如何使用 Javafx 显示我在选项卡窗格中选择的文件的内容？

Question

This code will use filechooser to select a file that is anything that ends with.cvs so when i choose the grades.cvs file i need it to display the content within the file within the tab. All it does is once the file is picked it does not display it. I tried to use tab1.setContent this is my first time using tab i see people display messages in tab with label.

import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;[enter image description here][1]
import java.util.Scanner;

import javafx.event.ActionEvent;
import javafx.fxml.FXML;
import javafx.scene.Group;
import javafx.scene.Scene;
import javafx.scene.control.Label;
import javafx.scene.control.Tab;
import javafx.scene.control.TabPane;
import javafx.scene.control.TextArea;
import javafx.scene.text.Font;
import javafx.stage.FileChooser;
import javafx.stage.FileChooser.ExtensionFilter;
import javafx.stage.Stage;

public class Controller {

    @FXML
    private Tab tab1;

    @FXML
    private Tab tab2;


    @FXML
    void openFile(ActionEvent event) {
        FileChooser fc = new FileChooser();
        fc.setTitle("Open Text File");
        fc.setInitialDirectory(new File("."));
        fc.getExtensionFilters().addAll(new ExtensionFilter("Text Files", "*.csv"));
        File selectedFile = fc.showOpenDialog(null);


        TextArea content = new TextArea();
        content.setEditable(false);



        if (selectedFile == null)
            content.setText("No file chosen.");
        else
        {
            Scanner scan = new Scanner(selectedFile);

            String info = "";
            while (scan.hasNext())
                info += scan.nextLine() + "\n";

            content.setText(info);
        }
        tab1.setContent(content);
    }

    @FXML
    void openWindow(ActionEvent event) {
        Stage subWindow = new Stage();
        Label lbl1 = new Label("This is about the developer of app");

        Group grp = new Group(lbl1);
        Scene sn = new Scene(grp,300,300);
        subWindow.setScene(sn);
        subWindow.show();
    }

}

Answer 1

Here is some code we wrote in 2015 to test using a CSV file as a database
It is backed by a Model Class so we are using Model View Controller
the first code post is how we save the data then how we fetch the data

    @FXML
private void onSave(ActionEvent e) throws IOException {

    // TableData = FXCollections.observableArrayList();
    // Hold data for the table

    if (txfFName.getText().isEmpty() || txfLName.getText().isEmpty()|| txfPNum.getText().isEmpty() || txfEMail.getText().isEmpty()) {
        Alert alert = new Alert(AlertType.WARNING);
        alert.initStyle(StageStyle.UTILITY);
        alert.setTitle("Information");
        alert.setHeaderText("");
        alert.setContentText("Data Entry NOT Complete\n"
        + "\nENTER New Data in All Fields and Alt + S to SAVE");
        alert.showAndWait();

    if (txfFName.getText().isEmpty()) {
        txfFName.requestFocus();
    return;
    }
    if (txfLName.getText().isEmpty()) {
        txfLName.requestFocus();
    return;
    }
    if (txfPNum.getText().isEmpty()) {
        txfPNum.requestFocus();
    return;
    }
    if (txfEMail.getText().isEmpty()) {
        txfEMail.requestFocus();
    return;
    }
    return;
    }

    if (txfFName.getText().length() > 15) {
        Alert alert = new Alert(AlertType.WARNING);
        alert.initStyle(StageStyle.UTILITY);
        alert.setTitle("Information");
        alert.setHeaderText("");
        alert.setContentText("First Name Max Length is 15 Characters");
        alert.showAndWait();
        txfFName.requestFocus();
    return;
    }

    if (txfLName.getText().length() > 16) {
        Alert alert = new Alert(AlertType.WARNING);
        alert.initStyle(StageStyle.UTILITY);
        alert.setTitle("Information");
        alert.setHeaderText("");
        alert.setContentText("Last Name Max Length is 16 Characters");
        alert.showAndWait();
        txfLName.requestFocus();
    return;
    }

    if (txfPNum.getText().length() > 12) {
        Alert alert = new Alert(AlertType.WARNING);
        alert.initStyle(StageStyle.UTILITY);
        alert.setTitle("Information");
        alert.setHeaderText("");
        alert.setContentText("Phone Number Max Length is 12 Characters");
        alert.showAndWait();
        txfPNum.requestFocus();
    return;
    }

    if (txfEMail.getText().length() > 30) {
        Alert alert = new Alert(AlertType.WARNING);
        alert.initStyle(StageStyle.UTILITY);
        alert.setTitle("Information");
        alert.setHeaderText("");
        alert.setContentText("E-Mail Max Length is 30 Characters");
        alert.showAndWait();
        txfEMail.requestFocus();
    return;
    }

