<repositories>
    <repository>
        <id>com.e-iceblue</id>
        <name>e-iceblue</name>
        <url>https://repo.e-iceblue.com/nexus/content/groups/public/</url>
    </repository>
</repositories>
<dependencies>
    <dependency>
        <groupId>e-iceblue</groupId>
        <artifactId>spire.doc</artifactId>
        <version>13.11.2</version>
    </dependency>
</dependencies>

import com.spire.doc.*;
import com.spire.doc.documents.DocumentObjectType;
import com.spire.doc.documents.Paragraph;
import com.spire.doc.fields.TextBox;

import java.io.FileWriter;
import java.io.IOException;

public class ExtractTextFromTextbox {

    public static void main(String[] args) throws IOException {

        // Create a Document object
        Document document = new Document();

        // Load a Word file
        document.loadFromFile("C:\\Users\\Administrator\\Desktop\\Input.docx");

        // Get a specific textbox
        TextBox textBox = document.getTextBoxes().get(0);

        // Create a FileWriter to write extracted text to a txt file
        FileWriter fileWriter = new FileWriter("Extracted.txt");

        // Iterate though child objects of the textbox
        for (Object object: textBox.getChildObjects()) {

            // Determine if the child object is a paragraph
            if (((DocumentObject) object).getDocumentObjectType() == DocumentObjectType.Paragraph) {

                // Write paragraph text to the txt file
                fileWriter.write(((Paragraph)object).getText() + "\n");
            }

            // Determine if the child object is a table
            if (((DocumentObject) object).getDocumentObjectType() == DocumentObjectType.Table) {

                // Extract text from table to the txt file
                extractTextFromTable((Table)object, fileWriter);
            }
        }

        // Close the stream
        fileWriter.close();
    }

    // Extract text from a table
    static void extractTextFromTable(Table table, FileWriter fileWriter) throws IOException {
        for (int i = 0; i < table.getRows().getCount(); i++) {
            TableRow row = table.getRows().get(i);
            for (int j = 0; j < row.getCells().getCount(); j++) {
                TableCell cell = row.getCells().get(j);
                for (Object paragraph: cell.getParagraphs()) {
                    fileWriter.write(((Paragraph) paragraph).getText() + "\n");
                }
            }
        }
    }
}

import com.spire.doc.Document;
import com.spire.doc.FileFormat;
import com.spire.doc.documents.Paragraph;
import com.spire.doc.fields.TextBox;
import com.spire.doc.fields.TextRange;

public class UpdateTextbox {

    public static void main(String[] args) {

        // Create a Document object
        Document document = new Document();

        // Load a Word file
        document.loadFromFile("C:\\Users\\Administrator\\Desktop\\Input.docx");

        // Get a specific textbox
        TextBox textBox = document.getTextBoxes().get(0);

        // Remove child objects of the textbox
        textBox.getChildObjects().clear();

        // Add a new paragraph to the textbox
        Paragraph paragraph = textBox.getBody().addParagraph();

        // Set line spacing
        paragraph.getFormat().setLineSpacing(15f);

        // Add text to the paragraph
        TextRange textRange = paragraph.appendText("The text in this textbox has been updated.");

        // Set font size
        textRange.getCharacterFormat().setFontSize(15f);

        // Save the document to a different Word file
        document.saveToFile("UpdateTextbox.docx", FileFormat.Docx_2019);

        // Dispose resources
        document.dispose();
    }
}