JavaFX Image Error

Question

I am trying to make a simple program that randomly picks a number between 1 and 52 and draws a card based on the number. The card will be displayed by JavaFX. However, whenever I run anything I get a whole slew of errors.

So far, my main thought is that my project cannot find the images. I have created a folder called "resources" and they are stored there, as well as referencing them directly in a folder on the desktop. Still no luck.

Here is the code:

(Imports removed for brevity)...

 public class Draw5 extends Application {
  @Override // Override the start method in the Application class
  public void start(Stage primaryStage) throws IOException {
    // Create a list of card numbers
    ArrayList<Integer> cards = getCards();
    // Create a HBox pane
    HBox pane = new HBox(5);
    pane.setPadding(new Insets(5, 5, 5, 5));

    // Add nodes to pane
    for (int i = 0; i < 5; i++) {

        pane.getChildren().add(new ImageView(new Image("C:\\Users\\Matthew\\Desktop\\card\\" +
                cards.get(i) + ".png")));

    }

    // Create a scene and place it in the stage
    Scene scene = new Scene(pane);
    primaryStage.setTitle("Exercise_14_03"); // Set the stage title
    primaryStage.setScene(scene); // Place the scene in the stage
    primaryStage.show(); // Display the stage
}

/** Returns a list with numbers 1-52 stored in random order */
private ArrayList<Integer> getCards() {
    ArrayList<Integer> cards = new ArrayList<>();
    for (int i = 0; i < 52; i++) {
        cards.add(i + 1);
    }
    java.util.Collections.shuffle(cards);
    return cards;
}


public static void main(String[] args) {
    Application.launch(args);
}

}

Like I said, I get the funny feeling that the project cannot find the 52 .png images of the cards. If anyone has any suggestions please let me know.

For the record, the cards are randomly chosen, hence why the "cards.get(i) + ".png" "

Here are the errors that I am getting upon launch:

Exception in Application start method
Exception in thread "main" java.lang.reflect.InvocationTargetException
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.base/java.lang.reflect.Method.invoke(Unknown Source)
at java.base/sun.launcher.LauncherHelper$FXHelper.main(Unknown Source)


Caused by: java.lang.RuntimeException: Exception in Application start method
 at javafx.graphics/com.sun.javafx.application.LauncherImpl.launchApplication1(Unknown Source)
 at javafx.graphics/com.sun.javafx.application.LauncherImpl.lambda$launchApplication$2(Unknown Source)
 at java.base/java.lang.Thread.run(Unknown Source)



Caused by: java.lang.IllegalArgumentException: Invalid URL: unknown protocol: c
at javafx.graphics/javafx.scene.image.Image.validateUrl(Unknown Source)
at javafx.graphics/javafx.scene.image.Image.<init>(Unknown Source)
at thibodeau14.Draw5.start(Draw5.java:31)
at javafx.graphics/com.sun.javafx.application.LauncherImpl.lambda$launchApplication1$9(Unknown Source)
at javafx.graphics/com.sun.javafx.application.PlatformImpl.lambda$runAndWait$11(Unknown Source)
at javafx.graphics/com.sun.javafx.application.PlatformImpl.lambda$runLater$9(Unknown Source)
at java.base/java.security.AccessController.doPrivileged(Native Method)
at javafx.graphics/com.sun.javafx.application.PlatformImpl.lambda$runLater$10(Unknown Source)
at javafx.graphics/com.sun.glass.ui.InvokeLaterDispatcher$Future.run(Unknown Source)
at javafx.graphics/com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
at javafx.graphics/com.sun.glass.ui.win.WinApplication.lambda$runLoop$3(Unknown Source)
... 1 more
Caused by: java.net.MalformedURLException: unknown protocol: c
at java.base/java.net.URL.<init>(Unknown Source)
at java.base/java.net.URL.<init>(Unknown Source)
at java.base/java.net.URL.<init>(Unknown Source)
... 12 more

SteelToe · Accepted Answer · 2018-03-23T04:22:07.143

1

The Image class constructor requires a string representing a URL, when representing a URL with a string that is for a file add "file///" to the URL.

So this:

pane.getChildren().add(new ImageView(new Image("C:\\Users\\Matthew\\Desktop\\card\\" +
               cards.get(i) + ".png")));

Becomes:

pane.getChildren().add(new ImageView(new 
Image("file:\\\C:\\Users\\Matthew\\Desktop\\card\\" +
                cards.get(i) + ".png")));`

edited Mar 23 '18 at 04:22

answered Mar 23 '18 at 03:57

SteelToe

2,477
1
17
28

2

The string in your ecode snippet does not properly escape the first 3 backslashes. Furthermore I'm supprised JavaFX can deal with a URL using backslashes instead of slashes. Moreover it's not safe to convert arbitrary file paths to URL this way: If e.g. some part of a filename contains a space this would likely fail. Better use `new File(filePath).toURI().toURL().toExternalForm()`... – fabian Mar 23 '18 at 07:48

JavaFX Image Error

1 Answers1