golang不到20行代码实现路由调度

项目地址

本项目依赖

使用标准库实现，无额外依赖

为什么需要路由调度层

golang http标准库只能精确匹配请求的URI，然后执行handler。现在一般web项目都至少有个Controller层，以struct实现，根据不同的请求路径派发到不同的方法中去。

路由调度器定义

Class.forName("xxx").newInstance()

routesaaction名称ccontroller名称controllerName*http.Requesthttp.ResponseWriter

由于golang的继承不是一般的OOP，所以也没有父子类这种说法，路由注册那里只能使用interface{}

代码实现

app/app.go

该文件为核心调度文件

package app

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

type application struct {
    routes map[string]interface{}
}

func New() *application {
    return &application{
        routes: make(map[string]interface{}),
    }
}

func (p *application) ServeHTTP(w http.ResponseWriter, r *http.Request) {
    controllerName := r.URL.Query().Get("c")
    actionName := r.URL.Query().Get("a")
    if controllerName == "" || actionName == "" {
        http.Error(w, http.StatusText(http.StatusBadRequest), http.StatusBadRequest)
        return
    }
    route, ok := p.routes[controllerName]
    if !ok {
        http.Error(w, "Controller Not Found", http.StatusNotFound)
        return
    }
    ele := reflect.ValueOf(route).Elem()
    ele.FieldByName("Request").Set(reflect.ValueOf(r))
    ele.FieldByName("Response").Set(reflect.ValueOf(w))
    ele.MethodByName(actionName).Call([]reflect.Value{})
}

func (p *application) printRoutes() {
    for route, controller := range p.routes {
        ele := reflect.ValueOf(controller).Type().String()
        fmt.Printf("%s %s\n", route, ele)
    }
}

func (p *application) Get(route string, controller interface{}) {
    p.routes[route] = controller
}

func (p *application) Run(addr string) error {
    p.printRoutes()
    fmt.Printf("listen on %s\n", addr)
    return http.ListenAndServe(addr, p)
}

app/controller.go

控制器"基类"

package app

import "net/http"

type Controller struct {
    Response http.ResponseWriter
    Request  *http.Request
}

controller/site.go

具体业务逻辑类

package controllers

import (
    "fmt"
    "app"
)

type SiteController struct {
    app.Controller
}

func (p SiteController) Index() {
    fmt.Fprint(p.Response, p.Request.RequestURI)
}

main.go

入口文件

package main

import (
    _ "github.com/go-sql-driver/mysql"
    "app"
    "controllers"
)

func main() {
    application := app.New()
    application.Get("site", &controllers.SiteController{})
    application.Run(":8080")
}

运行项目

http://localhost:8080?c=site&a=Index/?c=site&a=Index

写在最后

希望这个小小的项目能启发到各位读者，早日开发出适合自己的Web框架!