Handler method not found javafx

Question

I'm having some trouble programming the controller for a fxml file in javafx. Here's my fxml code:

<?xml version="1.0" encoding="UTF-8"?>

<?import javafx.geometry.Insets?>
<?import javafx.scene.control.Button?>
<?import javafx.scene.control.Label?>
<?import javafx.scene.control.PasswordField?>
<?import javafx.scene.control.TextField?>
<?import javafx.scene.layout.ColumnConstraints?>
<?import javafx.scene.layout.GridPane?>
<?import javafx.scene.layout.RowConstraints?>
<?import javafx.scene.text.Font?>

<GridPane maxHeight="-Infinity" maxWidth="-Infinity" minHeight="-Infinity" minWidth="-Infinity" prefHeight="448.0" prefWidth="657.0" style="-fx-background-color: #8B0000;" xmlns="http://javafx.com/javafx/8.0.171" xmlns:fx="http://javafx.com/fxml/1" fx:controller="conecta4.loginController">
  <columnConstraints>
    <ColumnConstraints />
      <ColumnConstraints maxWidth="411.0" minWidth="289.0" prefWidth="397.0" />
      <ColumnConstraints hgrow="SOMETIMES" maxWidth="383.0" minWidth="10.0" prefWidth="260.0" />
  </columnConstraints>
  <rowConstraints>
    <RowConstraints />
      <RowConstraints minHeight="10.0" prefHeight="30.0" vgrow="SOMETIMES" />
  </rowConstraints>
   <children>
      <GridPane prefHeight="522.0" prefWidth="490.0" GridPane.columnIndex="2" GridPane.rowIndex="1">
        <columnConstraints>
          <ColumnConstraints hgrow="SOMETIMES" minWidth="10.0" prefWidth="100.0" />
        </columnConstraints>
        <rowConstraints>
          <RowConstraints minHeight="10.0" prefHeight="30.0" vgrow="SOMETIMES" />
          <RowConstraints minHeight="10.0" prefHeight="30.0" vgrow="SOMETIMES" />
          <RowConstraints minHeight="10.0" prefHeight="30.0" vgrow="SOMETIMES" />
        </rowConstraints>
         <children>
            <GridPane>
              <columnConstraints>
                <ColumnConstraints hgrow="SOMETIMES" minWidth="10.0" prefWidth="100.0" />
              </columnConstraints>
              <rowConstraints>
                <RowConstraints minHeight="10.0" prefHeight="30.0" vgrow="SOMETIMES" />
              </rowConstraints>
               <children>
                  <Label alignment="CENTER" prefHeight="38.0" prefWidth="341.0" text="Iniciar sesión" textFill="WHITE">
                     <font>
                        <Font size="26.0" />
                     </font>
                  </Label>
               </children>
            </GridPane>
            <Button mnemonicParsing="false" onAction="#changeScreenButtonPushed" style="-fx-background-color: #8B0000; -fx-border-color: #8B0000; -fx-text-fill: #00FFFF;" text="Registro" GridPane.halignment="CENTER" GridPane.rowIndex="2" />
            <GridPane GridPane.rowIndex="1">
              <columnConstraints>
                <ColumnConstraints hgrow="SOMETIMES" minWidth="10.0" prefWidth="100.0" />
              </columnConstraints>
              <rowConstraints>
                  <RowConstraints minHeight="10.0" prefHeight="30.0" vgrow="SOMETIMES" />
                <RowConstraints minHeight="10.0" prefHeight="30.0" vgrow="SOMETIMES" />
                <RowConstraints minHeight="10.0" prefHeight="30.0" vgrow="SOMETIMES" />
              </rowConstraints>
               <children>
                  <TextField fx:id="user" promptText="Usuario">
                     <GridPane.margin>
                        <Insets left="10.0" right="20.0" />
                     </GridPane.margin>
                  </TextField>
                  <PasswordField promptText="Contraseña" GridPane.rowIndex="1">
                     <GridPane.margin>
                        <Insets left="10.0" right="20.0" />
                     </GridPane.margin>
                  </PasswordField>
                  <Button mnemonicParsing="false" onAction="#doesPlayerExist" style="-fx-background-color: #8B0000;" text="Continuar" GridPane.halignment="CENTER" GridPane.rowIndex="2" />
               </children>
            </GridPane>
         </children>
      </GridPane>
      <GridPane style="-fx-background-color: #FFFFFF;" GridPane.columnIndex="1" GridPane.rowIndex="1">
        <columnConstraints>
          <ColumnConstraints hgrow="SOMETIMES" minWidth="10.0" prefWidth="100.0" />
        </columnConstraints>
        <rowConstraints>
            <RowConstraints minHeight="10.0" prefHeight="30.0" vgrow="SOMETIMES" />
          <RowConstraints minHeight="10.0" prefHeight="30.0" vgrow="SOMETIMES" />
          <RowConstraints minHeight="10.0" prefHeight="30.0" vgrow="SOMETIMES" />
        </rowConstraints>
         <children>
            <Label fx:id="playerNameLabel" alignment="CENTER" prefHeight="43.0" prefWidth="340.0" style="-fx-text-fill: #8B0000;" text="Conecta 4" textFill="#f8f7f7" GridPane.halignment="CENTER" GridPane.rowIndex="1">
               <font>
                  <Font name="System Bold" size="29.0" />
               </font>
            </Label>
            <Label fx:id="msg" text="Label" GridPane.halignment="CENTER" GridPane.rowIndex="2" />
         </children>
      </GridPane>
   </children>
</GridPane>

