如何在java中创建pdf后立即下载

<dependency>
    <groupId>org.apache.pdfbox</groupId>
    <artifactId>pdfbox</artifactId>
    <version>2.0.24</version>
</dependency>

import org.apache.pdfbox.pdmodel.PDDocument;
import org.apache.pdfbox.pdmodel.PDPage;
import org.apache.pdfbox.pdmodel.common.PDRectangle;
import org.apache.pdfbox.pdmodel.PDPageContentStream;
import org.apache.pdfbox.pdmodel.font.PDType1Font;

import java.io.IOException;

public class PDFCreator {
    public static void main(String[] args) {
        try {
            PDDocument document = new PDDocument();
            PDPage page = new PDPage(PDRectangle.A4);
            document.addPage(page);

            PDPageContentStream contentStream = new PDPageContentStream(document, page);
            contentStream.setFont(PDType1Font.HELVETICA_BOLD, 12);
            contentStream.beginText();
            contentStream.newLineAtOffset(50, 700);
            contentStream.showText("Hello, PDF!");
            contentStream.endText();
            contentStream.close();

            document.save("sample.pdf");
            document.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.OutputStream;

public class PDFDownloadServlet extends HttpServlet {
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws IOException {
        response.setContentType("application/pdf");
        response.addHeader("Content-Disposition", "attachment; filename=sample.pdf");

        File file = new File("sample.pdf");
        FileInputStream fileInputStream = new FileInputStream(file);
        OutputStream outputStream = response.getOutputStream();

        byte[] buffer = new byte[4096];
        int length;
        while ((length = fileInputStream.read(buffer)) > 0) {
            outputStream.write(buffer, 0, length);
        }

        outputStream.flush();
        outputStream.close();
        fileInputStream.close();
    }
}