如何用Golang编写一个处理GET和POST请求的简单JSON API

package main

import (
    "encoding/json"
    "log"
    "net/http"
)

func main() {
    http.HandleFunc("/api/data", handleData)
    log.Println("Server starting on :8080")
    log.Fatal(http.ListenAndServe(":8080", nil))
}

type Data struct {
    ID   int    `json:"id"`
    Name string `json:"name"`
}

func handleData(w http.ResponseWriter, r *http.Request) {
    switch r.Method {
    case "GET":
        data := Data{ID: 1, Name: "example"}
        w.Header().Set("Content-Type", "application/json")
        json.NewEncoder(w).Encode(data)

    case "POST":
        // 处理POST见下文
    default:
        http.Error(w, "Method not allowed", http.StatusMethodNotAllowed)
    }
}

case "POST":
    var data Data
    if err := json.NewDecoder(r.Body).Decode(&data); err != nil {
        http.Error(w, "Invalid JSON", http.StatusBadRequest)
        return
    }

    // 简单响应，回显收到的数据
    response := map[string]string{
        "status": "received",
        "id":     fmt.Sprintf("%d", data.ID),
        "name":   data.Name,
    }

    w.Header().Set("Content-Type", "application/json")
    w.WriteHeader(http.StatusCreated)
    json.NewEncoder(w).Encode(response)

go run main.go

curl -X GET http://localhost:8080/api/data

curl -X POST http://localhost:8080/api/data \
     -H "Content-Type: application/json" \
     -d '{"id": 2, "name": "test"}'