Golang开源论坛新选择

这是一个很棒的Go语言学习项目！基于你的要求，我来分享一些纯标准库的实现建议和代码示例：

路由处理优化

使用http.ServeMux实现更清晰的路由结构：

// router.go
func setupRoutes() *http.ServeMux {
    mux := http.NewServeMux()
    
    mux.HandleFunc("/", homeHandler)
    mux.HandleFunc("/topic/", topicHandler)
    mux.HandleFunc("/user/", userHandler)
    mux.HandleFunc("/api/posts", apiPostsHandler)
    
    // 静态文件服务
    fs := http.FileServer(http.Dir("./static"))
    mux.Handle("/static/", http.StripPrefix("/static/", fs))
    
    return mux
}

// 中间件示例
func loggingMiddleware(next http.Handler) http.Handler {
    return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
        start := time.Now()
        next.ServeHTTP(w, r)
        log.Printf("%s %s %v", r.Method, r.URL.Path, time.Since(start))
    })
}

数据库操作封装

// db.go
type DB struct {
    *sql.DB
}

func NewDB(dataSourceName string) (*DB, error) {
    db, err := sql.Open("mysql", dataSourceName)
    if err != nil {
        return nil, err
    }
    
    if err := db.Ping(); err != nil {
        return nil, err
    }
    
    return &DB{db}, nil
}

// 帖子模型
type Post struct {
    ID        int       `json:"id"`
    Title     string    `json:"title"`
    Content   string    `json:"content"`
    AuthorID  int       `json:"author_id"`
    CreatedAt time.Time `json:"created_at"`
}

func (db *DB) CreatePost(post *Post) error {
    query := `INSERT INTO posts (title, content, author_id, created_at) 
              VALUES (?, ?, ?, ?)`
    result, err := db.Exec(query, post.Title, post.Content, post.AuthorID, time.Now())
    if err != nil {
        return err
    }
    
    id, err := result.LastInsertId()
    if err != nil {
        return err
    }
    
    post.ID = int(id)
    return nil
}

func (db *DB) GetPosts(limit, offset int) ([]Post, error) {
    query := `SELECT id, title, content, author_id, created_at 
              FROM posts ORDER BY created_at DESC LIMIT ? OFFSET ?`
    
    rows, err := db.Query(query, limit, offset)
    if err != nil {
        return nil, err
    }
    defer rows.Close()
    
    var posts []Post
    for rows.Next() {
        var post Post
        err := rows.Scan(&post.ID, &post.Title, &post.Content, &post.AuthorID, &post.CreatedAt)
        if err != nil {
            return nil, err
        }
        posts = append(posts, post)
    }
    
    return posts, nil
}

模板渲染增强

// template.go
type TemplateData struct {
    Title    string
    Posts    []Post
    User     *User
    Error    string
    Success  string
}

func renderTemplate(w http.ResponseWriter, tmpl string, data *TemplateData) error {
    templatePath := fmt.Sprintf("templates/%s.html", tmpl)
    baseTemplate := "templates/base.html"
    
    // 解析模板
    t, err := template.ParseFiles(baseTemplate, templatePath)
    if err != nil {
        http.Error(w, err.Error(), http.StatusInternalServerError)
        return err
    }
    
    // 设置默认标题
    if data.Title == "" {
        data.Title = "Go Discourse"
    }
    
    w.Header().Set("Content-Type", "text/html; charset=utf-8")
    return t.Execute(w, data)
}

// 使用示例
func homeHandler(w http.ResponseWriter, r *http.Request) {
    posts, err := db.GetPosts(10, 0)
    if err != nil {
        http.Error(w, err.Error(), http.StatusInternalServerError)
        return
    }
    
    data := &TemplateData{
        Title: "首页",
        Posts: posts,
    }
    
    if err := renderTemplate(w, "home", data); err != nil {
        log.Printf("模板渲染错误: %v", err)
    }
}

JSON API 响应

// api.go
type APIResponse struct {
    Success bool        `json:"success"`
    Data    interface{} `json:"data,omitempty"`
    Error   string      `json:"error,omitempty"`
}

func writeJSON(w http.ResponseWriter, status int, data interface{}) error {
    w.Header().Set("Content-Type", "application/json")
    w.WriteHeader(status)
    return json.NewEncoder(w).Encode(data)
}

func apiPostsHandler(w http.ResponseWriter, r *http.Request) {
    switch r.Method {
    case "GET":
        posts, err := db.GetPosts(20, 0)
        if err != nil {
            writeJSON(w, http.StatusInternalServerError, APIResponse{
                Success: false,
                Error:   "获取帖子失败",
            })
            return
        }
        
        writeJSON(w, http.StatusOK, APIResponse{
            Success: true,
            Data:    posts,
        })
        
    case "POST":
        var post Post
        if err := json.NewDecoder(r.Body).Decode(&post); err != nil {
            writeJSON(w, http.StatusBadRequest, APIResponse{
                Success: false,
                Error:   "无效的请求数据",
            })
            return
        }
        
        if err := db.CreatePost(&post); err != nil {
            writeJSON(w, http.StatusInternalServerError, APIResponse{
                Success: false,
                Error:   "创建帖子失败",
            })
            return
        }
        
        writeJSON(w, http.StatusCreated, APIResponse{
            Success: true,
            Data:    post,
        })
        
    default:
        writeJSON(w, http.StatusMethodNotAllowed, APIResponse{
            Success: false,
            Error:   "方法不允许",
        })
    }
}

主函数整合

// main.go
func main() {
    // 初始化数据库
    db, err := NewDB("user:password@/forum?parseTime=true")
    if err != nil {
        log.Fatal("数据库连接失败:", err)
    }
    defer db.Close()
    
    // 设置路由
    mux := setupRoutes()
    
    // 添加中间件
    handler := loggingMiddleware(mux)
    
    log.Println("服务器启动在 :8080")
    if err := http.ListenAndServe(":8080", handler); err != nil {
        log.Fatal("服务器启动失败:", err)
    }
}

这些代码展示了如何在不使用框架的情况下构建一个功能完整的论坛后端。项目结构清晰，易于扩展，完全符合你坚持使用标准库的学习目标。