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JavaFX with Junit

I would like to test methods that have JavaFX scene elements like TextField or DatePicker. I found here How do you unit test a JavaFX controller with JUnit how to run test for JavaFX app and it works fine for me if I have just one test class where Thread is initialized. But what about if I have two classes? I am not able to initialize the same thread with launch method because exception will be thrown. If I will not create thread in second test class there is also another exception. Below you can find test classes and stack trace. I was also thinking about stopping this thread in method with #AfterClass annotation and then starting it in second class again but I do not think it is possible. Does anyone can help me?
FirstTestClass
#RunWith(PowerMockRunner.class)
#PrepareForTest({TextField.class, DatePicker.class})
public class FirstTestClass {
#BeforeClass
public static void javaFXInitializer() throws SQLException, InterruptedException {
Thread thread = new Thread("JavaFX Init Thread") {
public void run() {
Application.launch(Main.class);
}
};
thread.setDaemon(true);
thread.start();
Thread.sleep(5000);
}
#Test
public void firstTest() {
TextField textFieldMock = mock(TextField.class);
DatePicker datePickerMock = mock(DatePicker.class);
TestClass objectUnderTest = new TestClass();
when(textFieldMock.getText()).thenReturn("2000");
when(datePickerMock.getValue()).thenReturn(LocalDate.of(1992,1,1));
//rest of code to test
}
}
SecondTestClass
#RunWith(PowerMockRunner.class)
#PrepareForTest({TextField.class, DatePicker.class})
public class SecondTestClass {
#BeforeClass
public static void javaFXInitializer() throws SQLException, InterruptedException {
Thread thread = new Thread("JavaFX Init Thread") {
public void run() {
Application.launch(Main.class);
}
};
thread.setDaemon(true);
thread.start();
Thread.sleep(5000);
}
#Test
public void firstTest() {
TextField textFieldMock = mock(TextField.class);
DatePicker datePickerMock = mock(DatePicker.class);
TestClass objectUnderTest = new TestClass();
when(textFieldMock.getText()).thenReturn("5000");
when(datePickerMock.getValue()).thenReturn(LocalDate.of(1990,1,1));
//rest of code to test
}
}
Exception when I initialize thread in two classes
Exception in thread "JavaFX IncomeTest Init Thread" java.lang.RuntimeException: java.lang.UnsatisfiedLinkError: Native Library C:\Program Files\Java\jdk1.8.0_144\jre\bin\glass.dll already loaded in another classloader
at com.sun.javafx.tk.quantum.QuantumToolkit.startup(QuantumToolkit.java:267)
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$155(LauncherImpl.java:182)
at java.lang.Thread.run(Thread.java:748)
Caused by: java.lang.UnsatisfiedLinkError: Native Library C:\Program Files\Java\jdk1.8.0_144\jre\bin\glass.dll already loaded in another classloader
at java.lang.ClassLoader.loadLibrary0(ClassLoader.java:1907)
at java.lang.ClassLoader.loadLibrary(ClassLoader.java:1824)
at java.lang.Runtime.load0(Runtime.java:809)
at java.lang.System.load(System.java:1086)
at com.sun.glass.utils.NativeLibLoader.loadLibraryFullPath(NativeLibLoader.java:201)
at com.sun.glass.utils.NativeLibLoader.loadLibraryInternal(NativeLibLoader.java:94)
at com.sun.glass.utils.NativeLibLoader.loadLibrary(NativeLibLoader.java:39)
at com.sun.glass.ui.Application.loadNativeLibrary(Application.java:112)
at com.sun.glass.ui.Application.loadNativeLibrary(Application.java:120)
at com.sun.glass.ui.win.WinApplication.access$300(WinApplication.java:39)
at com.sun.glass.ui.win.WinApplication$1.run(WinApplication.java:118)
at com.sun.glass.ui.win.WinApplication$1.run(WinApplication.java:91)
at java.security.AccessController.doPrivileged(Native Method)
at com.sun.glass.ui.win.WinApplication.<clinit>(WinApplication.java:91)
at com.sun.glass.ui.win.WinPlatformFactory.createApplication(WinPlatformFactory.java:39)
at com.sun.glass.ui.win.WinPlatformFactory.createApplication(WinPlatformFactory.java:36)
at com.sun.glass.ui.Application.run(Application.java:146)
at com.sun.javafx.tk.quantum.QuantumToolkit.startup(QuantumToolkit.java:257)
... 5 more
Exception when Thread is initialized only in first class
java.lang.ExceptionInInitializerError
at sun.reflect.GeneratedSerializationConstructorAccessor12.newInstance(Unknown Source)
at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
at org.objenesis.instantiator.sun.SunReflectionFactoryInstantiator.newInstance(SunReflectionFactoryInstantiator.java:45)
at org.objenesis.ObjenesisBase.newInstance(ObjenesisBase.java:73)
