CORS是什么唐玩意

Server.go

 package main
 
 import (
-    "io"
-    "net/http"
+	"encoding/json"
+	"log"
+	"net/http"
+	"strconv"
+	"sync"
 )
 
-func Ping(w http.ResponseWriter, r *http.Request) {
-    io.WriteString(w, "pong~")
+// 统一响应格式
+type Response struct {
+	Code int         `json:"code"` // 0=成功, 非0=失败
+	Msg  string      `json:"msg"`  // 响应消息
+	Data interface{} `json:"data"` // 响应数据
+}
+
+// 评论数据结构
+type Comment struct {
+	ID      int    `json:"id"`      // 评论ID
+	Name    string `json:"name"`    // 评论者名字
+	Content string `json:"content"` // 评论内容
+}
+
+// 分页响应结构
+type CommentList struct {
+	Total    int       `json:"total"`    // 总评论数
+	Comments []Comment `json:"comments"` // 评论列表
+}
+
+var (
+	mutex     sync.RWMutex       // 读写锁保护共享数据
+	comments  []Comment          // 内存存储的评论列表
+	incrementID int = 1          // 自增ID计数器
+)
+
+// 发送统一格式的响应
+func sendResponse(w http.ResponseWriter, code int, msg string, data interface{}) {
+	w.Header().Set("Content-Type", "application/json")
+	resp := Response{
+		Code: code,
+		Msg:  msg,
+		Data: data,
+	}
+	json.NewEncoder(w).Encode(resp)
+}
+
+func respondOptions(w http.ResponseWriter) {
+	// 设置CORS头部
+	w.Header().Set("Access-Control-Allow-Origin", "*")
+	w.Header().Set("Access-Control-Allow-Methods", "GET, POST, OPTIONS")
+	w.Header().Set("Access-Control-Allow-Headers", "Content-Type")
+	w.WriteHeader(http.StatusOK)
+}
+
+// 获取评论处理函数
+func getCommentHandler(w http.ResponseWriter, r *http.Request) {
+
+	log.Printf("Received request: %s %s", r.Method, r.URL.Path)
+	// 提前处理 OPTIONS 请求
+	if r.Method == http.MethodOptions {
+		respondOptions(w)
+		return
+	}
+
+	// 只处理GET请求
+	if r.Method != http.MethodGet {
+		sendResponse(w, 1, "Method not allowed", nil)
+		return
+	}
+
+	// 解析查询参数
+	page, _ := strconv.Atoi(r.URL.Query().Get("page"))
+	size, _ := strconv.Atoi(r.URL.Query().Get("size"))
+
+	// 参数校验
+	if page < 1 {
+		page = 1
+	}
+	if size < 1 && size != -1 {
+		size = 10
+	}
+
+	mutex.RLock()         // 读锁定
+	defer mutex.RUnlock() // 函数返回时解锁
+
+	total := len(comments)
+
+	// 返回所有评论
+	if size == -1 {
+		sendResponse(w, 0, "success", CommentList{
+			Total:    total,
+			Comments: comments,
+		})
+		return
+	}
+
+	// 计算分页范围
+	start := (page - 1) * size
+	if start >= total {
+		sendResponse(w, 0, "success", CommentList{
+			Total:    total,
+			Comments: []Comment{},
+		})
+		return
+	}
+
+	end := start + size
+	if end > total {
+		end = total
+	}
+
+	// 返回分页数据
+	sendResponse(w, 0, "success", CommentList{
+		Total:    total,
+		Comments: comments[start:end],
+	})
+}
+
+// 添加评论处理函数
+func addCommentHandler(w http.ResponseWriter, r *http.Request) {
+	
+	// 输出Request信息到控制台：
+	log.Printf("Received request: %s %s", r.Method, r.URL.Path)
+	// 提前处理 OPTIONS 请求
+	if r.Method == http.MethodOptions {
+		respondOptions(w)
+		return
+	}
+
+
+	// 只处理POST请求
+	if r.Method != http.MethodPost {
+		sendResponse(w, 1, "Method not allowed", nil)
+		return
+	}
+
+	// 解析JSON请求体
+	var req struct {
+		Name    string `json:"name"`
+		Content string `json:"content"`
+	}
+	
+	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
+		sendResponse(w, 2, "Invalid request body", nil)
+		return
+	}
+
+	log.Printf("Received Info: Name=%s, Content=%s", req.Name, req.Content)
+
+	// 校验必要字段
+	if req.Name == "" || req.Content == "" {
+		sendResponse(w, 3, "Name and content are required", nil)
+		return
+	}
+
+	mutex.Lock()         // 写锁定
+	defer mutex.Unlock() // 函数返回时解锁
+
+	// 创建新评论
+	newComment := Comment{
+		ID:      incrementID,
+		Name:    req.Name,
+		Content: req.Content,
+	}
+	incrementID++
+
+	// 添加到内存存储
+	comments = append(comments, newComment)
+
+	// 返回新创建的评论
+	sendResponse(w, 0, "Comment added", newComment)
+}
+
+// 删除评论处理函数
+func deleteCommentHandler(w http.ResponseWriter, r *http.Request) {
+
+	log.Printf("Received request: %s %s", r.Method, r.URL.Path)
+	// 提前处理 OPTIONS 请求
+	if r.Method == http.MethodOptions {
+		respondOptions(w)
+		return
+	}
+
+	// 只处理POST请求
+	if r.Method != http.MethodPost {
+		sendResponse(w, 1, "Method not allowed", nil)
+		return
+	}
+
+	// 获取评论ID参数
+	idStr := r.URL.Query().Get("id")
+	if idStr == "" {
+		sendResponse(w, 4, "Missing id parameter", nil)
+		return
+	}
+
+	id, err := strconv.Atoi(idStr)
+	if err != nil {
+		sendResponse(w, 5, "Invalid id format", nil)
+		return
+	}
+
+	mutex.Lock()         // 写锁定
+	defer mutex.Unlock() // 函数返回时解锁
+
+	// 查找并删除评论
+	found := false
+	for i, comment := range comments {
+		if comment.ID == id {
+			// 从切片中删除元素
+			comments = append(comments[:i], comments[i+1:]...)
+			found = true
+			break
+		}
+	}
+
+	if !found {
+		sendResponse(w, 6, "Comment not found", nil)
+		return
+	}
+
+	sendResponse(w, 0, "Comment deleted", nil)
 }
 
 func main() {
-    http.HandleFunc("/ping", Ping)
-    http.ListenAndServe(":8080", nil)
+	// 初始化一些测试数据
+	comments = []Comment{
+		{ID: 1, Name: "Alice", Content: "First comment!"},
+		{ID: 2, Name: "Bob", Content: "Great work!"},
+	}
+	incrementID = 3
+
+	// 注册路由
+	http.HandleFunc("/comment/get", getCommentHandler)
+	http.HandleFunc("/comment/add", addCommentHandler)
+	http.HandleFunc("/comment/delete", deleteCommentHandler)
+
+	// 启动服务器
+	log.Println("Server starting on http://localhost:8080")
+	if err := http.ListenAndServe(":8080", nil); err != nil {
+		log.Fatal("Server failed to start: ", err)
+	}
 }
\ No newline at end of file