Make JTextField Read-Only in Java (Not Editable)

In Java's Swing framework, making a JTextField read-only means the user can't modify its content, but can still select and copy the text. This is achieved by using the setEditable method and passing false as its argument.

Make JTextField Read-Only or Not Editable in Java

Here's a simple example demonstrating how to create a read-only JTextField:

import javax.swing.*;
import java.awt.FlowLayout;  

public class ReadOnlyTextFieldDemo {

    public static void main(String[] args) {
        // Create a new JFrame
        JFrame frame = new JFrame("Read Only JTextField Demo");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setSize(300, 200);
        frame.setLayout(new FlowLayout());

        // Create a JTextField
        JTextField textField = new JTextField(20);

        // Set some text
        textField.setText("This is read-only text.");

        // Make the JTextField read-only
        textField.setEditable(false);

        // Add the JTextField to the JFrame
        frame.add(textField);

        // Display the JFrame
        frame.setVisible(true);
    }
}

Output:

Explanation Step-By-Step:

Imports java:

import javax.swing.*;
import java.awt.FlowLayout;  

These are the libraries you're importing: 

javax.swing.*: This is Java's built-in library for creating graphical user interfaces. The * means you're importing all classes from this package, but in this specific code, you are utilizing JFrame and JTextField from the Swing package.

java.awt.FlowLayout: FlowLayout is a layout manager which arranges components in a left-to-right flow, similar to how paragraphs flow in text.

JFrame Initialization:

        // Create a new JFrame
        JFrame frame = new JFrame("Read Only JTextField Demo");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setSize(300, 200);
        frame.setLayout(new FlowLayout());

• A new JFrame is created, which is essentially a window with a title "Read Only JTextField Demo".
• setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE) ensures that when you close the JFrame (by clicking the close button), the entire application will shut down. 
• frame.setSize(300, 200) sets the size of the frame to be 300 pixels wide and 200 pixels tall. 
• frame.setLayout(new FlowLayout()) sets the layout manager of the frame to be FlowLayout. This means any components added to this frame will be arranged from left to right.

JTextField Initialization:

JTextField textField = new JTextField(20);
textField.setText("This is read-only text.");
textField.setEditable(false);

• A new JTextField is created with a width that approximately fits 20 columns of characters. 
• setText method sets an initial text into the text field: "This is read-only text.". textField.setEditable(false) makes the JTextField read-only, so users cannot modify the content.

Adding JTextField to JFrame:

        // Add the JTextField to the JFrame
        frame.add(textField);

This line adds the textField component to the frame. Due to the FlowLayout layout manager, it will be positioned from left to right. 

Remember to keep in mind that making the JTextField non-editable only prevents the user from modifying its content through the GUI. It doesn't prevent the program itself from changing the content programmatically.