I'm working on a JavaFX project. The program works as expected when run through IntelliJ IDEA. However, when I create an artifact and run the jar file, I get the login screen, but as soon as I hit the Login button, the app crashes throwing an error.
I somehow traced the error via the terminal.
My code is as follows.
Main.java :
package application;
import javafx.application.Application;
import javafx.fxml.FXMLLoader;
import javafx.scene.Parent;
import javafx.scene.Scene;
import javafx.stage.Stage;
public class Main extends Application {
@Override
public void start(Stage primaryStage) throws Exception{
Parent root = FXMLLoader.load(getClass().getResource("/FXML/Login.fxml"));
primaryStage.setTitle("Pelican Tours - Login");
primaryStage.setScene(new Scene(root, 311, 429));
primaryStage.show();
primaryStage.setResizable(false);
}
public static void main(String[] args) {
launch(args);
}
}
This invokes the Login.fxml and that in turn calls the LoginController.java :
package Controllers;
import DBConnection.DBHandler;
import application.Main;
import com.jfoenix.controls.JFXButton;
import com.jfoenix.controls.JFXPasswordField;
import com.jfoenix.controls.JFXTextField;
import javafx.fxml.FXML;
import javafx.fxml.FXMLLoader;
import javafx.fxml.Initializable;
import javafx.scene.Parent;
import javafx.scene.Scene;
import javafx.scene.control.Alert;
import javafx.stage.Stage;
import javax.swing.*;
import java.awt.event.ActionEvent;
import java.io.IOException;
import java.net.URL;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ResourceBundle;
public class LoginController implements Initializable {
@FXML
private JFXTextField username;
@FXML
private JFXPasswordField password;
@FXML
private JFXButton login;
private Connection conn;
private DBHandler handler;
private PreparedStatement pst;
@Override
public void initialize(URL location, ResourceBundle resources) {
handler = new DBHandler();
username.setStyle("-fx-text-inner-color:#a0a2ab;");
password.setStyle("-fx-text-inner-color:#a0a2ab;");
}
@FXML
public void logon() {
conn = handler.getConnection();
String query1 = "SELECT * FROM USER WHERE USERNAME=? AND PASSWORD=?";
try{
pst = conn.prepareStatement(query1);
pst.setString(1,username.getText());
pst.setString(2,password.getText());
ResultSet rs = pst.executeQuery();
//Validate resultset
int count = 0;
while(rs.next()){
count++;
}
if(count==1){
System.out.println("Login Successful!");
login.getScene().getWindow().hide();
Stage dashboard = new Stage();
try{
Parent root = FXMLLoader.load(getClass().getResource("/FXML/Dashboard.fxml"));
Scene scene = new Scene(root);
dashboard.setScene(scene);
dashboard.show();
dashboard.setResizable(false);
}catch(Exception e){
System.out.println("Error loading dashboard!");
System.out.println(e);
e.printStackTrace();
}
}else{
Alert alert = new Alert(Alert.AlertType.ERROR);
alert.setHeaderText("Login Failed!");
alert.setContentText("Invalid Username & Password Combination!");
alert.show();
}
}catch(SQLException e){
e.printStackTrace();
}finally{
try{
handler.closeConnection();
}catch(SQLException e){
e.printStackTrace();
}
}
}
}
When the "logon" action is invoked, it is supposed to load the dashboard. However, the application just crashes.
I first printed the exception and then printed its stacktrace. :
Connected!
Login Successful!
Error loading dashboard!
java.lang.NullPointerException: Location is required.
java.lang.NullPointerException: Location is required.
at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3207)
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 Controllers.LoginController.logon(LoginController.java:75)
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.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:498)
at sun.reflect.misc.MethodUtil.invoke(MethodUtil.java:275)
at javafx.fxml.FXMLLoader$MethodHandler.invoke(FXMLLoader.java:1771)
at javafx.fxml.FXMLLoader$ControllerMethodEventHandler.handle(FXMLLoader.java:1657)
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:8413)
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$MouseHandler.process(Scene.java:3757)
at javafx.scene.Scene$MouseHandler.access$1500(Scene.java:3485)
at javafx.scene.Scene.impl_processMouseEvent(Scene.java:1762)
at javafx.scene.Scene$ScenePeerListener.mouseEvent(Scene.java:2494)
at com.sun.javafx.tk.quantum.GlassViewEventHandler$MouseEventNotification.run(GlassViewEventHandler.java:381)
at com.sun.javafx.tk.quantum.GlassViewEventHandler$MouseEventNotification.run(GlassViewEventHandler.java:295)
at java.security.AccessController.doPrivileged(Native Method)
at com.sun.javafx.tk.quantum.GlassViewEventHandler.lambda$handleMouseEvent$354(GlassViewEventHandler.java:417)
at com.sun.javafx.tk.quantum.QuantumToolkit.runWithoutRenderLock(QuantumToolkit.java:389)
at com.sun.javafx.tk.quantum.GlassViewEventHandler.handleMouseEvent(GlassViewEventHandler.java:416)
at com.sun.glass.ui.View.handleMouseEvent(View.java:555)
at com.sun.glass.ui.View.notifyMouse(View.java:937)
To my uderstanding, "java.lang.NullPointerException: Location is required." is caused due to a path error in .getResource().
However, the same path format inside the Main.java class I posted above, works. (That's how I get the login screen).
The folder structure is as follows :
**PLEASE NOTE: ** The program works perfectly in IDE. This error occurs only when running the .jar file.
Thank you in advance!
Yes. Its happening because of the path is wrong. Try to open the jar file using winrar or something like that. Then try to locate your file where you try pass inside getResource. Then try putting that path where inside jar and check running the jar again after compiling
