JavaFX + maven + TestFX + monocle don't work together

Question

I have a small project for demonsration JavaFX + TestFX under maven. I use:

1. Java(TM) SE Runtime Environment (build 1.8.0_40-b26)
2. Apache Maven 3.2.5 (12a6b3acb947671f09b81f49094c53f426d8cea1; 2014-12-14T21:29:23+04:00)

Full source: https://github.com/alevohin/testfx-maven-example

I have 2 problems that I cannot resolve:

1) When I start AppFXTest from IDE (IDEA), test fails with

java.lang.ClassNotFoundException: com.sun.glass.ui.monocle.MonoclePlatformFactory
at java.net.URLClassLoader.findClass(URLClassLoader.java:381)
at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:264)
at com.sun.glass.ui.PlatformFactory.getPlatformFactory(PlatformFactory.java:42)
at com.sun.glass.ui.Application.run(Application.java:146)
at com.sun.javafx.tk.quantum.QuantumToolkit.startup(QuantumToolkit.java:263)
at com.sun.javafx.application.PlatformImpl.startup(PlatformImpl.java:211)
at com.sun.javafx.application.LauncherImpl.startToolkit(LauncherImpl.java:675)
at com.sun.javafx.application.LauncherImpl.launchApplication1(LauncherImpl.java:695)
at com.sun.javafx.application.LauncherImpl.lambda$launchApplication$152(LauncherImpl.java:182)
at com.sun.javafx.application.LauncherImpl$$Lambda$4/367732825.run(Unknown Source)
at java.lang.Thread.run(Thread.java:745)
Failed to load Glass factory class

It works if I disable Monocle. But I see real JavaFX window and real cursor clicking buttons ("non-headless" mode)

2) When I try to execute test (evecute mvn clean test) via maven I get another error

[ERROR] Failed to execute goal org.apache.maven.plugins:maven-surefire-plugin:2.18.1:test (default-test) on project testfx-maven-example: Execution default-test of goal org.apache.maven.plugins:maven-surefire-plugin:2.18.1:test failed: java.lang.NoClassDefFoundError: javafx/stage/Stage: javafx.stage.Stage -> [Help 1]
org.apache.maven.lifecycle.LifecycleExecutionException: Failed to execute goal org.apache.maven.plugins:maven-surefire-plugin:2.18.1:test (default-test) on project testfx-maven-example: Execution default-test of goal org.apache.maven.plugins:maven-surefire-plugin:2.18.1:test failed: java.lang.NoClassDefFoundError: javafx/stage/Stage
at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:224)
at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:153)
at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:145)
at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:116)
at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:80)
at org.apache.maven.lifecycle.internal.builder.singlethreaded.SingleThreadedBuilder.build(SingleThreadedBuilder.java:51)
at org.apache.maven.lifecycle.internal.LifecycleStarter.execute(LifecycleStarter.java:120)
at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:355)
at org.apache.maven.DefaultMaven.execute(DefaultMaven.java:155)
at org.apache.maven.cli.MavenCli.execute(MavenCli.java:584)
at org.apache.maven.cli.MavenCli.doMain(MavenCli.java:216)
at org.apache.maven.cli.MavenCli.main(MavenCli.java:160)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:497)
at org.codehaus.plexus.classworlds.launcher.Launcher.launchEnhanced(Launcher.java:289)
at org.codehaus.plexus.classworlds.launcher.Launcher.launch(Launcher.java:229)
at org.codehaus.plexus.classworlds.launcher.Launcher.mainWithExitCode(Launcher.java:415)
at org.codehaus.plexus.classworlds.launcher.Launcher.main(Launcher.java:356)
at org.codehaus.classworlds.Launcher.main(Launcher.java:47)
...
Caused by: java.lang.ClassNotFoundException: javafx.stage.Stage
at java.net.URLClassLoader.findClass(URLClassLoader.java:381)
at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
at org.apache.maven.surefire.booter.IsolatedClassLoader.loadClass(IsolatedClassLoader.java:97)
... 48 more

