java后台生成文件给前端下载（response输出流）

1、设置 ContentType

response.setContentType("application/x-download");

2、设置文件名，并指定编码格式

fileName = URLEncoder.encode("浏览器要显示的文件名", "UTF-8");
response.setCharacterEncoding("UTF-8");

3、将文件名 addHeader

response.addHeader("Content-Disposition", "attachment;filename=" + fileName);

4、读取文件流写入 response

File file = new File(filePath);
try {
       InputStream stream = new FileInputStream(file);

       ServletOutputStream out = response.getOutputStream();

       byte buff[] = new byte[1024];
       int length = 0;

       while ((length = stream.read(buff)) > 0) {
            out.write(buff,0,length);
       }
       stream.close();

       out.close();

       out.flush();

} catch (IOException e) {
       e.printStackTrace();
}