And this is my controller:

package conecta4;


import DBAccess.Connect4DAOException;
import java.io.IOException;
import java.net.URL;
import java.util.ResourceBundle;
import java.util.logging.Level;
import java.util.logging.Logger;
import javafx.event.ActionEvent;
import javafx.fxml.FXML;
import javafx.fxml.FXMLLoader;
import javafx.fxml.Initializable;
import javafx.scene.Node;
import javafx.scene.Parent;
import javafx.scene.Scene;
import javafx.scene.control.TextField;
import javafx.scene.control.Label;
import javafx.stage.Stage;
import model.Connect4;

/**
 *
 * @author Javi
 */
public class loginController implements Initializable  {
    
    Connect4 connect4;
    @FXML
    private Label msg;
    @FXML
    private TextField user;
    /*Cuando se llame a este metodo cambia de escena a resgistro*/
      
   @FXML
    public void changeScreenButtonPushed(ActionEvent event) throws IOException{
    
    Parent conecta4Parent = FXMLLoader.load(getClass().getResource("Registro.fxml"));
    Scene conecta4Scene = new Scene(conecta4Parent);
            
            // Esta linea recibe la informacion de Stage
            Stage ventana;
        ventana = (Stage)((Node)event.getSource()).getScene().getWindow();
            ventana.setScene(conecta4Scene);
            ventana.show();
            }

    /**
     *
     * @param event
     */
    
    
    
    @FXML
    public void doesPlayerExist(ActionEvent event, Connect4 objeto, Label msg, TextField user){
       
        if( objeto.exitsNickName(user.toString())==false){
           msg.setText("Este user no está registrado");
            
        }else{
            msg.setText("lsdjfl");
        }
    }
       
   
    
     
    @Override
    public void initialize(URL url, ResourceBundle rb) {
        try {
            connect4 = Connect4.getSingletonConnect4();
        } catch (Connect4DAOException ex) {
            Logger.getLogger(loginController.class.getName()).log(Level.SEVERE, null, ex);
        }
        
       
    }    
    
}

exitsNickname() is correctly imported from a local library. The problem is, it doesn't find doesPlayerExist() button handler, but changeScreenButtonPushed() works just fine, so I think the fxml and the controller are linked correctly. Thanks for your help, I really don't know what to do.

This is the error log:

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$FXHelper.main(LauncherHelper.java:873)
Caused by: java.lang.RuntimeException: Exception in Application start method
    at com.sun.javafx.application.LauncherImpl.launchApplication1(LauncherImpl.java:917)
    at com.sun.javafx.application.LauncherImpl.lambda$launchApplication$1(LauncherImpl.java:182)
    at java.lang.Thread.run(Thread.java:748)
Caused by: javafx.fxml.LoadException: Error resolving onAction='#doesPlayerExist', either the event handler is not in the Namespace or there is an error in the script.
file:xxx

    at javafx.fxml.FXMLLoader.constructLoadException(FXMLLoader.java:2597)
    at javafx.fxml.FXMLLoader.access$100(FXMLLoader.java:103)
    at javafx.fxml.FXMLLoader$Element.processEventHandlerAttributes(FXMLLoader.java:610)
    at javafx.fxml.FXMLLoader$ValueElement.processEndElement(FXMLLoader.java:770)
    at javafx.fxml.FXMLLoader.processEndElement(FXMLLoader.java:2823)
    at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:2532)
    at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:2441)
    at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3214)
    at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3175)
    at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3148)
    at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3124)
    at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3104)
    at javafx.fxml.FXMLLoader.load(FXMLLoader.java:3097)
    at conecta4.Conecta4.start(Conecta4.java:23)
    at com.sun.javafx.application.LauncherImpl.lambda$launchApplication1$8(LauncherImpl.java:863)
    at com.sun.javafx.application.PlatformImpl.lambda$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
Exception running application conecta4.Conecta4
Java Result: 1

AFAIK the signature of a button action must be `void methodName(ActionEvent)` — gkhaos, Apr 20 '21 at 09:24
Does this answer your question? [Javafx button sending arguments to ActionEvent function](https://stackoverflow.com/questions/37902660/javafx-button-sending-arguments-to-actionevent-function) — gkhaos, Apr 20 '21 at 09:25
`msg` is a member variable of `loginController`, which btw should be named `LoginController` by java naming conventions. So why pass it as a parameter at all? Simply use `this.msg` — gkhaos, Apr 20 '21 at 09:47
@gkhaos should I delete my question if it's already answered in another thread? — mariolototo, Apr 20 '21 at 09:51
a note for future questions: please stick to java naming conventions when showing code publicly :) — kleopatra, Apr 20 '21 at 10:27

Handler method not found javafx

0 Answers0