Invisible GUI? (Java)(Swing)

I'm studying this program, using swing Every time I export the program and run it, I try to set up the GUI JFrame can, but it is not an internal component Thank you in advance ~ Ellis

Code:

import java.awt.Graphics2D;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.Image;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;

import javax.imageio.ImageIO;
import javax.swing.*;

public class Login {
    public static void login_Interface(){

        //Start GUI style//
        try {
            UIManager.setLookAndFeel("com.sun.java.swing.plaf.nimbus.NimbusLookAndFeel");
        } catch (ClassNotFoundException e1) {
            e1.printStackTrace();
        } catch (InstantiationException e1) {
            e1.printStackTrace();
        } catch (illegalaccessexception e1) {
            e1.printStackTrace();
        } catch (UnsupportedLookAndFeelException e1) {
            e1.printStackTrace();
        }
        //      End     //

        JFrame login_Frame = new JFrame("Login - LetsMeet");
        login_Frame.setDefaultCloSEOperation(JFrame.EXIT_ON_CLOSE);
        login_Frame.setSize(750,650);
        login_Frame.setResizable(true);

        JPanel panel_Title = new JPanel();                            //PANEL Title
        panel_Title.setBounds(0,750,150);
        panel_Title.setLayout(null);
        Image logo = null;
        try {
            logo = ImageIO.read(new File("Data/images/logo_letsmeet.png"));
        } catch (IOException e) {
            e.printStackTrace();
        }
        Graphics2D logo_out = ((BufferedImage) logo).createGraphics();
        panel_Title.paint(logo_out);

        JPanel login_Panel = new JPanel();                            //LOGIN Panel
        login_Panel.setBounds(0,150,350,150);
        login_Panel.setLayout(null);
        JTextField username_login = new JTextField("Username");
        username_login.setBounds(100,50,100,25);
        JPasswordField password_login = new JPasswordField();
        password_login.setBounds(200,25);
        JButton login_go = new JButton("Login");
        login_go.setBounds(200,25);
        login_Panel.add(password_login);
        login_Panel.add(username_login);


        JPanel panel_Divider = new JPanel();                          //PANEL Divider
        login_Panel.setBounds(350,150);
        panel_Divider.setSize(50,100);
        panel_Divider.setLayout(null);
        Image sep = null;
        try {
            sep = ImageIO.read(new File("Data/images/sep.png"));
        } catch (IOException e) {
            e.printStackTrace();
        }
        Graphics2D div = ((BufferedImage) sep).createGraphics();
        panel_Title.paint(div);

        JPanel register_Panel = new JPanel();                         //REGISTER Panel
        register_Panel.setBounds(400,150);
        register_Panel.setLayout(null);

        login_Frame.add(panel_Title);
        login_Frame.add(login_Panel);
        login_Frame.add(panel_Divider);
        login_Frame.add(register_Panel);
        login_Frame.setVisible(true);
    }
}

Error: None

Solution

In addition to all the suggestions made by @ madprogammer, you also need to add controls to the JFrame content pane, as shown below:

login_Frame.getContentPane().add(panel_Title);
login_Frame.getContentPane().add(login_Panel);
...

Then your control should appear

to update:

Running your actual code and adding colored borders to the containers (jpanels), I get the following:

panel_Title.setBorder(BorderFactory.createLineBorder(Color.BLUE));
login_Panel.setBorder(BorderFactory.createLineBorder(Color.RED));
panel_Divider.setBorder(BorderFactory.createLineBorder(Color.GREEN));
register_Panel.setBorder(BorderFactory.createLineBorder(Color.YELLOW));

Basically, your code has layout configuration problems Again, follow @ madprogammer's advice You can use this border technique to debug the layout in the future