at org.mockito.internal.creation.instance.ObjenesisInstantiator.newInstance(ObjenesisInstantiator.java:14)
at org.powermock.api.mockito.repackaged.ClassImposterizer.createProxy(ClassImposterizer.java:149)
at org.powermock.api.mockito.repackaged.ClassImposterizer.imposterise(ClassImposterizer.java:64)
at org.powermock.api.mockito.internal.mockcreation.DefaultMockCreator.createMethodInvocationControl(DefaultMockCreator.java:121)
at org.powermock.api.mockito.internal.mockcreation.DefaultMockCreator.createMock(DefaultMockCreator.java:69)
at org.powermock.api.mockito.internal.mockcreation.DefaultMockCreator.mock(DefaultMockCreator.java:46)
at org.powermock.api.mockito.PowerMockito.mock(PowerMockito.java:141)
at
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:498)
at org.junit.internal.runners.TestMethod.invoke(TestMethod.java:68)
at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl$PowerMockJUnit44MethodRunner.runTestMethod(PowerMockJUnit44RunnerDelegateImpl.java:326)
at org.junit.internal.runners.MethodRoadie$2.run(MethodRoadie.java:89)
at org.junit.internal.runners.MethodRoadie.runBeforesThenTestThenAfters(MethodRoadie.java:97)
at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl$PowerMockJUnit44MethodRunner.executeTest(PowerMockJUnit44RunnerDelegateImpl.java:310)
at org.powermock.modules.junit4.internal.impl.PowerMockJUnit47RunnerDelegateImpl$PowerMockJUnit47MethodRunner.executeTestInSuper(PowerMockJUnit47RunnerDelegateImpl.java:131)
at org.powermock.modules.junit4.internal.impl.PowerMockJUnit47RunnerDelegateImpl$PowerMockJUnit47MethodRunner.access$100(PowerMockJUnit47RunnerDelegateImpl.java:59)
at org.powermock.modules.junit4.internal.impl.PowerMockJUnit47RunnerDelegateImpl$PowerMockJUnit47MethodRunner$TestExecutorStatement.evaluate(PowerMockJUnit47RunnerDelegateImpl.java:147)
at org.powermock.modules.junit4.internal.impl.PowerMockJUnit47RunnerDelegateImpl$PowerMockJUnit47MethodRunner.evaluateStatement(PowerMockJUnit47RunnerDelegateImpl.java:107)
at org.powermock.modules.junit4.internal.impl.PowerMockJUnit47RunnerDelegateImpl$PowerMockJUnit47MethodRunner.executeTest(PowerMockJUnit47RunnerDelegateImpl.java:82)
at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl$PowerMockJUnit44MethodRunner.runBeforesThenTestThenAfters(PowerMockJUnit44RunnerDelegateImpl.java:298)
at org.junit.internal.runners.MethodRoadie.runTest(MethodRoadie.java:87)
at org.junit.internal.runners.MethodRoadie.run(MethodRoadie.java:50)
at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl.invokeTestMethod(PowerMockJUnit44RunnerDelegateImpl.java:218)
at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl.runMethods(PowerMockJUnit44RunnerDelegateImpl.java:160)
at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl$1.run(PowerMockJUnit44RunnerDelegateImpl.java:134)
at org.junit.internal.runners.ClassRoadie.runUnprotected(ClassRoadie.java:34)
at org.junit.internal.runners.ClassRoadie.runProtected(ClassRoadie.java:44)
at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl.run(PowerMockJUnit44RunnerDelegateImpl.java:136)
at org.powermock.modules.junit4.common.internal.impl.JUnit4TestSuiteChunkerImpl.run(JUnit4TestSuiteChunkerImpl.java:121)
at org.powermock.modules.junit4.common.internal.impl.AbstractCommonPowerMockRunner.run(AbstractCommonPowerMockRunner.java:57)
at org.powermock.modules.junit4.PowerMockRunner.run(PowerMockRunner.java:59)
at org.apache.maven.surefire.junit4.JUnit4Provider.execute(JUnit4Provider.java:252)
at org.apache.maven.surefire.junit4.JUnit4Provider.executeTestSet(JUnit4Provider.java:141)
at org.apache.maven.surefire.junit4.JUnit4Provider.invoke(JUnit4Provider.java:112)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.apache.maven.surefire.util.ReflectionUtils.invokeMethodWithArray(ReflectionUtils.java:189)
at org.apache.maven.surefire.booter.ProviderFactory$ProviderProxy.invoke(ProviderFactory.java:165)
at org.apache.maven.surefire.booter.ProviderFactory.invokeProvider(ProviderFactory.java:85)
at org.apache.maven.surefire.booter.ForkedBooter.runSuitesInProcess(ForkedBooter.java:115)
at org.apache.maven.surefire.booter.ForkedBooter.main(ForkedBooter.java:75)
Caused by: java.lang.IllegalStateException: Toolkit not initialized
at com.sun.javafx.application.PlatformImpl.runLater(PlatformImpl.java:273)
at com.sun.javafx.application.PlatformImpl.runLater(PlatformImpl.java:268)
at com.sun.javafx.application.PlatformImpl.setPlatformUserAgentStylesheet(PlatformImpl.java:550)
at com.sun.javafx.application.PlatformImpl.setDefaultPlatformUserAgentStylesheet(PlatformImpl.java:512)
at javafx.scene.control.Control.<clinit>(Control.java:87)
... 50 more

