Golang路由实现技巧 自定义多路复用器方案

http.Handler

ServeHTTP(ResponseWriter, *Request)

map[string]http.Handler

ServeHTTP

package main

import (
    "fmt"
    "net/http"
    "strings"
)

// 自定义路由器
type CustomRouter struct {
    routes map[string]http.Handler
}

// 创建新的自定义路由器
func NewCustomRouter() *CustomRouter {
    return &CustomRouter{
        routes: make(map[string]http.Handler),
    }
}

// 添加路由
func (cr *CustomRouter) AddRoute(path string, handler http.Handler) {
    cr.routes[path] = handler
}

// 实现 ServeHTTP 方法
func (cr *CustomRouter) ServeHTTP(w http.ResponseWriter, r *http.Request) {
    path := r.URL.Path

    // 查找匹配的路由
    handler, ok := cr.routes[path]
    if ok {
        handler.ServeHTTP(w, r)
        return
    }

    // 如果没有找到完全匹配的路由，尝试前缀匹配
    for routePath, routeHandler := range cr.routes {
        if strings.HasPrefix(path, routePath) {
            routeHandler.ServeHTTP(w, r)
            return
        }
    }

    // 如果没有找到匹配的路由，返回 404
    http.NotFound(w, r)
}

// 示例处理函数
func HomeHandler(w http.ResponseWriter, r *http.Request) {
    fmt.Fprintln(w, "Welcome to the home page!")
}

// 示例处理函数
func AboutHandler(w http.ResponseWriter, r *http.Request) {
    fmt.Fprintln(w, "This is the about page.")
}

func main() {
    // 创建自定义路由器
    router := NewCustomRouter()

    // 添加路由
    router.AddRoute("/", http.HandlerFunc(HomeHandler))
    router.AddRoute("/about", http.HandlerFunc(AboutHandler))
    router.AddRoute("/products/", http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
        fmt.Fprintln(w, "Products index")
    }))

    // 启动服务器
    server := &http.Server{
        Addr:    ":8080",
        Handler: router,
    }

    fmt.Println("Server listening on :8080")
    server.ListenAndServe()
}

ServeHTTP

/users/{id}

{id}

^/users/([0-9]+)$

type Route struct {
    Pattern *regexp.Regexp
    Handler http.Handler
    Params  []string // 参数名
}

// 添加带参数的路由
func (cr *CustomRouter) AddRouteWithParams(pattern string, handler http.Handler, params []string) {
    re := regexp.MustCompile(pattern)
    cr.routes[pattern] = &Route{Pattern: re, Handler: handler, Params: params} // 存储路由
}


// 修改 ServeHTTP 方法，处理参数
func (cr *CustomRouter) ServeHTTP(w http.ResponseWriter, r *http.Request) {
    path := r.URL.Path

    for routePath, routeHandler := range cr.routes {
        if route, ok := routeHandler.(*Route); ok { // 类型断言
            matches := route.Pattern.FindStringSubmatch(path)
            if len(matches) > 0 {
                // 提取参数
                params := make(map[string]string)
                for i, name := range route.Params {
                    if i+1 < len(matches) {
                        params[name] = matches[i+1]
                    }
                }
                // 将参数添加到请求上下文中 (需要自定义context)
                ctx := context.WithValue(r.Context(), "params", params)
                r = r.WithContext(ctx)

                route.Handler.ServeHTTP(w, r)
                return
            }
        } else {
            // ... (处理非参数路由)
        }
    }

    http.NotFound(w, r)
}

Middleware

http.Handler

http.Handler

Chain

http.Handler

Middleware

type Middleware func(http.Handler) http.Handler

func Chain(handler http.Handler, middlewares ...Middleware) http.Handler {
    for _, middleware := range middlewares {
        handler = middleware(handler)
    }
    return handler
}

// 示例中间件
func LoggingMiddleware(next http.Handler) http.Handler {
    return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
        fmt.Printf("Request: %s %s\n", r.Method, r.URL.Path)
        next.ServeHTTP(w, r)
    })
}

// 修改 AddRoute 方法，应用中间件
func (cr *CustomRouter) AddRoute(path string, handler http.Handler, middlewares ...Middleware) {
    cr.routes[path] = Chain(handler, middlewares...)
}

// 使用示例
router.AddRoute("/", http.HandlerFunc(HomeHandler), LoggingMiddleware)

http.HandleFunc

ServeHTTP

Method

func (cr *CustomRouter) ServeHTTP(w http.ResponseWriter, r *http.Request) {
    path := r.URL.Path
    method := r.Method

    handler, ok := cr.routes[path]
    if ok {
        // 检查HTTP方法
        if method == http.MethodGet { // 或者其他方法
            handler.ServeHTTP(w, r)
            return
        } else {
            http.Error(w, "Method Not Allowed", http.StatusMethodNotAllowed)
            return
        }
    }

    http.NotFound(w, r)
}

map[string]map[string]http.Handler

http.ServeMux

http.ServeMux