Go语言HTTP服务接收二进制数据指南

package main

import (
    "fmt"
    "io/ioutil"
    "log"
    "net/http"
)

// min returns the smaller of x or y.
func min(x, y int) int {
    if x < y {
        return x
    }
    return y
}

// handleReadIntoMemory 处理将请求体完整读取到内存的请求
func handleReadIntoMemory(w http.ResponseWriter, req *http.Request) {
    // 确保只处理 POST 请求
    if req.Method != http.MethodPost {
        http.Error(w, "Only POST method is allowed", http.StatusMethodNotAllowed)
        return
    }

    // 读取整个请求体到字节切片
    buf, err := ioutil.ReadAll(req.Body)
    if err != nil {
        http.Error(w, fmt.Sprintf("Failed to read request body: %v", err), http.StatusInternalServerError)
        log.Printf("Error reading request body: %v", err)
        return
    }

    // 实际应用中，这里会对 buf 进行处理，例如保存到数据库、解析、校验等
    log.Printf("Received %d bytes of binary data into memory.", len(buf))
    // 示例：打印前10个字节
    if len(buf) > 0 {
        log.Printf("First %d bytes: %x...\n", min(len(buf), 10), buf[:min(len(buf), 10)])
    }

    w.WriteHeader(http.StatusOK)
    w.Write([]byte(fmt.Sprintf("Binary data received (%d bytes) and processed in memory.", len(buf))))
}

func main() {
    http.HandleFunc("/upload-memory", handleReadIntoMemory)
    log.Println("Server started on :8080, listening for /upload-memory...")
    log.Fatal(http.ListenAndServe(":8080", nil))
}

package main

import (
    "fmt"
    "io"
    "io/ioutil" // 用于创建临时文件
    "log"
    "net/http"
    "os" // 用于删除临时文件
)

// handleStreamToFile 处理将请求体流式传输到文件的请求
func handleStreamToFile(w http.ResponseWriter, req *http.Request) {
    if req.Method != http.MethodPost {
        http.Error(w, "Only POST method is allowed", http.StatusMethodNotAllowed)
        return
    }

    // 确保请求体在处理完成后关闭，释放资源
    defer req.Body.Close()

    // 创建一个临时文件来存储上传的二进制数据
    // ioutil.TempFile("", "uploaded-binary-") 会在系统默认临时目录创建文件
    // 文件名类似 uploaded-binary-123456789
    tempFile, err := ioutil.TempFile("", "uploaded-binary-")
    if err != nil {
        http.Error(w, fmt.Sprintf("Failed to create temporary file: %v", err), http.StatusInternalServerError)
        log.Printf("Error creating temp file: %v", err)
        return
    }
    // 确保临时文件句柄关闭
    defer tempFile.Close()
    // 确保临时文件在函数返回时被删除，防止文件堆积
    defer func() {
        if err := os.Remove(tempFile.Name()); err != nil {
            log.Printf("Error deleting temporary file %s: %v", tempFile.Name(), err)
        } else {
            log.Printf("Temporary file %s deleted successfully.", tempFile.Name())
        }
    }()

    // 将请求体内容拷贝到临时文件
    bytesCopied, err := io.Copy(tempFile, req.Body)
    if err != nil {
        http.Error(w, fmt.Sprintf("Failed to write data to temporary file: %v", err), http.StatusInternalServerError)
        log.Printf("Error copying data to temp file: %v", err)
        return
    }

    log.Printf("Received %d bytes of binary data and saved to temporary file: %s\n", bytesCopied, tempFile.Name())
    w.WriteHeader(http.StatusOK)
    w.Write([]byte(fmt.Sprintf("Binary data received (%d bytes) and saved to %s.", bytesCopied, tempFile.Name())))
}

func main() {
    // 注册两种处理方式的路由
    http.HandleFunc("/upload-memory", handleReadIntoMemory) // 方法一的处理器
    http.HandleFunc("/upload-stream", handleStreamToFile)   // 方法二的处理器
    log.Println("Server started on :8080, listening for /upload-memory and /upload-stream...")
    log.Fatal(http.ListenAndServe(":8080", nil))
}