如何使用 Golang 发送流数据请求？

package main

import (
    "bytes"
    "fmt"
    "io"
    "net/http"
    "time"
)

func main() {
    url := "http://localhost:8080"
    reader := bytes.NewReader([]byte("this is a streamed request"))

    req, err := http.NewRequest("POST", url, reader)
    if err != nil {
        fmt.Println(err)
        return
    }
    req.Header.Set("Content-Type", "application/octet-stream")
    req.ContentLength = -1 // 设置 Content-Length 为 -1 以指示流请求

    // 使用 PipeReader 来创建管道
    reader, writer := io.Pipe()

    // 在Goroutine中从管道写入数据
    go func() {
        time.Sleep(500 * time.Millisecond) // 等待 500 毫秒
        for i := 0; i < 10; i++ {
            fmt.Fprintln(writer, fmt.Sprintf("line %d", i))
            time.Sleep(500 * time.Millisecond) // 每写一行休眠 500 毫秒
        }
        writer.Close()
    }()

    // 将管道连接到请求主体
    req.Body = reader

    // 发送请求
    resp, err := http.DefaultClient.Do(req)
    if err != nil {
        fmt.Println(err)
        return
    }
    defer resp.Body.Close()

    // 读取并打印服务器响应
    body, err := io.ReadAll(resp.Body)
    if err != nil {
        fmt.Println(err)
        return
    }
    fmt.Println(string(body))
}