前端请求Java应用导出，使用HttpServletResponse导出时，HttpServletResponse会断开网络的问题记录

import com.alibaba.fastjson.JSONObject;
import org.apache.poi.ss.usermodel.*;
import org.apache.poi.util.IOUtils;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;
import org.springframework.web.bind.annotation.*;

import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.URL;
import java.util.Map;
import java.util.concurrent.CompletableFuture;
import java.util.concurrent.ExecutionException;

@RestController
@RequestMapping("/test")
public class TestController {

    @GetMapping("/export")
    @ResponseBody
    public void export(@RequestParam Map<String, Object> params, HttpServletResponse response) {
        System.out.println("导出测试，params={}" + JSONObject.toJSONString(params));

        // 设置 Content-Type 头部信息
        response.setContentType("application/vnd.openxmlformats-officedocument.spreadsheetml.sheet");
        // 设置 Content-Disposition 头部信息，指定文件名
        response.setHeader("Content-Disposition", "attachment; filename=\"example.xlsx\"");
        try {
            // 通过 Apache POI 创建 Workbook 对象并向 HttpServletResponse 的输出流中写入数据
            //Workbook workbook = createExcelWorkbook(); // 创建 Workbook 对象的方法需要根据具体业务逻辑来实现
            /**
             * 将上述代码直接放在一个 Web 应用程序中，可能会出现响应断开的问题。
             * 这是因为在处理 HTTP 请求时，需要确保在将响应发送给客户端之前，所有的数据都已经写入到输出流中。
             */
            // 解决：把 createExcelWorkbook()放入异步中
            // 创建1个异步任务，每个任务返回一个结果
            CompletableFuture<XSSFWorkbook> workbookFuture = CompletableFuture.supplyAsync(() -> {
                XSSFWorkbook workbook = null;
                try {
                    // 生成表格
                    workbook = createExcelWorkbook();
                } catch (Exception e) {
                    e.printStackTrace();
                }
                return workbook;
            });

            // 使用allOf等待所有任务完成
            CompletableFuture<Void> allFutures = CompletableFuture.allOf(workbookFuture);

            // 当所有任务完成后，可以进一步处理结果
            CompletableFuture<XSSFWorkbook> finalResult = allFutures.thenApply(v -> {
                try {
                    // 获取并处理所有任务的结果
                    XSSFWorkbook workbook = workbookFuture.get();
                    return workbook;
                } catch (InterruptedException | ExecutionException e) {
                    throw new RuntimeException(e);
                }
            });
            // 阻塞等待最终结果
            XSSFWorkbook workbook = finalResult.get();
            OutputStream outputStream = response.getOutputStream();
            workbook.write(outputStream);
            outputStream.flush();
        } catch (IOException e) {
            // 处理异常
        } catch (ExecutionException e) {
            e.printStackTrace();
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
    }

    public XSSFWorkbook createExcelWorkbook() throws IOException {
        // 创建新的 Excel 工作簿
        Workbook workbook = new XSSFWorkbook();
        Sheet sheet = workbook.createSheet("Images");

        // 从 URL 中获取图片数据
        URL imageUrl = new URL("https://example.com/image.jpg");
        InputStream imageStream = imageUrl.openStream();
        byte[] imageBytes = IOUtils.toByteArray(imageStream);
        imageStream.close();

        // 将图片数据插入到 Excel 中
        int pictureIdx = workbook.addPicture(imageBytes, Workbook.PICTURE_TYPE_JPEG);
        CreationHelper helper = workbook.getCreationHelper();
        Drawing<?> drawing = sheet.createDrawingPatriarch();
        ClientAnchor anchor = helper.createClientAnchor();
        anchor.setCol1(1);
        anchor.setRow1(1);
        Picture pict = drawing.createPicture(anchor, pictureIdx);
        pict.resize(1, 1);
        return (XSSFWorkbook) workbook;
    }

}