diff --git a/zh/13.2.md b/zh/13.2.md index 775b0b58..822fa9b6 100644 --- a/zh/13.2.md +++ b/zh/13.2.md @@ -11,17 +11,17 @@ HTTP路由组件负责将HTTP请求交到对应的函数处理(或者是一个st 在3.4小节有过介绍Go的http包的详解，里面介绍了Go的http包如何设计和实现路由，这里继续以一个例子来说明： ```Go - func fooHandler(w http.ResponseWriter, r *http.Request) { - fmt.Fprintf(w, "Hello, %q", html.EscapeString(r.URL.Path)) - } +func fooHandler(w http.ResponseWriter, r *http.Request) { + fmt.Fprintf(w, "Hello, %q", html.EscapeString(r.URL.Path)) +} - http.HandleFunc("/foo", fooHandler) +http.HandleFunc("/foo", fooHandler) - http.HandleFunc("/bar", func(w http.ResponseWriter, r *http.Request) { - fmt.Fprintf(w, "Hello, %q", html.EscapeString(r.URL.Path)) - }) +http.HandleFunc("/bar", func(w http.ResponseWriter, r *http.Request) { + fmt.Fprintf(w, "Hello, %q", html.EscapeString(r.URL.Path)) +}) - log.Fatal(http.ListenAndServe(":8080", nil)) +log.Fatal(http.ListenAndServe(":8080", nil)) ``` 上面的例子调用了http默认的DefaultServeMux来添加路由，需要提供两个参数，第一个参数是希望用户访问此资源的URL路径(保存在r.URL.Path)，第二参数是即将要执行的函数，以提供用户访问的资源。路由的思路主要集中在两点： @@ -34,15 +34,15 @@ Go默认的路由添加是通过函数`http.Handle`和`http.HandleFunc`等来添 Go监听端口，然后接收到tcp连接会扔给Handler来处理，上面的例子默认nil即为`http.DefaultServeMux`，通过`DefaultServeMux.ServeHTTP`函数来进行调度，遍历之前存储的map路由信息，和用户访问的URL进行匹配，以查询对应注册的处理函数，这样就实现了上面所说的第二点。 ```Go - for k, v := range mux.m { - if !pathMatch(k, path) { - continue - } - if h == nil || len(k) > n { - n = len(k) - h = v.h - } +for k, v := range mux.m { + if !pathMatch(k, path) { + continue } + if h == nil || len(k) > n { + n = len(k) + h = v.h + } +} ``` ## beego框架路由实现 @@ -60,197 +60,197 @@ beego框架的路由器基于上面的几点限制考虑设计了一种REST方 根据上面的思路，我们设计了两个数据类型controllerInfo(保存路径和对应的struct，这里是一个reflect.Type类型)和ControllerRegistor(routers是一个slice用来保存用户添加的路由信息，以及beego框架的应用信息) ```Go - type controllerInfo struct { - regex *regexp.Regexp - params map[int]string - controllerType reflect.Type - } +type controllerInfo struct { + regex *regexp.Regexp + params map[int]string + controllerType reflect.Type +} + +type ControllerRegistor struct { + routers []*controllerInfo + Application *App +} - type ControllerRegistor struct { - routers []*controllerInfo - Application *App - } - ``` ControllerRegistor对外的接口函数有 ```Go - func (p *ControllerRegistor) Add(pattern string, c ControllerInterface) +func (p *ControllerRegistor) Add(pattern string, c ControllerInterface) ``` 详细的实现如下所示： ```Go - func (p *ControllerRegistor) Add(pattern string, c ControllerInterface) { - parts := strings.Split(pattern, "/") - - j := 0 - params := make(map[int]string) - for i, part := range parts { - if strings.HasPrefix(part, ":") { - expr := "([^/]+)" +func (p *ControllerRegistor) Add(pattern string, c ControllerInterface) { + parts := strings.Split(pattern, "/") - //a user may choose to override the defult expression - // similar to expressjs: ‘/user/:id([0-9]+)’ + j := 0 + params := make(map[int]string) + for i, part := range parts { + if strings.HasPrefix(part, ":") { + expr := "([^/]+)" + + //a user may choose to override the defult expression + // similar to expressjs: ‘/user/:id([0-9]+)’ - if index := strings.Index(part, "("); index != -1 { - expr = part[index:] - part = part[:index] - } - params[j] = part - parts[i] = expr - j++ + if index := strings.Index(part, "("); index != -1 { + expr = part[index:] + part = part[:index] } + params[j] = part + parts[i] = expr + j++ } - - //recreate the url pattern, with parameters replaced - //by regular expressions. then compile the regex - - pattern = strings.Join(parts, "/") - regex, regexErr := regexp.Compile(pattern) - if regexErr != nil { - - //TODO add error handling here to avoid panic - panic(regexErr) - return - } - - //now create the Route - t := reflect.Indirect(reflect.ValueOf(c)).Type() - route := &controllerInfo{} - route.regex = regex - route.params = params - route.controllerType = t - - p.routers = append(p.routers, route) - } + + //recreate the url pattern, with