JavaFX "toolkit not initialized" in one test class but not two others; where is the difference?

Question

Environment:

• Oracle JDK 1.8u31;
• Intellij IDEA 14.0.3;
• Mockito 1.10.17;
• TestNG 6.8.13.

First, a quick goal about the architecture: what JavaFX calls a "controller" I call a display, and I have a view class which controls the elements of the display.

All such views inherit a common base class:

public abstract class JavafxView<P, D extends JavafxDisplay<P>>
{
    protected final Node node;
    protected final D display;

    protected JavafxView(final String fxmlLocation)
        throws IOException
    {
        final URL url = JavafxView.class.getResource(fxmlLocation);
        if (url == null)
            throw new IOException(fxmlLocation + ": resource not found");
        final FXMLLoader loader = new FXMLLoader(url);
        node = loader.load();
        display = loader.getController();
    }

    @SuppressWarnings("unchecked")
    @NonFinalForTesting
    public <T extends Node> T getNode()
    {
        return (T) node;
    }

    @NonFinalForTesting
    public D getDisplay()
    {
        return display;
    }
}

At first I had a problem when I started testing since I would get that "toolkit not initialized" each and every time. However, after asking the question I was provided with a solution which worked pretty well; I could now write tests to test the behavior without a problem...

Except that I now stumble upon a test in which I get this error again:

java.lang.ExceptionInInitializerError
    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
    at java.lang.reflect.Constructor.newInstance(Constructor.java:408)
    at java.lang.Class.newInstance(Class.java:438)
    at sun.reflect.misc.ReflectUtil.newInstance(ReflectUtil.java:51)
    at javafx.fxml.FXMLLoader$InstanceDeclarationElement.constructValue(FXMLLoader.java:1001)
    at javafx.fxml.FXMLLoader$ValueElement.processStartElement(FXMLLoader.java:742)
    at javafx.fxml.FXMLLoader.processStartElement(FXMLLoader.java:2701)
    at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:2521)
    at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:2435)
    at javafx.fxml.FXMLLoader.load(FXMLLoader.java:2403)
    at com.github.fge.grappa.debugger.javafx.JavafxView.<init>(JavafxView.java:24)
    at com.github.fge.grappa.debugger.csvtrace.tabs.matches.JavafxMatchesTabView.<init>(JavafxMatchesTabView.java:24)
    at com.github.fge.grappa.debugger.csvtrace.tabs.matches.JavafxMatchesTabViewTest.init(JavafxMatchesTabViewTest.java:28)
    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:483)
    at org.testng.internal.MethodInvocationHelper.invokeMethod(MethodInvocationHelper.java:84)
    at org.testng.internal.Invoker.invokeConfigurationMethod(Invoker.java:564)
    at org.testng.internal.Invoker.invokeConfigurations(Invoker.java:213)
    at org.testng.internal.Invoker.invokeMethod(Invoker.java:653)
    at org.testng.internal.Invoker.invokeTestMethod(Invoker.java:901)
    at org.testng.internal.Invoker.invokeTestMethods(Invoker.java:1231)
    at org.testng.internal.TestMethodWorker.invokeTestMethods(TestMethodWorker.java:127)
    at org.testng.internal.TestMethodWorker.run(TestMethodWorker.java:111)
    at org.testng.TestRunner.privateRun(TestRunner.java:767)
    at org.testng.TestRunner.run(TestRunner.java:617)
    at org.testng.SuiteRunner.runTest(SuiteRunner.java:348)
    at org.testng.SuiteRunner.runSequentially(SuiteRunner.java:343)
    at org.testng.SuiteRunner.privateRun(SuiteRunner.java:305)
    at org.testng.SuiteRunner.run(SuiteRunner.java:254)
    at org.testng.SuiteRunnerWorker.runSuite(SuiteRunnerWorker.java:52)
    at org.testng.SuiteRunnerWorker.run(SuiteRunnerWorker.java:86)
    at org.testng.TestNG.runSuitesSequentially(TestNG.java:1224)
    at org.testng.TestNG.runSuitesLocally(TestNG.java:1149)
    at org.testng.TestNG.run(TestNG.java:1057)
    at org.testng.remote.RemoteTestNG.run(RemoteTestNG.java:111)
    at org.testng.remote.RemoteTestNG.initAndRun(RemoteTestNG.java:204)
    at org.testng.remote.RemoteTestNG.main(RemoteTestNG.java:175)
    at org.testng.RemoteTestNGStarter.main(RemoteTestNGStarter.java:125)
    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:483)
    at com.intellij.rt.execution.application.AppMain.main(AppMain.java:134)
Caused by: java.lang.IllegalStateException: Toolkit not initialized
    at com.sun.javafx.application.PlatformImpl.runLater(PlatformImpl.java:270)
    at com.sun.javafx.application.PlatformImpl.runLater(PlatformImpl.java:265)
    at com.sun.javafx.application.PlatformImpl.setPlatformUserAgentStylesheet(PlatformImpl.java:540)
    at com.sun.javafx.application.PlatformImpl.setDefaultPlatformUserAgentStylesheet(PlatformImpl.java:502)
    at javafx.scene.control.Control.<clinit>(Control.java:87)
    ... 47 more

JavafxView.java:24 is this line:

node = loader.load();

However, that is not the most strange.

I have two other test classes testing two other JavafxView which work without a problem when I run the test classes individually; only this new test doesn't...

... But if I run the whole test suite instead of only that test then the test suceeds!

Here is the full source code of the test:

public class JavafxMatchesTabViewTest
{
    private JavafxMatchesTabView view;
    private MatchesTabDisplay display;

    @BeforeMethod
    public void init()
        throws IOException
    {
        view = new JavafxMatchesTabView();
        display = view.getDisplay();
    }

    @Test
    public void showMatchesTest()
    {
        final List<MatchStatistics> oldStats = Arrays.asList(
            mock(MatchStatistics.class),
            mock(MatchStatistics.class)
        );

        final List<MatchStatistics> newStats = Arrays.asList(
            mock(MatchStatistics.class),
            mock(MatchStatistics.class)
        );

        final TableView<MatchStatistics> tableView = spy(new TableView<>());
        display.matchesTable = tableView;

        final ObservableList<MatchStatistics> tableData = tableView.getItems();
        final ObservableList<TableColumn<MatchStatistics, ?>> sortOrder
            = tableView.getSortOrder();

        tableData.setAll(oldStats);
        sortOrder.clear();

        view.showMatches(newStats);

        assertThat(tableData).containsExactlyElementsOf(newStats);
        assertThat(sortOrder).containsExactly(display.nrCalls);
        verify(tableView).sort();
    }
}

So, uh, how do I fix that? At a first glance it would seem that the solution could be that I kind of "port" the custom MockMaker to a TestNG's @BeforeClass... Except that I don't see how I can really do that :/

Answer 1

Well, uh, it was more simple than I thought, and as is often the case I find the solution only once I've asked the question...

Anyway, the solution is to create an abstract base class which initializes the toolkit for you and it is as "easy" as this:

@Test
public abstract class JavafxViewTest
{
    @BeforeClass
    public static void initToolkit()
        throws InterruptedException
    {
        final CountDownLatch latch = new CountDownLatch(1);
        SwingUtilities.invokeLater(() -> {
            new JFXPanel(); // initializes JavaFX environment
            latch.countDown();
        });

        // That's a pretty reasonable delay... Right?
        if (!latch.await(5L, TimeUnit.SECONDS))
            throw new ExceptionInInitializerError();
    }
}