java - 奇怪的 Java FXML NumberFormatException？

Question

每当我执行某个操作时，我都会得到这个

Button[id=gButton, styleClass=button]'Guess'
gField content: 44
Exception in thread "JavaFX Application Thread" java.lang.RuntimeException: java.lang.reflect.InvocationTargetException
    at javafx.fxml.FXMLLoader$MethodHandler.invoke(FXMLLoader.java:1762)
    at javafx.fxml.FXMLLoader$ControllerMethodEventHandler.handle(FXMLLoader.java:1645)
    at com.sun.javafx.event.CompositeEventHandler.dispatchBubblingEvent(CompositeEventHandler.java:86)
    at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:238)
    at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:191)
    at com.sun.javafx.event.CompositeEventDispatcher.dispatchBubblingEvent(CompositeEventDispatcher.java:59)
    at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:58)
    at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
    at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
    at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
    at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
    at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
    at com.sun.javafx.event.EventUtil.fireEventImpl(EventUtil.java:74)
    at com.sun.javafx.event.EventUtil.fireEvent(EventUtil.java:49)
    at javafx.event.Event.fireEvent(Event.java:198)
    at javafx.scene.Node.fireEvent(Node.java:8216)
    at javafx.scene.control.Button.fire(Button.java:185)
    at com.sun.javafx.scene.control.behavior.ButtonBehavior.mouseReleased(ButtonBehavior.java:182)
    at com.sun.javafx.scene.control.skin.BehaviorSkinBase$1.handle(BehaviorSkinBase.java:96)
    at com.sun.javafx.scene.control.skin.BehaviorSkinBase$1.handle(BehaviorSkinBase.java:89)
    at com.sun.javafx.event.CompositeEventHandler$NormalEventHandlerRecord.handleBubblingEvent(CompositeEventHandler.java:218)
    at com.sun.javafx.event.CompositeEventHandler.dispatchBubblingEvent(CompositeEventHandler.java:80)
    at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:238)
    at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:191)
    at com.sun.javafx.event.CompositeEventDispatcher.dispatchBubblingEvent(CompositeEventDispatcher.java:59)
    at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:58)
    at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
    at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
    at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
    at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
    at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
    at com.sun.javafx.event.EventUtil.fireEventImpl(EventUtil.java:74)
    at com.sun.javafx.event.EventUtil.fireEvent(EventUtil.java:54)
    at javafx.event.Event.fireEvent(Event.java:198)
    at javafx.scene.Scene$MouseHandler.process(Scene.java:3724)
    at javafx.scene.Scene$MouseHandler.access$1500(Scene.java:3452)
    at javafx.scene.Scene.impl_processMouseEvent(Scene.java:1728)
    at javafx.scene.Scene$ScenePeerListener.mouseEvent(Scene.java:2461)
    at com.sun.javafx.tk.quantum.GlassViewEventHandler$MouseEventNotification.run(GlassViewEventHandler.java:348)
    at com.sun.javafx.tk.quantum.GlassViewEventHandler$MouseEventNotification.run(GlassViewEventHandler.java:273)
    at java.security.AccessController.doPrivileged(Native Method)
    at com.sun.javafx.tk.quantum.GlassViewEventHandler.handleMouseEvent(GlassViewEventHandler.java:382)
    at com.sun.glass.ui.View.handleMouseEvent(View.java:553)
    at com.sun.glass.ui.View.notifyMouse(View.java:925)
    at com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
    at com.sun.glass.ui.win.WinApplication.lambda$null$141(WinApplication.java:102)
    at com.sun.glass.ui.win.WinApplication$$Lambda$37/728890494.run(Unknown Source)
    at java.lang.Thread.run(Thread.java:745)
Caused by: java.lang.reflect.InvocationTargetException
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:483)
    at sun.reflect.misc.Trampoline.invoke(MethodUtil.java:71)
    at sun.reflect.GeneratedMethodAccessor1.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:483)
    at sun.reflect.misc.MethodUtil.invoke(MethodUtil.java:275)
    at javafx.fxml.FXMLLoader$MethodHandler.invoke(FXMLLoader.java:1757)
    ... 47 more
Caused by: java.lang.NumberFormatException: For input string: ""
    at java.lang.NumberFormatException.forInputString(NumberFormatException.java:65)
    at java.lang.Integer.parseInt(Integer.java:592)
    at java.lang.Integer.parseInt(Integer.java:615)
    at javafxapplication.FXMLDocumentController.handleButtonAction(FXMLDocumentController.java:44)
    ... 57 more