Create a class MockApp extends Application and have a static method init(). In that method create a new single thread in which to invoke the JavaFX platform start (basically what you've done already) with an appropriate guard. The guard (a boolean flag) guarantees that the method gets called maximum once. The point is that the thread never terminates, thus allowing you to access the JavaFX platform during the lifetime of all your tests. The catch is you need to add something like:
#BeforeClass
public void init() {
MockApp.init();
}
for each test class where you use JavaFX since you don't know the order in which tests run.
The approach (with minor changes) can be seen in practice here.

NullPointerException while fast updating TextField

I'm working on an app, that searches some files in the directed folder and prints them in TableView<myFile> foundFilesList, that is stored in the Main class. myFile just extends File a bit. The searching is done using service in background thread, that puts found data to ObservableList<myFile> filesOfUser.
I want to display current amount of find files in TextField foundFilesAmount in the same view, where TableView with files is located -- ResultsView
To do that, I added a ListChangeListener for foundFilesList to ResultsView controller, that uses method setText to print current size of filesOfUser. It looks like:
Main.filesOfUser.addListener(new ListChangeListener<myFile>() {
#Override
public void onChanged(Change<? extends myFile> c) {
while (c.next()){
if (c.wasAdded())
setCounter(c.getAddedSize());
}
}
});
void setCounter (int number) contains only
int currValue = Integer.valueOf(foundFilesAmount.getText());
foundFilesAmount.setText(String.valueOf(currValue + number));
And now what the problem is. Textfield with current amount of find files is updated very fast, and from one moment it stops doing it. In the console I see lots of repeated NullPointerException's from JavaFX Application Thread. Its' contents:
Exception in thread "JavaFX Application Thread" java.lang.NullPointerException
at com.sun.javafx.text.PrismTextLayout.getRuns(PrismTextLayout.java:236)
at javafx.scene.text.Text.getRuns(Text.java:317)
at javafx.scene.text.Text.updatePGText(Text.java:1465)
at javafx.scene.text.Text.impl_updatePeer(Text.java:1500)
at javafx.scene.Node.impl_syncPeer(Node.java:503)
at javafx.scene.Scene$ScenePulseListener.synchronizeSceneNodes(Scene.java:2290)
at javafx.scene.Scene$ScenePulseListener.pulse(Scene.java:2419)
at com.sun.javafx.tk.Toolkit.lambda$runPulse$30(Toolkit.java:355)
at java.security.AccessController.doPrivileged(Native Method)
at com.sun.javafx.tk.Toolkit.runPulse(Toolkit.java:354)
at com.sun.javafx.tk.Toolkit.firePulse(Toolkit.java:381)
at com.sun.javafx.tk.quantum.QuantumToolkit.pulse(QuantumToolkit.java:510)
at com.sun.javafx.tk.quantum.QuantumToolkit.pulse(QuantumToolkit.java:490)
at com.sun.javafx.tk.quantum.QuantumToolkit.lambda$runToolkit$404(QuantumToolkit.java:319)
at com.sun.glass.ui.InvokeLaterDispatcher$Future.run(InvokeLaterDispatcher.java:95)
at com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
at com.sun.glass.ui.win.WinApplication.lambda$null$148(WinApplication.java:191)
at java.lang.Thread.run(Thread.java:745)
I tried to set sort of delay before using setText, like updating value in foundFilesAmount only after 5'th, 10'th, 15'th update, etc. But if the search works longer, exceptions are still thrown.
Is there a correct method to show current amount of found files, that contains real amount and doesn't cause so much exceptions?
Thanks in advance.

The correct way is not doing the updates of the UI on a thread other than the application thread. This can otherwise lead to issues with rendering/layouting.
You could use a Task to do the updates to the updates however:
Task<ObservableList<myFile>> task = new Task<
Task<ObservableList<myFile>>() {
#Override
protected ObservableList<myFile> call() throws Exception {
ObservableList<myFile> files = FXCollections.observableArrayList();
while (...) {
...
files.add(...);
updateMessage(Integer.toString(files.size()));
...
}
return files;
}
};
task.setOnSucceeded(evt -> tableView.setItems(task.getValue()));
Thread t = new Thread(task);
textField.textProperty().bind(task.messageProperty());
t.setDaemon(true);
t.start();

try something like this:
Platform.runLater(new Runnable() {
#Override
public void run() {
// update your JavaFX controls here
}
});

