Create main.go

Author: danglinhanh

main.go

@@ -0,0 +1,80 @@
+package main
+
+import (
+	"encoding/json"
+	"fmt"
+	"log"
+	"math/rand"
+	"net/http"
+	"strconv"
+	"sync"
+)
+
+type Book struct {
+	ID     int    `json:"id"`
+	Title  string `json:"title"`
+	Author string `json:"author"`
+}
+
+var (
+	books = make([]Book, 0)
+	mu    sync.Mutex
+)
+
+func main() {
+	http.HandleFunc("/books", booksHandler)
+	http.HandleFunc("/books/", bookByIDHandler)
+	fmt.Println("Server running at http://localhost:8080")
+	log.Fatal(http.ListenAndServe(":8080", nil))
+}
+
+func booksHandler(w http.ResponseWriter, r *http.Request) {
+	switch r.Method {
+	case http.MethodGet:
+		mu.Lock()
+		defer mu.Unlock()
+		json.NewEncoder(w).Encode(books)
+
+	case http.MethodPost:
+		var b Book
+		if err := json.NewDecoder(r.Body).Decode(&b); err != nil {
+			http.Error(w, "Invalid JSON", http.StatusBadRequest)
+			return
+		}
+		mu.Lock()
+		b.ID = rand.Intn(1000000)
+		books = append(books, b)
+		mu.Unlock()
+		w.WriteHeader(http.StatusCreated)
+		json.NewEncoder(w).Encode(b)
+
+	default:
+		http.Error(w, "Method not allowed", http.StatusMethodNotAllowed)
+	}
+}
+
+func bookByIDHandler(w http.ResponseWriter, r *http.Request) {
+	idStr := r.URL.Path[len("/books/"):]
+	id, err := strconv.Atoi(idStr)
+	if err != nil {
+		http.Error(w, "Invalid ID", http.StatusBadRequest)
+		return
+	}
+
+	mu.Lock()
+	defer mu.Unlock()
+
+	for i, b := range books {
+		if b.ID == id {
+			if r.Method == http.MethodDelete {
+				books = append(books[:i], books[i+1:]...)
+				w.WriteHeader(http.StatusNoContent)
+				return
+			}
+			json.NewEncoder(w).Encode(b)
+			return
+		}
+	}
+
+	http.NotFound(w, r)
+}