ResponseUtil

import cn.hutool.core.net.URLEncodeUtil;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.nio.charset.StandardCharsets;
import java.util.Enumeration;

/**
 * @author: xjc
 * @Date: 2022/10/7
 * @Description:
 */
public class ResponseUtil {

    private static String DEFAULT_CONTENT_TYPE = "application/octet-stream";

    public static void setHeader(HttpServletRequest request, HttpServletResponse response, String fileName) {

        String contentType = parseContentType(request);

        response.setCharacterEncoding("utf-8");
        response.setContentType(contentType);

        // 文件名称
        fileName = URLEncodeUtil.encode(fileName, StandardCharsets.UTF_8);
        response.setHeader("Content-Disposition",
                String.format("attachment;fileName=%s", fileName));

    }

    private static String parseContentType(HttpServletRequest request) {
        Enumeration<String> headers = request.getHeaders("Content-Type");
        if (!headers.hasMoreElements()) {
            return DEFAULT_CONTENT_TYPE;
        }
        String contentType = headers.nextElement();
        contentType = null == contentType ? DEFAULT_CONTENT_TYPE : contentType;
        return contentType;
    }
}