ConcurrentModificationException but not removing anything from ArrayList

So I'm making a game and every 5 seconds there must spawn an enemy, know when I run my application it throws an exception 'ConcurrentModificationException'.
This is a part of my code:
private void tick() {
exec.scheduleAtFixedRate(new Runnable() {
#Override
public void run() {
enemyY = enemyYRand.nextInt(6);
enemy.add(new Enemy(enemyY, 10, enemyImg));
}
}, 0, 5, TimeUnit.SECONDS);
if (player.y > getHeight() - playerImg.getHeight(null)) {
player.setY(-10);
}
if (player.y < 0) {
player.setY(+10);
}
}
public void paintComponent(Graphics g) {
super.paintComponent(g);
for(Enemy enemys : enemy) {
enemys.render(g);
}
player.render(g);
}
First the tick method get's called then paintComponent method.
This is the output:
Exception in thread "AWT-EventQueue-0" java.util.ConcurrentModificationException
at java.util.ArrayList$Itr.checkForComodification(ArrayList.java:901)
at java.util.ArrayList$Itr.next(ArrayList.java:851)
at _47b3n.spaceinvaders.framework.Main.paintComponent(Main.java:141)
at javax.swing.JComponent.paint(JComponent.java:1053)
at javax.swing.JComponent.paintToOffscreen(JComponent.java:5223)
at javax.swing.BufferStrategyPaintManager.paint(BufferStrategyPaintManager.java:290)
at javax.swing.RepaintManager.paint(RepaintManager.java:1265)
at javax.swing.JComponent._paintImmediately(JComponent.java:5171)
at javax.swing.JComponent.paintImmediately(JComponent.java:4982)
at javax.swing.RepaintManager$4.run(RepaintManager.java:824)
at javax.swing.RepaintManager$4.run(RepaintManager.java:807)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:75)
at javax.swing.RepaintManager.paintDirtyRegions(RepaintManager.java:807)
at javax.swing.RepaintManager.paintDirtyRegions(RepaintManager.java:782)
at javax.swing.RepaintManager.prePaintDirtyRegions(RepaintManager.java:731)
at javax.swing.RepaintManager.access$1300(RepaintManager.java:64)
at javax.swing.RepaintManager$ProcessingRunnable.run(RepaintManager.java:1720)
at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:311)
at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:744)
at java.awt.EventQueue.access$400(EventQueue.java:97)
at java.awt.EventQueue$3.run(EventQueue.java:697)
at java.awt.EventQueue$3.run(EventQueue.java:691)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:75)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:714)
at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:201)
at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:116)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:105)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:93)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:82)

It appears that you have 2 threads each operating on an ArrayList at the same time.
One of them is in the event dispatch thread, where paintComponent is called. You are using an enhanced for loop, which uses an Iterator internally. This iterator is what is throwing the ConcurrentModificationException.
You are modifying the ArrayList in the tick method, in some other thread, when you call enemy.add(new Enemy(enemyY, 10, enemyImg));.
The Iterator noticed that the ArrayList was modified and threw the exception. When you are displaying the enemies, it is necessary to have a consistent view of your ArrayList.
Synchronize access to this ArrayList on some object (maybe even enemy itself) by enclosing read and write operations on this ArrayList in synchronized blocks. That means that only one of these blocks can be executing at the same time.
synchronized (enemy) {
enemy.add(new Enemy(enemyY, 10, enemyImg));
