Add Chapter 6: Web API Project - Full Stack Go Service with Middleware, DB, and Docker

chapters/chapter-6/go.mod

@@ -0,0 +1,3 @@
+module task-api
+
+go 1.21

chapters/chapter-6/main.go

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+package main
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"log"
+	"net/http"
+	"os"
+	"os/signal"
+	"syscall"
+	"time"
+)
+
+// 模型
+type Task struct {
+	ID          int64     `json:"id"`
+	Title       string    `json:"title"`
+	Description string    `json:"description"`
+	Status      string    `json:"status"`
+	Priority    int       `json:"priority"`
+	CreatedAt   time.Time `json:"created_at"`
+	UpdatedAt   time.Time `json:"updated_at"`
+}
+
+// 响应
+type Response struct {
+	Code    int         `json:"code"`
+	Message string      `json:"message"`
+	Data    interface{} `json:"data,omitempty"`
+}
+
+// 内存存储（模拟数据库）
+var tasks = make(map[int64]*Task)
+var nextID int64 = 1
+
+// Handler
+func createTask(w http.ResponseWriter, r *http.Request) {
+	var task Task
+	if err := json.NewDecoder(r.Body).Decode(&task); err != nil {
+		respondError(w, http.StatusBadRequest, "invalid request body")
+		return
+	}
+
+	if task.Title == "" {
+		respondError(w, http.StatusBadRequest, "title is required")
+		return
+	}
+
+	task.ID = nextID
+	nextID++
+	task.Status = "todo"
+	task.CreatedAt = time.Now()
+	task.UpdatedAt = time.Now()
+	tasks[task.ID] = &task
+
+	respondJSON(w, http.StatusCreated, "created", task)
+}
+
+func getTasks(w http.ResponseWriter, r *http.Request) {
+	taskList := make([]*Task, 0, len(tasks))
+	for _, t := range tasks {
+		taskList = append(taskList, t)
+	}
+	respondJSON(w, http.StatusOK, "success", taskList)
+}
+
+func respondJSON(w http.ResponseWriter, code int, msg string, data interface{}) {
+	w.Header().Set("Content-Type", "application/json")
+	w.WriteHeader(code)
+	json.NewEncoder(w).Encode(Response{Code: code, Message: msg, Data: data})
+}
+
+func respondError(w http.ResponseWriter, code int, msg string) {
+	respondJSON(w, code, msg, nil)
+}
+
+// 中间件
+func loggerMiddleware(next http.HandlerFunc) http.HandlerFunc {
+	return func(w http.ResponseWriter, r *http.Request) {
+		start := time.Now()
+		log.Printf("Started %s %s", r.Method, r.URL.Path)
+		next(w, r)
+		log.Printf("Completed %s %s in %v", r.Method, r.URL.Path, time.Since(start))
+	}
+}
+
+func recoveryMiddleware(next http.HandlerFunc) http.HandlerFunc {
+	return func(w http.ResponseWriter, r *http.Request) {
+		defer func() {
+			if err := recover(); err != nil {
+				log.Printf("Panic recovered: %v", err)
+				http.Error(w, "Internal Server Error", http.StatusInternalServerError)
+			}
+		}()
+		next(w, r)
+	}
+}
+
+func main() {
+	// 路由
+	http.HandleFunc("/tasks", recoveryMiddleware(loggerMiddleware(createTask)))
+	http.HandleFunc("/tasks", recoveryMiddleware(loggerMiddleware(getTasks)))
+
+	srv := &http.Server{
+		Addr:    ":8080",
+		Handler: nil, // 使用默认 ServeMux
+	}
+
+	// 启动服务器
+	go func() {
+		log.Println("Server starting on port 8080")
+		if err := srv.ListenAndServe(); err != nil && err != http.ErrServerClosed {
+			log.Fatal(err)
+		}
+	}()
+
+	// 优雅关闭
+	quit := make(chan os.Signal, 1)
+	signal.Notify(quit, syscall.SIGINT, syscall.SIGTERM)
+	<-quit
+	log.Println("Shutting down server...")
+
+	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
+	defer cancel()
+
+	if err := srv.Shutdown(ctx); err != nil {
+		log.Fatal("Server forced to shutdown:", err)
+	}
+
+	log.Println("Server exited")
+}