My pom.xml looks like

<?xml version="1.0"?>
<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/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <groupId>com.alevohin</groupId>
    <artifactId>testfx-maven-example</artifactId>
    <version>1.0-SNAPSHOT</version>
    <url>https://github.com/alevohin/javafx-maven-example</url>
    <dependencies>
        <dependency>
            <groupId>org.hamcrest</groupId>
            <artifactId>hamcrest-all</artifactId>
            <version>1.3</version>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.10</version>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.mockito</groupId>
            <artifactId>mockito-all</artifactId>
            <version>1.9.0</version>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.testfx</groupId>
            <artifactId>testfx-core</artifactId>
            <version>4.0.1-alpha</version>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.testfx</groupId>
            <artifactId>testfx-junit</artifactId>
            <version>4.0.1-alpha</version>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.jfxtras</groupId>
            <artifactId>openjfx-monocle</artifactId>
            <version>1.8.0_20</version>
            <scope>test</scope>
        </dependency>
    </dependencies>
    <build>
        <plugins>
            <plugin>
                <artifactId>maven-compiler-plugin</artifactId>
                <configuration>
                    <source>1.7</source>
                    <target>1.7</target>
                </configuration>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-surefire-plugin</artifactId>
                <version>2.18.1</version>
                <configuration>
                    <forkCount>1</forkCount>
                    <reuseForks>false</reuseForks>
                    <threadCount>1</threadCount>
                    <systemPropertyVariables>
                        <glass.platform>Monocle</glass.platform>
                        <monocle.platform>Headless</monocle.platform>
                        <prism.order>sw</prism.order>
                    </systemPropertyVariables>
                </configuration>
            </plugin>
        </plugins>
    </build>
</project>

AppFXTest

public final class AppFXTest extends ApplicationTest {

    @Override
    public void start(final Stage stage) throws Exception {
        new AppFX().start(stage);
    }

    @Test
    public void showsButtons() throws Exception {
        MatcherAssert.assertThat(
            lookup(".button").queryAll().size(),
            Matchers.is(2)
        );
    }

    @Test
    public void showsBottom() throws Exception {
        final Label label = lookup("BOTTOM").queryFirst();
        MatcherAssert.assertThat(
            label.isVisible(),
            Matchers.is(true)
        );
    }

    @Test
    public void clicksButtons() throws Exception {
        clickOn("A").clickOn("B");
    }
}

App

public final class AppFX extends Application {

    /**
     * Program entry point.
     * @param args Program arguments.
     */
    public static void main(final String... args) {
        Application.launch(AppFX.class, args);
    }

    @Override
    public void start(final Stage stage) throws Exception {
        stage.setTitle("TEST");
        final Scene scene = new Scene(this.centralPane());
        scene.getStylesheets().add(
            AppFX.class.getResource("App.css").toExternalForm()
        );
        stage.setScene(scene);
        stage.setMinWidth(800.0D);
        stage.setMinHeight(600.0D);
        stage.show();
    }

    private Pane centralPane() {
        final BorderPane border = new BorderPane();
        border.setTop(this.buttonsPane());
        border.setCenter(this.centerPane());
        border.setBottom(this.bottomPane());
        return border;
    }

    private Pane buttonsPane() {
        final HBox controls = new HBox();
        controls.setSpacing(5.0D);
        controls.setAlignment(Pos.BASELINE_CENTER);
        controls.getChildren().add(new Label("BUTTONS"));
        controls.getChildren().add(new Button("A"));
        controls.getChildren().add(new Button("B"));
        return controls;
    }

    private Pane centerPane() {
        final VBox pane = new VBox();
        pane.setAlignment(Pos.CENTER);
        pane.getChildren().add(new Label("CENTER"));
        pane.setMinSize(600.0D, 400.0D);
        return pane;
    }

    private Pane bottomPane() {
        final VBox bottom = new VBox();
        final HBox status = new HBox();
        status.setAlignment(Pos.BASELINE_RIGHT);
        bottom.getChildren().add(status);
        status.getChildren().add(new Label("BOTTOM"));
        return bottom;
    }