}
and
synchronized (enemy) {
for(Enemy enemys : enemy) {
enemys.render(g);
}
}

Java Timer synchronize with GUI

I'm trying to do an incremental display of a Component because it takes too much time to make all the calculations. So i don't want to freeze the graphic interface i'd like to display my image ( a fractal ) every 2.3 seconds. The function which calculate all the points is compute. Before i want to make the incremental display this method was calculating all points. Now it only calculates 10000 points.
class FlameBuilderPreviewComponent:
Timer timer1=new Timer(1000,new ActionListener(){
#Override
public void actionPerformed(ActionEvent e) {
// TODO Auto-generated method stub
time=time+10000;
fa= builder.build().compute(density,frame,getWidth(),getHeight(),accumulator);
}
});
timer1.start();
for (int z = 0; z <fa.height(); z++) {
for (int j = 0; j < fa.width(); j++) {
image.setRGB(j,z,fa.color(palette, background, j, fa.height()-1-z).asPackedRGB());
}
}
g0.drawImage(image,0,0,null);
if (time>density*getWidth()*getHeight()){
timer1.stop();
}
Then the other part of the program is the GUI interface, i put another timer this one is responsible of repainting the image.
class FlameMakerGUI :
fBPC=new FlameBuilderPreviewComponent(builder, background, palette, r1, density);
Timer timer = new Timer(2500,new ActionListener(){
public void actionPerformed(ActionEvent e) {
fBPC.repaint();
System.out.println("titi");
}
});
timer.start();
fractale.add(fBPC,BorderLayout.CENTER);
Then this is the error that the program show each time timer is executed:
Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
at ch.epfl.flamemaker.gui.FlameBuilderPreviewComponent.paintComponent(FlameBuilderPreviewComponent.java:82)
at javax.swing.JComponent.paint(JComponent.java:1054)
at javax.swing.JComponent.paintChildren(JComponent.java:887)
at javax.swing.JComponent.paint(JComponent.java:1063)
at javax.swing.JComponent.paintToOffscreen(JComponent.java:5221)
at javax.swing.RepaintManager$PaintManager.paintDoubleBuffered(RepaintManager.java:1512)
at javax.swing.RepaintManager$PaintManager.paint(RepaintManager.java:1443)
at javax.swing.RepaintManager.paint(RepaintManager.java:1236)
at javax.swing.JComponent._paintImmediately(JComponent.java:5169)
at javax.swing.JComponent.paintImmediately(JComponent.java:4980)
at javax.swing.RepaintManager$3.run(RepaintManager.java:796)
at javax.swing.RepaintManager$3.run(RepaintManager.java:784)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
at javax.swing.RepaintManager.paintDirtyRegions(RepaintManager.java:784)
at javax.swing.RepaintManager.paintDirtyRegions(RepaintManager.java:757)
at javax.swing.RepaintManager.prePaintDirtyRegions(RepaintManager.java:706)
at javax.swing.RepaintManager.access$1000(RepaintManager.java:62)
at javax.swing.RepaintManager$ProcessingRunnable.run(RepaintManager.java:1651)
at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:251)
at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:727)
at java.awt.EventQueue.access$200(EventQueue.java:103)
at java.awt.EventQueue$3.run(EventQueue.java:688)
at java.awt.EventQueue$3.run(EventQueue.java:686)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:697)
at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:242)
at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:161)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:150)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:146)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:138)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:91)
Thank you for helping

