JFXTextField验证错误
问题描述:
这是我的第一个JavaFX程序,我想通过ePass通过eUser和密码接受用户名。当我尝试检查,如果文本框为空,使用验证我得到这个错误:JFXTextField验证错误
Exception in Application start method
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:498)
at com.sun.javafx.application.LauncherImpl.launchApplicationWithArgs(LauncherImpl.java:389)
at com.sun.javafx.application.LauncherImpl.launchApplication(LauncherImpl.java:328)
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 sun.launcher.LauncherHelper$FXHelper.main(LauncherHelper.java:767)
Caused by: java.lang.RuntimeException: Exception in Application start method
at com.sun.javafx.application.LauncherImpl.launchApplication1(LauncherImpl.java:917)
at com.sun.javafx.application.LauncherImpl.lambda$launchApplication$154(LauncherImpl.java:182)
at java.lang.Thread.run(Thread.java:748)
Caused by: javafx.fxml.LoadException:
file:/Users/dylan/NetBeansProjects/JavaFXApplication2/dist/run350595374/JavaFXApplication2.jar!/javafxapplication2/FXMLDocument.fxml
at javafx.fxml.FXMLLoader.constructLoadException(FXMLLoader.java:2601)
at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:2579)
at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:2441)
at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3214)
at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3175)
at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3148)
at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3124)
at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3104)
at javafx.fxml.FXMLLoader.load(FXMLLoader.java:3097)
at javafxapplication2.JavaFXApplication2.start(JavaFXApplication2.java:23)
at com.sun.javafx.application.LauncherImpl.lambda$launchApplication1$161(LauncherImpl.java:863)
at com.sun.javafx.application.PlatformImpl.lambda$runAndWait$174(PlatformImpl.java:326)
at com.sun.javafx.application.PlatformImpl.lambda$null$172(PlatformImpl.java:295)
at java.security.AccessController.doPrivileged(Native Method)
at com.sun.javafx.application.PlatformImpl.lambda$runLater$173(PlatformImpl.java:294)
at com.sun.glass.ui.InvokeLaterDispatcher$Future.run(InvokeLaterDispatcher.java:95)
Caused by: java.lang.NullPointerException
at javafxapplication2.FXMLDocumentController.initialize(FXMLDocumentController.java:48)
at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:2548)
... 14 more
Exception running application javafxapplication2.JavaFXApplication2
Java Result: 1
当我注释掉Controller.java文件eUser.getValidators().add(vali);
和它后面的线,然后没有错误出现。
这是我FXMLDocumentController.java文件:
public class FXMLDocumentController implements Initializable {
@FXML
private JFXTextField eUser;
@FXML
private JFXTextField ePass;
@FXML
private void handleClose(MouseEvent event) {
System.exit(0);
}
@Override
public void initialize(URL url, ResourceBundle rb) {
RequiredFieldValidator vali = new RequiredFieldValidator();
eUser.getValidators().add(vali);
vali.setMessage("No Input Given");
vali.focusedProperty().addListener(new ChangeListener<Boolean>(){
public void changed(ObservableValue<? extends Boolean> observable, Boolean oldValue, Boolean newValue) {
if(!newValue)
{
eUser.validate();
}
}});}}
主要类:
public class JavaFXApplication2 extends Application {
@Override
public void start(Stage stage) throws Exception {
Parent root = FXMLLoader.load(getClass().getResource("FXMLDocument.fxml"));
stage.initStyle(StageStyle.UNDECORATED);
Scene scene = new Scene(root);
stage.setScene(scene);
stage.show();
}
public static void main(String[] args) {
launch(args);
}
}
答
也许这可能是问题。在您的FXML文件中,检查是否将这些ID设置为相关的文本框。这可能是导致NullPointerException的原因。 如果您使用的是SceneBuilder,请单击相关的文本框 - >代码并设置这些文本字段的fx:id。
顺便说一下,你也许可以使用PasswordField,而不是一个TextField :)
作进一步检查,你可以用FXML文件作出贡献,以及(如果我的回答没有解决您的问题)? –
谢谢你帮了大忙。 – Suzume