Question

Add event-handling code for the "Load File” button and its associated TextField so that the user can load the file with the name provided in the text field and display its contents in the text area for editing. If you are using IntelliJ to implement this assignment, place your input text file in the top directory of your IntelliJ project (perhaps you called it "CSE 114"). Use an Alert Dialog to show an informative error message if a problem is encountered while reading the file. The only problem your are likely to encounter is that the user entered an invalid filename. A sample error dialog box is shown below: Homework 8 Extra Credit Assignment Load File garbage Save ile As Error Error File not found. ок To Lower To Upper To Title Case Find: Replace All Replace with: Seconds since last save: 84 #words: TBD #chars: TBD

Answer 1

ErrorDialog_FXMLController.java

import java.io.File;
import java.io.FileNotFoundException;
import java.net.URL;
import java.util.ResourceBundle;
import java.util.Scanner;
import javafx.event.ActionEvent;
import javafx.event.EventHandler;
import javafx.fxml.FXML;
import javafx.fxml.Initializable;
import javafx.scene.control.Alert;
import javafx.scene.control.Alert.AlertType;
import javafx.scene.control.Button;
import javafx.scene.control.TextArea;
import javafx.scene.control.TextField;

public class ErrorDialog_FXMLController implements Initializable {
  
@FXML private Button loadFileButton;
@FXML private TextField fileNameField;
@FXML private TextArea displayArea;
  
@Override
public void initialize(URL url, ResourceBundle rb) {
loadFileButton.setOnAction(new EventHandler<ActionEvent>() {
@Override
public void handle(ActionEvent event) {
loadFileButtonAction();
}
});
}
  
private void loadFileButtonAction()
{
Alert alert = new Alert(AlertType.NONE);
  
if(fileNameField.getText().equals(""))
{
alert.setAlertType(AlertType.ERROR);
alert.setTitle("Field missing alert");
alert.setContentText("Please provide a file name!");
alert.show();
}
else
{
displayArea.setWrapText(true);
displayArea.clear();
String fileName = fileNameField.getText().trim();
File file = new File(fileName);
Scanner fileReader;
try
{
fileReader = new Scanner(file);
while(fileReader.hasNext())
{
if(fileReader.hasNextInt())
{
displayArea.appendText(fileReader.nextInt() + " ");
}
else
{
displayArea.appendText(fileReader.next() + " ");
}
}
alert.setAlertType(AlertType.INFORMATION);
alert.setTitle("Loading success alert");
alert.setContentText("Contents of file \"" + fileName + "\" has been loaded successfully!");
alert.show();
}catch(FileNotFoundException fnfe){
alert.setAlertType(AlertType.ERROR);
alert.setTitle("File not found alert");
alert.setContentText("File not found.");
alert.show();
}
}
}
}

ErrorDialogFXML.fxml

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

<?import javafx.scene.control.Button?>
<?import javafx.scene.control.TextArea?>
<?import javafx.scene.control.TextField?>
<?import javafx.scene.layout.AnchorPane?>

<AnchorPane id="AnchorPane" prefHeight="287.0" prefWidth="498.0" xmlns:fx="http://javafx.com/fxml/1" xmlns="http://javafx.com/javafx/8.0.171" fx:controller="errordialogfile.ErrorDialog_FXMLController">
<children>
<Button fx:id="loadFileButton" layoutX="14.0" layoutY="23.0" mnemonicParsing="false" text="Load File" />
<TextField fx:id="fileNameField" layoutX="90.0" layoutY="23.0" />
<TextArea fx:id="displayArea" layoutX="15.0" layoutY="66.0" prefHeight="200.0" prefWidth="468.0" />
</children>
</AnchorPane>

ErrorDialogFile.java (Main class)

mport javafx.application.Application;
import javafx.fxml.FXMLLoader;
import javafx.scene.Parent;
import javafx.scene.Scene;
import javafx.stage.Stage;

public class ErrorDialogFile extends Application {
  
@Override
public void start(Stage stage) throws Exception {
Parent root = FXMLLoader.load(getClass().getResource("ErrorDialog_FXML.fxml"));
  
Scene scene = new Scene(root);
  
stage.setScene(scene);
stage.setTitle("Homework 8 Extra Credit Assignment");
stage.show();
}

/**
* @param args the command line arguments
*/
public static void main(String[] args) {
launch(args);
}
  
}

**************************************************************** SCREENSHOT ***********************************************************

Load File Field missing alert Error Please provide a file name! OK

Load File words File not found alert Error File not found. OK

Load File words.txt TXT files are useful for storing information in plain text with no special formatting beyond basic fonts and font styles. The file is commonly used for recording notes, direction Loading success alert x ay. If you are sa report, py the popular Message Contents of file "words.txt" has been loaded successfully! OK