You are creating a action listener every second, that doesn't make any sense. You obviously do not understand how event listeners work or how the Timer class works.
Also, tasks on the EDT (event dispatch thread) must finish quickly; if they don't, unhandled events back up and the user interface becomes unresponsive
You need to use Swing Worker in order to archive proper concurrency.
From the Oracle website:
Swing consists of three kinds of threads:
Initial threads, the threads that execute initial application code.
The event dispatch thread, where all event-handling code is executed. Most code that interacts with the Swing framework must also
execute on this thread.
Worker threads, also known as background threads, where time-consuming background tasks are executed.

Using ControlP5 with processing in eclipse results in IllegalArgumentException on keypress

I have a Processing project making use of the ControlP5 library running within eclipse in which, upon any keypress on the keyboard, crashes with an IllegalArgumentException:
Exception in thread "Animation Thread" java.lang.IllegalArgumentException: argument type mismatch
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at processing.core.PApplet$RegisteredMethods.handle(PApplet.java:1076)
at processing.core.PApplet.handleKeyEvent(PApplet.java:2848)
at processing.core.PApplet.dequeueKeyEvents(PApplet.java:2793)
at processing.core.PApplet.handleDraw(PApplet.java:2132)
at processing.core.PGraphicsJava2D.requestDraw(PGraphicsJava2D.java:197)
at processing.core.PApplet.run(PApplet.java:1998)
at java.lang.Thread.run(Unknown Source)
The program (running in an applet) runs perfectly fine with mouse dragging, sliders, etc, until a key is pressed. It seems like there is some sort of unknown keylistener waiting for input and using it incorrectly? It is difficult to tell because the exception refers to java code which is unrelated to the processing code which I wrote.
Even if I have a program which only defines a ControlP5 object, the program encounters the same error:
import processing.core.*;
import controlP5.*;
public class Lensing extends PApplet {
ControlP5 controlP5;
public Lensing() {
}
public void setup() {
controlP5 = new ControlP5(this);
}
public void draw() {
}
public static void main(String args[]) {
PApplet.main(new String[] { "--present", "edu.umd.astro.Lensing" });
}
}
Comment out the single controlP5 definition, and no exception occurs.

Turns out it was an issue related to using the 2.0b1 core jar file, and can be remedied by updating to 2.0b3 from http://processing.org/download/
credit to reply on here https://forum.processing.org/topic/using-controlp5-with-processing-in-eclipse-results-in-illegalargumentexception-on-keypress