To append text to the end of the JTextArea document we can use the append(String str) method. This method does nothing if the document is null or the string is null or empty.

package org.kodejava.example.swing;

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

public class TextAreaAppendText extends JPanel {
    public TextAreaAppendText() {
        initializeUI();
    }

    private void initializeUI() {
        String text = "The quick brown fox ";

        JTextArea textArea = new JTextArea(text);
        textArea.setLineWrap(true);
        textArea.setWrapStyleWord(true);
        JScrollPane scrollPane = new JScrollPane(textArea);

        String appendText = "jumps over the lazy dog.";
        textArea.append(appendText);

        this.setPreferredSize(new Dimension(500, 200));
        this.setLayout(new BorderLayout());
        this.add(scrollPane, BorderLayout.CENTER);
    }

    public static void showFrame() {
        JPanel panel = new TextAreaAppendText();
        panel.setOpaque(true);

        JFrame frame = new JFrame("JTextArea Demo");
        frame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
        frame.setContentPane(panel);
        frame.pack();
        frame.setVisible(true);
    }

    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                TextAreaAppendText.showFrame();
            }
        });
    }
}

The output of the code snippet above is:

JTextArea Append Text Demo

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Wayan Saryada

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I am a programmer, a runner, a recreational diver, currently live in the island of Bali, Indonesia. Mostly programming in Java, Spring Framework, Hibernate / JPA. You can support my works by donating here. Thank you 🥳

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