Every time I try to execute the code to produce the application I get this error. Unsure of what the problem is

Error that occurred when I ran the code

Exception in thread "main" 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 sun.launcher.LauncherHelper$FXHelper.main(LauncherHelper.java:873)  Caused by: java.lang.RuntimeException: Unable to construct Application instance: class sample.Main      at com.sun.javafx.application.LauncherImpl.launchApplication1(LauncherImpl.java:907)      at com.sun.javafx.application.LauncherImpl.lambda$launchApplication$1(LauncherImpl.java:182)      at java.lang.Thread.run(Thread.java:748)  Caused by: java.lang.NoSuchMethodException: sample.Main.<init>()      at java.lang.Class.getConstructor0(Class.java:3082)      at java.lang.Class.getConstructor(Class.java:1825)      at com.sun.javafx.application.LauncherImpl.lambda$launchApplication1$7(LauncherImpl.java:818)      at com.sun.javafx.application.PlatformImpl.lambda$runAndWait$7(PlatformImpl.java:326)      at com.sun.javafx.application.PlatformImpl.lambda$null$5(PlatformImpl.java:295)      at java.security.AccessController.doPrivileged(Native Method)      at com.sun.javafx.application.PlatformImpl.lambda$runLater$6(PlatformImpl.java:294)      at com.sun.glass.ui.InvokeLaterDispatcher$Future.run(InvokeLaterDispatcher.java:95)      at com.sun.glass.ui.win.WinApplication._runLoop(Native Method)      at com.sun.glass.ui.win.WinApplication.lambda$null$4(WinApplication.java:185)      ... 1 more  

XML file that contains the buttons and the label etc.

<?xml version="1.0" encoding="UTF-8"?>    <?import javafx.scene.control.Button?>  <?import javafx.scene.control.Label?>  <?import javafx.scene.control.Menu?>  <?import javafx.scene.control.MenuBar?>  <?import javafx.scene.control.MenuItem?>  <?import javafx.scene.layout.AnchorPane?>      <AnchorPane maxHeight="-Infinity" maxWidth="-Infinity" minHeight="-Infinity" minWidth="-Infinity" prefHeight="450.0" prefWidth="615.0" xmlns="http://javafx.com/javafx/15.0.1" xmlns:fx="http://javafx.com/fxml/1">     <children>        <MenuBar layoutY="2.0" AnchorPane.leftAnchor="0.0" AnchorPane.rightAnchor="0.0" AnchorPane.topAnchor="0.0">          <menus>            <Menu disable="true" mnemonicParsing="false" text="File">              <items>                <MenuItem mnemonicParsing="false" text="Close" />              </items>            </Menu>            <Menu disable="true" mnemonicParsing="false" text="Edit">              <items>                <MenuItem mnemonicParsing="false" text="Delete" />              </items>            </Menu>            <Menu disable="true" mnemonicParsing="false" text="Help">              <items>                <MenuItem mnemonicParsing="false" text="About" />              </items>            </Menu>          </menus>        </MenuBar>        <Button layoutX="190.0" layoutY="173.0" mnemonicParsing="false" onAction="#headmaterLogin" prefHeight="52.0" prefWidth="195.0" text="Headmaster" />        <Button layoutX="190.0" layoutY="102.0" mnemonicParsing="false" onAction="#adminLogin" prefHeight="52.0" prefWidth="195.0" text="Admin" />        <Button layoutX="190.0" layoutY="305.0" mnemonicParsing="false" onAction="#financedepartmentLogin" prefHeight="52.0" prefWidth="195.0" text="Finance department" />        <Button layoutX="190.0" layoutY="236.0" mnemonicParsing="false" onAction="#headdepartmentLogin" prefHeight="52.0" prefWidth="195.0" text="Head of department" />        <Label layoutX="216.0" layoutY="52.0" prefHeight="35.0" prefWidth="143.0" text="Select an option to Log in" />     </children>  </AnchorPane>  

Main function. That creates the screen. As this function is called when the code is executed.

package sample;    import javafx.application.Application;  import javafx.fxml.FXMLLoader;  import javafx.scene.Parent;  import javafx.scene.Scene;  import javafx.stage.Stage;    class Main extends Application {        @Override      public void start(Stage primaryStage) throws Exception{          Parent root = FXMLLoader.load(getClass().getResource("mainMenu.fxml"));          primaryStage.setTitle("Main menu");          primaryStage.setScene(new Scene(root, 300, 275));          primaryStage.show();      }        }  

Controllers, these are the methods that would link to the button events. Resulting in something occurring when the buttons are clicked.

package sample;    import java.net.URL;  import java.util.ResourceBundle;  import javafx.event.ActionEvent;  import javafx.fxml.FXML;    public class mainMenuController {        @FXML      private ResourceBundle resources;        @FXML      private URL location;        @FXML      protected void adminLogin(ActionEvent event) {          int count = 0;          System.out.print(count);      }        @FXML      protected void financedepartmentLogin(ActionEvent event) {        }        @FXML      protected void headdepartmentLogin(ActionEvent event) {        }        @FXML      protected void headmasterLogin(ActionEvent event) {        }        @FXML      void initialize() {        }  }  

https://stackoverflow.com/questions/66020151/every-time-i-try-to-execute-the-code-to-produce-the-application-i-get-this-error February 03, 2021 at 09:49AM