Display Bold Text Inside JTextArea in Java

JTextArea is one of the most common Swing-based components. By default, it does not support text formatting such as bold, italics, or colored text inside a textarea. In this article, we will learn to display bold text inside the JTextArea in Java.

What is a JTextArea?

A JTextArea class can extend JTextComponent and allow a user to enter multiple lines of text inside it. A JTextArea can generate a CaretListener interface, which can listen to caret update events.

Syntax

The following is the syntax for JTextArea initialization:

JTextArea textArea = new JTextArea();

Adding Bold Text Inside the JTextArea

We can set a font to a text inside the JTextArea by using the setFont() method. The following are the steps for displaying bold text inside the JTextArea in Java:

Class Declaration and Imports

The javax.swing.* provides Swing components (JTextArea, JFrame, etc.) while the java.awt.* provides AWT classes (size, layout managers), and the class extends JFrame to create a window.

import java.awt.*;
import javax.swing.*;
public class JTextAreaTextBoldTest extends JFrame {

Instance Variable & Constructor Setup

The textArea variable is declared using JTextArea. The constructor initializes the JFrame window with the title "JTextAreaTextBold Test" and sets BorderLayout as the layout manager.

private JTextArea textArea;
public JTextAreaTextBoldTest() {
      setTitle("JTextAreaTextBold Test");
      setLayout(new BorderLayout());

JTextArea Setup

Creates a new JTextArea, then setLineWrap(true), which enables line wrapping, and setWrapStyleWord(true), so words are not broken in the middle of a line.

textArea = new JTextArea();
textArea.setLineWrap(true);
textArea.setWrapStyleWord(true);

Applying Bold Font

Create a new font with the same name and size but bold style, and use this font on the JTextArea by using the setFont() method.

Font boldFont = new Font(textArea.getFont().getName(), Font.BOLD, textArea.getFont().getSize());
textArea.setFont(boldFont);

Main Method

The main method launches the application by creating an object of JTextAreaTextBoldTest.

public static void main(String[] args) {
    new JTextAreaTextBoldTest();
}

Example

Below is an example of displaying bold text inside the JTextArea in Java using the setFont() method:

import java.awt.*;
import javax.swing.*;
public class JTextAreaTextBoldTest extends JFrame {
   private JTextArea textArea;
   public JTextAreaTextBoldTest() {
      setTitle("JTextAreaTextBold Test");
      setLayout(new BorderLayout());
      textArea= new JTextArea();
      textArea.setLineWrap(true);
      textArea.setWrapStyleWord(true);
      Font boldFont=new Font(textArea.getFont().getName(), Font.BOLD, textArea.getFont().getSize());
      textArea.setFont(boldFont); // bold text 
      add(textArea);
      setSize(375, 250);
      setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
      setLocationRelativeTo(null);
      setVisible(true);
   }
   public static void main(String[]args) {
      new JTextAreaTextBoldTest();
   }
}

Output