注意输入字符串的 NumberFormatException:"" - 您可以在第 2 行看到我的输入，gField content: 44这是我的 FXMLDocumentController.java:

private Label gLabel;
@FXML
private Button rButton;
@FXML
private Button gButton;
@FXML
private SubScene colorBar;
@FXML
private TextField gField;

@FXML
private void handleButtonAction(ActionEvent event) {
    Object source = event.getSource();
    String guess = gField.getText();
    System.out.println("You clicked me!");
    System.out.println(source);
    if (source == gButton || source == gButton) {
        if (Integer.parseInt(guess) > JavaFXApplication.nToGuess) {
            JavaFXApplication.nTries++;
            gLabel.setText("Too High!");

        } else if (Integer.parseInt(guess) < JavaFXApplication.nToGuess) {
            JavaFXApplication.nTries++;
            gLabel.setText("Too Low!");

        } else if (Integer.parseInt(guess) == JavaFXApplication.nToGuess) {
            if (JavaFXApplication.nTries > 1) {
                gLabel.setText("Took you " + JavaFXApplication.nTries + " tries. Restarted.");
                System.out.println("Took you " + JavaFXApplication.nTries + " tries. Restarted.");
            } else if (JavaFXApplication.nTries == 0) {
                gLabel.setText("You are a hacker.");
                System.out.println("You are a hacker.");
            } else if (JavaFXApplication.nTries == 1) {
                gLabel.setText("It's taken you only 1 try.");
                System.out.println("It's taken you only 1 try.");
            }
            JavaFXApplication.nTries = 0;
            JavaFXApplication.rand = new Random();
            JavaFXApplication.nToGuess = JavaFXApplication.rand.nextInt(100);
            System.out.println(JavaFXApplication.nToGuess);
        }
    } else if (source == rButton) {
        JavaFXApplication.nTries = 0;
        gLabel.setText("Game has been restarted.");
        JavaFXApplication.rand = new Random();
        JavaFXApplication.nToGuess = JavaFXApplication.rand.nextInt(100);
        System.out.println("Game restarted.\n" + JavaFXApplication.nToGuess);
    }
    gField.setText(null);
}

@Override
public void initialize(URL url, ResourceBundle rb) {
    assert gButton != null : "fx:id=\"myButton\" was not injected: check your FXML file 'simple.fxml'.";
    assert rButton != null : "fx:id=\"myButton\" was not injected: check your FXML file 'simple.fxml'.";
    assert colorBar != null : "fx:id=\"myButton\" was not injected: check your FXML file 'simple.fxml'.";
    assert gLabel != null : "fx:id=\"myButton\" was not injected: check your FXML file 'simple.fxml'.";
    assert gField != null : "fx:id=\"myButton\" was not injected: check your FXML file 'simple.fxml'.";


}  

这是我的JavaFXApplication.java:

static int nTries = 0;
static Random rand = new Random();
static int nToGuess = rand.nextInt(100);
@Override
public void start(Stage stage) throws Exception {

    Parent root = FXMLLoader.load(getClass().getResource("FXMLDocument.fxml"));

    Scene scene = new Scene(root);
    stage.setScene(scene);
    stage.show();
}

/**
 * @param args the command line arguments
 */
public static void main(String[] args) {
    launch(args);
}
public static String nTriesTextGetter() {
    return Integer.toString(nTries);
}

我知道在 swing 中您必须使用操作事件监听器和 EventQueue.invokeLater 以便逻辑不会在 EDT 线程中运行，这是我使用 JavaFX 的第一个应用程序。任何解释都会有很大帮助。

Answer 1

你的字符串也包含空值，如果你超过了整数的大小限制，就会出现这种类型的错误。