Java Swing：JLabel 文本未出现在屏幕上

Question

I'm trying to get a name input from the Scanner and display that on the screen through a JLabel . However, it is not appearing. The button that I made appears, but the label does not. Am I missing something?

import javax.swing.*;
import java.awt.*; 
import java.util.*; 
import java.lang.*; 

public class MyProgram {
   
    public static void main(String[] args) {
        //creating instance of JFrame
        
        JFrame f= new JFrame();
        JButton b1 = new JButton("Generate Password");
        b1.setBounds(90, 100, 180, 40);
        f.add(b1);
        b1.setBackground(Color.RED);
        b1.setOpaque(true);
        f.setSize(500, 500);
        f.setLayout(null);
        f.setVisible(true);
        Scanner sc = new Scanner(System.in);
        System.out.println("What is your name?"); 
        String name = sc.nextLine(); 
        JLabel n = new JLabel(); 
        n.setBounds(400, 100, 30, 30);
        n.setText(name + "'s Password Generator!");
        f.add(n);
    }
}

Answer 1

1. You're mixing a GUI- with a Console-Application. Is this really what you want?
2. You're nulling the Layout of your JFrame . Why do you do this? You basically always need layouting. Have a look at this guide.

Your JLabel is indeed showing. Try to resize your JFrame after you typed in your name, you should see your JLabel then. The JLabel will always appear, if you call setVisible(true) at the end of your program. This is because your JFrame gets painted when you call setVisible(true) . If you add another component to it, the JFrame is not repainted. If you resize it, it will be repainted.

However, you should have a look at basic Java Swing tutorials .