需求： 开始 --> 读取文件 --> 将文件流返回给前端 --> 结束

1、读取文件

<code>// 读取文件

File file = new File("path/to/your/file.txt"); // 文件路径

FileInputStream fis = new FileInputStream(file);

2、将文件流返回给前端 

// 将文件流返回给前端

response.setContentType("application/octet-stream");

response.setHeader("Content-Disposition", "attachment; filename=\"" + file.getName() + "\"");

OutputStream outputStreams = response.getOutputStream();

byte[] buffer = new byte[1024];

int len;

while ((len = fis.read(buffer)) != -1) {

outputStreams.write(buffer, 0, len);

}

outputStreams .flush();

fis.close();

outputStreams.close();