🌐 Bài 18: HTTP Server

package main

import (
    "fmt"
    "net/http"
)

func main() {
    // Handler cho route "/"
    http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
        fmt.Fprintf(w, "Hello, World!")
    })
    
    fmt.Println("Server running at http://localhost:8080")
    http.ListenAndServe(":8080", nil)
}

func homeHandler(w http.ResponseWriter, r *http.Request) {
    fmt.Fprintf(w, "Trang chủ")
}

func aboutHandler(w http.ResponseWriter, r *http.Request) {
    fmt.Fprintf(w, "Giới thiệu")
}

func main() {
    http.HandleFunc("/", homeHandler)
    http.HandleFunc("/about", aboutHandler)
    
    http.ListenAndServe(":8080", nil)
}

// URL: /greet?name=Minh&age=25

func greetHandler(w http.ResponseWriter, r *http.Request) {
    name := r.URL.Query().Get("name")
    age := r.URL.Query().Get("age")
    
    if name == "" {
        name = "Guest"
    }
    
    fmt.Fprintf(w, "Xin chào %s, %s tuổi!", name, age)
}

func userHandler(w http.ResponseWriter, r *http.Request) {
    switch r.Method {
    case "GET":
        fmt.Fprintf(w, "Lấy danh sách users")
    case "POST":
        fmt.Fprintf(w, "Tạo user mới")
    case "PUT":
        fmt.Fprintf(w, "Cập nhật user")
    case "DELETE":
        fmt.Fprintf(w, "Xóa user")
    default:
        http.Error(w, "Method không hỗ trợ", 
            http.StatusMethodNotAllowed)
    }
}

import (
    "io"
    "net/http"
)

func createHandler(w http.ResponseWriter, r *http.Request) {
    if r.Method != "POST" {
        http.Error(w, "Chỉ chấp nhận POST", 
            http.StatusMethodNotAllowed)
        return
    }
    
    // Đọc body
    body, err := io.ReadAll(r.Body)
    if err != nil {
        http.Error(w, "Lỗi đọc body", 
            http.StatusBadRequest)
        return
    }
    defer r.Body.Close()
    
    fmt.Fprintf(w, "Nhận được: %s", string(body))
}

func main() {
    // Serve files từ thư mục "static"
    fs := http.FileServer(http.Dir("static"))
    http.Handle("/static/", http.StripPrefix("/static/", fs))
    
    http.HandleFunc("/", homeHandler)
    http.ListenAndServe(":8080", nil)
}