to Secondary View" onAction="#switchToSecondary"/>
+   </children>
+   <padding>
+      <Insets bottom="20.0" left="20.0" right="20.0" top="20.0" />
+   </padding>
+</VBox>