How do I style some texts in the Paragraph object in iText 8?

In iText 8, if you want to style only part of the text inside a Paragraph object, you can use the Text object to encapsulate the text that needs separate styling.

Here’s an example:

package org.kodejava.itext;

import com.itextpdf.kernel.pdf.PdfDocument;
import com.itextpdf.kernel.pdf.PdfWriter;
import com.itextpdf.kernel.font.PdfFont;
import com.itextpdf.kernel.font.PdfFontFactory;
import com.itextpdf.kernel.colors.DeviceRgb;
import com.itextpdf.layout.Document;
import com.itextpdf.layout.element.Paragraph;
import com.itextpdf.layout.element.Text;
import com.itextpdf.io.font.constants.StandardFonts;

public class ParagraphTextExample {
    public static void main(String[] args) throws Exception {
        PdfWriter writer = new PdfWriter("styled-text.pdf");
        PdfDocument pdf = new PdfDocument(writer);

        try (Document document = new Document(pdf)) {

            PdfFont font = PdfFontFactory.createFont(StandardFonts.HELVETICA);

            // Create a Text object and style it
            Text text1 = new Text("This text is green and super bold. ")
                    .setFont(font)
                    .setFontSize(15)
                    .setFontColor(new DeviceRgb(0, 255, 0))
                    .setBold();

            // Create another Text object and style it differently
            Text text2 = new Text("This text is blue and italic. ")
                    .setFont(font)
                    .setFontSize(12)
                    .setFontColor(new DeviceRgb(0, 0, 255))
                    .setItalic();

            // Create another Text object and style it differently
            final String text = """
                    What's in a name? \
                    That which we call a rose by any other name \
                    would smell just as sweet.
                    """;
            Text text3 = new Text(text)
                    .setFont(font)
                    .setFontSize(20)
                    .setFontColor(new DeviceRgb(243, 58, 106))
                    .setBold()
                    .setItalic();

            // Add Text objects to a single Paragraph
            Paragraph paragraph = new Paragraph().add(text1).add(text2).add(text3);

            document.add(paragraph);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

In this example, three Text objects, text1, text2, and text3, are created with different styles. The Text objects are then added to a Paragraph object. As a result, the paragraph will have mixed styles, depending on the individual text elements.

Notably, you can apply a rich variety of styling on the Text objects, including font, size, color, background color, underlines, strike-through, superscripts, subscripts, and nearly any other style applicable to text.

Maven Dependencies

<dependency>
    <groupId>com.itextpdf</groupId>
    <artifactId>itext-core</artifactId>
    <version>8.0.4</version>
    <type>pom</type>
</dependency>

Maven Central

How do I replace text in the JTextArea?

In this example you’ll see how to use the replaceRange(String str, int start, int end) method to replace a string in the JTextArea from the start position to the end position with the specified string.

package org.kodejava.swing;

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

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

    public static void showFrame() {
        JPanel panel = new TextAreaReplaceText();
        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(TextAreaReplaceText::showFrame);
    }

    private void initializeUI() {
        String text = "The quick white fox jumps over the sleepy dog.";

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

        textArea.replaceRange("brown", 10, 15);
        textArea.replaceRange("lazy", 35, 41);

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

The screenshot of the code snippet above is:

JTextArea Replace Text Demo

How do I set and get the contents of JTextArea?

To set and get the contents of a JTextArea you can use the setText(String text) and getText() methods. In the code below we create a JTextArea and sets its contents after we create a new instance of JTextArea. To get the contents we use the action on a button. When the button is pressed the contents of the JTextArea is read using the getText() method. This method return a String object.

package org.kodejava.swing;

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

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

    public static void showFrame() {
        JPanel panel = new TextAreaGetContent();
        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(TextAreaGetContent::showFrame);
    }

    private void initializeUI() {
        this.setLayout(new BorderLayout());
        this.setPreferredSize(new Dimension(500, 200));

        final JTextArea textArea = new JTextArea();

        // Set the contents of the JTextArea.
        String text = "The quick brown fox jumps over the lazy dog.";
        textArea.setText(text);
        textArea.setLineWrap(true);
        textArea.setWrapStyleWord(true);

        JScrollPane pane = new JScrollPane(textArea);
        pane.setPreferredSize(new Dimension(500, 200));
        pane.setVerticalScrollBarPolicy(
                JScrollPane.VERTICAL_SCROLLBAR_ALWAYS);

        JButton button = new JButton("Get Contents");
        button.addActionListener(e -> {
            // Get the contents of the JTextArea component.
            String contents = textArea.getText();
            System.out.println("contents = " + contents);
        });

        this.add(pane, BorderLayout.CENTER);
        this.add(button, BorderLayout.SOUTH);
    }
}

The output of the code snippet above is:

Set and Get the Content of JTextArea