    String fname = txfFName.getText().trim();
    String lname = txfLName.getText().trim();
    String pnum = txfPNum.getText().trim();
    String email = txfEMail.getText().trim();

    String data = (fname + "," + lname + "," + pnum + "," + email + "," + '\r');

    File dirPath = new File("C:/A_CSV");
    dirPath.mkdirs();// Make the directory

    File file = new File(dirPath, "People.csv");
    if (!file.exists()) {
            file.createNewFile();// Create an empty text file
    }

Her is the fetch data code

    @FXML
// Load CSV Data
private void onLoad(ActionEvent e) throws IOException {

// TableData = FXCollections.observableArrayList();//Hold data for the table

    File fileInfo = new File("C:/A_CSV/People.csv");
    if (fileInfo.length() == 0) {
        Alert alert = new Alert(AlertType.WARNING);
        alert.initStyle(StageStyle.UTILITY);
        alert.setTitle("Information");
        alert.setHeaderText("");
        alert.setContentText("No Data in File at " + fileInfo + "\n"
        + "\nEnter Data and Save");
        alert.showAndWait();
    return;
    }

    fc.setTitle("Load Contacts Info");
    fc.setInitialDirectory(new File("C:/"));
    fc.setInitialDirectory(new File("C:/A_CSV"));
    fc.setInitialFileName("People.csv");
    File file = fc.showOpenDialog(null);
    if (file == null) {
            return;
    }

    String correctFile = file.getName();
    if (!(correctFile.matches("People.csv"))) {
        Alert alert = new Alert(AlertType.ERROR);
        alert.initStyle(StageStyle.UTILITY);
        alert.setTitle("Information");
        alert.setHeaderText("");
        alert.setContentText("The File at " + file + "\n\n"
        + "is NOT accociated with this application\n\n"
        + "Select the File at " + fileInfo);
        alert.showAndWait();
    return;
    }

    unAdd();
    table.getItems().clear();// Clears the table
    onShowTableData();

}

Here is the Model Class Just a bunch of Getters and Setters

public class Person {
// This belongs to CSV Controller
// ===============================
private final StringProperty firstName = new SimpleStringProperty(this,"firstName", null);
private final StringProperty lastName = new SimpleStringProperty(this,"lastName", null);
private final StringProperty phoneNumber = new SimpleStringProperty(this,"phoneNumber", null);
private final StringProperty emailAddress = new SimpleStringProperty(this,"emailAddress", null);

public Person() {
    this(null, null, null, null);
}

public Person(String firstName, String lastName, String phoneNumber,String emailAddress) {
    this.firstName.set(firstName);
    this.lastName.set(lastName);
    this.phoneNumber.set(phoneNumber);
    this.emailAddress.set(emailAddress);
}

/* firstName Property */
public final String getFirstName() {// 1
    return firstName.get();
}

public final void setFirstName(String firstName) {// 1
    firstNameProperty().set(firstName);
}

public final StringProperty firstNameProperty() {// 1
    return firstName;
}

public final String getLastName() {// 2
    return lastName.get();
}

public final void setLastName(String lastName) {// 2
    lastNameProperty().set(lastName);
}

public final StringProperty lastNameProperty() {// 2
    return lastName;
}

public final String getPhoneNumber() {// 3
    return phoneNumber.get();
}

public final void setPhoneNumber(String phoneNumber) {// 3
    phoneNumberProperty().set(phoneNumber);
}

public final StringProperty phoneNumberProperty() {// 3
    return phoneNumber;
}

public final String getEmailAddress() {
    return emailAddress.get();
}

public final void setEmailAddress(String emailAddress) {
    emailAddressProperty().set(emailAddress);
}

public final StringProperty emailAddressProperty() {
    return emailAddress;
}

If you want the whole project let me know and I will zip it up and put on GitHub