> ## Documentation Index
> Fetch the complete documentation index at: https://bun.zhcndoc.com/llms.txt
> Use this file to discover all available pages before exploring further.

# 将文件作为 HTTP 响应流式传输

此示例使用 [`Bun.file()`](/runtime/file-io#reading-files-bun-file) 从磁盘读取文件。该方法返回一个 `BunFile` 实例，可以直接传入 `new Response` 构造函数。

```ts server.ts icon="https://mintcdn.com/bun-zhcndoc/cnUTwgMuf4cCrwC-/icons/typescript.svg?fit=max&auto=format&n=cnUTwgMuf4cCrwC-&q=85&s=e7767043c9e885c34f2d6c8fe2a95217" theme={"theme":{"light":"github-light","dark":"dracula"}}
const path = "/path/to/file.txt";
const file = Bun.file(path);
const resp = new Response(file);
```

***

`Content-Type` 会从文件中读取并自动设置到 `Response` 上。

```ts server.ts icon="https://mintcdn.com/bun-zhcndoc/cnUTwgMuf4cCrwC-/icons/typescript.svg?fit=max&auto=format&n=cnUTwgMuf4cCrwC-&q=85&s=e7767043c9e885c34f2d6c8fe2a95217" theme={"theme":{"light":"github-light","dark":"dracula"}}
new Response(Bun.file("./package.json")).headers.get("Content-Type");
// => application/json;charset=utf-8

new Response(Bun.file("./test.txt")).headers.get("Content-Type");
// => text/plain;charset=utf-8

new Response(Bun.file("./index.tsx")).headers.get("Content-Type");
// => text/javascript;charset=utf-8

new Response(Bun.file("./img.png")).headers.get("Content-Type");
// => image/png
```

***

结合 [`Bun.serve()`](/runtime/http/server) 一起使用。

```ts server.ts icon="https://mintcdn.com/bun-zhcndoc/cnUTwgMuf4cCrwC-/icons/typescript.svg?fit=max&auto=format&n=cnUTwgMuf4cCrwC-&q=85&s=e7767043c9e885c34f2d6c8fe2a95217" theme={"theme":{"light":"github-light","dark":"dracula"}}
// 静态文件服务器
Bun.serve({
  async fetch(req) {
    const path = new URL(req.url).pathname;
    const file = Bun.file(path);
    return new Response(file);
  },
});
```

***

完整的 `Bun.write()` 文档请参见 [文档 > API > 文件 I/O](/runtime/file-io#writing-files-bun-write)。