如何从springMVC中的REST响应返回powerpoint (.pptx)文件

import org.apache.poi.xslf.usermodel.XMLSlideShow;
import org.apache.poi.xslf.usermodel.XSLFSlide;
import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpStatus;
import org.springframework.http.MediaType;
import org.springframework.http.ResponseEntity;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.GetMapping;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;

@Controller
public class PowerPointController {

    @GetMapping("/download")
    public ResponseEntity<byte[]> downloadPowerPoint() throws IOException {
        // 创建一个新的PowerPoint文档
        XMLSlideShow ppt = new XMLSlideShow();

        // 创建一个幻灯片
        XSLFSlide slide = ppt.createSlide();

        // 在幻灯片上添加内容

        // ...

        // 将PowerPoint文档保存到临时文件
        File tempFile = File.createTempFile("temp", ".pptx");
        FileOutputStream out = new FileOutputStream(tempFile);
        ppt.write(out);
        out.close();

        // 将临时文件的内容读取为字节数组
        byte[] pptBytes = Files.readAllBytes(tempFile.toPath());

        // 设置响应头
        HttpHeaders headers = new HttpHeaders();
        headers.setContentType(MediaType.APPLICATION_OCTET_STREAM);
        headers.setContentDispositionFormData("attachment", "presentation.pptx");

        // 返回PowerPoint文件的字节数组
        return new ResponseEntity<>(pptBytes, headers, HttpStatus.OK);
    }
}