Go 言語の一般的なアプリケーション シナリオは何ですか?

package main

import (
    "fmt"
    "log"
    "net/http"

    "github.com/gorilla/mux"
)

func main() {
    router := mux.NewRouter()
    router.HandleFunc("/", HomeHandler).Methods("GET")
    router.HandleFunc("/users", UsersHandler).Methods("GET")
    router.HandleFunc("/users/{id}", UserHandler).Methods("GET")

    fmt.Println("Starting server on port 8080")
    log.Fatal(http.ListenAndServe(":8080", router))
}

func HomeHandler(w http.ResponseWriter, r *http.Request) {
    fmt.Fprint(w, "Hello, world!")
}

func UsersHandler(w http.ResponseWriter, r *http.Request) {
    // Get all users from the database
    users := []User{
        {ID: 1, Name: "Alice"},
        {ID: 2, Name: "Bob"},
        {ID: 3, Name: "Charlie"},
    }

    // Encode the users into JSON and write it to the response
    if err := json.NewEncoder(w).Encode(users); err != nil {
        http.Error(w, "Error encoding users", http.StatusInternalServerError)
    }
}

func UserHandler(w http.ResponseWriter, r *http.Request) {
    // Get the user ID from the request
    id := mux.Vars(r)["id"]

    // Get the user from the database
    user, err := GetUserByID(id)
    if err != nil {
        http.Error(w, "No user found with that ID", http.StatusNotFound)
        return
    }

    // Encode the user into JSON and write it to the response
    if err := json.NewEncoder(w).Encode(user); err != nil {
        http.Error(w, "Error encoding user", http.StatusInternalServerError)
    }
}

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

func GetUserByID(id string) (*User, error) {
    // This function is a placeholder for a more complex implementation that
    // would retrieve a user by ID from a database.
    user := &User{
        ID:   1,
        Name: "Alice",
    }

    return user, nil
}