如何在BufferReader读取的文本中添加换行符以尝试用iText7将其转换为pdf

import com.itextpdf.kernel.pdf.PdfDocument;
import com.itextpdf.kernel.pdf.PdfWriter;
import com.itextpdf.layout.Document;
import com.itextpdf.layout.element.Paragraph;

import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;

public class TextToPdfConverter {
    public static void main(String[] args) {
        String inputFile = "input.txt";
        String outputFile = "output.pdf";

        try {
            // 创建PDF文档
            PdfDocument pdfDoc = new PdfDocument(new PdfWriter(outputFile));
            Document doc = new Document(pdfDoc);

            // 使用BufferedReader逐行读取文本文件并添加换行符
            BufferedReader reader = new BufferedReader(new FileReader(inputFile));
            StringBuilder sb = new StringBuilder();
            String line;
            while ((line = reader.readLine()) != null) {
                sb.append(line).append("\n"); // 添加换行符
            }
            reader.close();

            // 将StringBuilder对象转换为字符串，并将文本写入PDF
            String text = sb.toString();
            doc.add(new Paragraph(text));

            // 关闭PDF文档
            doc.close();
            System.out.println("PDF生成成功！");
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}