}

UPDATED

Problem with

[ERROR] Failed to execute goal org.apache.maven.plugins:maven-surefire-plugin:2.18.1:test (default-test) on project testfx-maven-example: Execution default-test of goal org.apache.maven.plugins:maven-surefire-plugin:2.18.1:test failed: java.lang.NoClassDefFoundError: javafx/stage/Stage: javafx.stage.Stage -> [Help 1]

solved by adding to pom.xml additionalClasspathElements like this

 <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-surefire-plugin</artifactId>
                <version>2.18.1</version>
                <configuration>
                    ...
                    <additionalClasspathElements>
                        <additionalClasspathElement>${java.home}/lib/ext/jfxrt.jar</additionalClasspathElement>
                    </additionalClasspathElements>
                </configuration>
            </plugin>

Cangue

would ui4j fit the bill. It is fairly up to date? – Milligram

Answer 1

Failed to load Glass factory class

I used to have that error too, in my case i manually build the Monocle .jar and copied it to the JVM (jre/lib/ext).

Build Monocle according to the documentation on https://github.com/TestFX/Monocle, alternatively build it from the OpenJDK repository.

So the following worked for me:

• Copy the Monocle .jar you build to jre/lib/ext of your JDK.
• Run your application with the following JVM arguments:

-Dtestfx.robot=glass
-Dglass.platform=Monocle
-Dmonocle.platform=Headless
-Dprism.order=sw

The -Dtestfx.robot=glass is necessary, because TestFX otherwise uses the AWTRobot, which moves your mouse using the system event queue. Maybe that's enough of addition for your test to work properly.

Looking at your pom.xml, junit brings it's own version of hamcrest-core, so you should exclude that to avoid issues ( if you want to import several hamcrest matchers ). I used to have errors using both.

For further research, the link of which @ItachiUchiha provided and the post on https://zentrieredich.wordpress.com/2014/12/23/javafx-testen-mit-monocle/ helped me going the way with TestFX using Monocle.

Internecine

Why do you 'manually build the Monocle .jar and copy it to the JVM (jre/lib/ext)'? – Houseboat

This is by far the quickest, most comprehensive solution to getting Monocle configured I've found. I agree with @LeroyDunn, I'm curious if compilation was required. Here are some Monocle downloads on Maven Central: mvnrepository.com/artifact/org.testfx/openjfx-monocle. – Precede

The Wordpress post is no longer available. Here is the latest archived version from the Wayback Machine. – Secretarial

Answer 2

I would recommend to use TestFX 3.x because 4.x is still in alpha version.

A very nice blog about how to test your application and the working of TestFX is given in :

TestFX internals explained

For monocle usage, you can follow :

Headless UI Testing with TestFX and JavaFX 8

Dissimilarity

The first link does not work anymore. Here is the working link: TestFX internals explained – Secretarial

Answer 3

To get rid of with

java.lang.ClassNotFoundException: com.sun.glass.ui.monocle.MonoclePlatformFactory

instead of copy the Monocle .jar to the JVM (jre/lib/ext)), we can add .jar to our project and load the MonoclePlatformFactory class in runtime to the classpath like below:

static {
            try {
                File AGENT_JAR = new File("../lib/openjfx-monocle-1.8.0_20.jar");
                Method addUrl = URLClassLoader.class.getDeclaredMethod("addURL", URL.class);
                addUrl.setAccessible(true);
                addUrl.invoke(PlatformFactory.class.getClassLoader(), AGENT_JAR.toURI().toURL());
            } catch (Exception e) {
                e.printStackTrace();
            }
        }

Redwing

You need to explain your answer! – Hagiographa

Modern JDK's (JDK >=9) will throw some warnings when reflecting upon internal Java classes, but the solution does offer a nice trick to avoid messing with the jre/lib/ext. – Precede