parameters replaced + //by regular expressions. then compile the regex + + pattern = strings.Join(parts, "/") + regex, regexErr := regexp.Compile(pattern) + if regexErr != nil { + + //TODO add error handling here to avoid panic + panic(regexErr) + return + } + + //now create the Route + t := reflect.Indirect(reflect.ValueOf(c)).Type() + route := &controllerInfo{} + route.regex = regex + route.params = params + route.controllerType = t + + p.routers = append(p.routers, route) + +} ``` ### 静态路由实现 上面我们实现的动态路由的实现，Go的http包默认支持静态文件处理FileServer，由于我们实现了自定义的路由器，那么静态文件也需要自己设定，beego的静态文件夹路径保存在全局变量StaticDir中，StaticDir是一个map类型，实现如下： ```Go - func (app *App) SetStaticPath(url string, path string) *App { - StaticDir[url] = path - return app - } +func (app *App) SetStaticPath(url string, path string) *App { + StaticDir[url] = path + return app +} ``` 应用中设置静态路径可以使用如下方式实现： ```Go - beego.SetStaticPath("/img","/static/img") - +beego.SetStaticPath("/img","/static/img") + ``` ### 转发路由 转发路由是基于ControllerRegistor里的路由信息来进行转发的，详细的实现如下代码所示： ```Go - // AutoRoute - func (p *ControllerRegistor) ServeHTTP(w http.ResponseWriter, r *http.Request) { - defer func() { - if err := recover(); err != nil { - if !RecoverPanic { - // go back to panic - panic(err) - } else { - Critical("Handler crashed with error", err) - for i := 1; ; i += 1 { - _, file, line, ok := runtime.Caller(i) - if !ok { - break - } - Critical(file, line) +// AutoRoute +func (p *ControllerRegistor) ServeHTTP(w http.ResponseWriter, r *http.Request) { + defer func() { + if err := recover(); err != nil { + if !RecoverPanic { + // go back to panic + panic(err) + } else { + Critical("Handler crashed with error", err) + for i := 1; ; i += 1 { + _, file, line, ok := runtime.Caller(i) + if !ok { + break } + Critical(file, line) } } - }() - var started bool - for prefix, staticDir := range StaticDir { - if strings.HasPrefix(r.URL.Path, prefix) { - file := staticDir + r.URL.Path[len(prefix):] - http.ServeFile(w, r, file) - started = true - return - } } - requestPath := r.URL.Path - - //find a matching Route - for _, route := range p.routers { - - //check if Route pattern matches url - if !route.regex.MatchString(requestPath) { - continue - } - - //get submatches (params) - matches := route.regex.FindStringSubmatch(requestPath) - - //double check that the Route matches the URL pattern. - if len(matches[0]) != len(requestPath) { - continue - } - - params := make(map[string]string) - if len(route.params) > 0 { - //add url parameters to the query param map - values := r.URL.Query() - for i, match := range matches[1:] { - values.Add(route.params[i], match) - params[route.params[i]] = match - } - - //reassemble query params and add to RawQuery - r.URL.RawQuery = url.Values(values).Encode() + "&" + r.URL.RawQuery - //r.URL.RawQuery = url.Values(values).Encode() - } - //Invoke the request handler - vc := reflect.New(route.controllerType) - init := vc.MethodByName("Init") - in := make([]reflect.Value, 2) - ct := &Context{ResponseWriter: w, Request: r, Params: params} - in[0] = reflect.ValueOf(ct) - in[1] = reflect.ValueOf(route.controllerType.Name()) - init.Call(in) - in = make([]reflect.Value, 0) - method := vc.MethodByName("Prepare") - method.Call(in) - if r.Method == "GET" { - method = vc.MethodByName("Get") - method.Call(in) - } else if r.Method == "POST" { - method = vc.MethodByName("Post") - method.Call(in) - } else if r.Method == "HEAD" { - method = vc.MethodByName("Head") - method.Call(in) - } else if r.Method == "DELETE" { - method = vc.MethodByName("Delete") - method.Call(in) - } else if r.Method == "PUT" { - method = vc.MethodByName("Put") - method.Call(in) - } else if r.Method == "PATCH" { - method = vc.MethodByName("Patch") - method.Call(in) - } else if r.Method == "OPTIONS" { - method = vc.MethodByName("Options") - method.Call(in) - } - if AutoRender { - method = vc.MethodByName("Render") - method.Call(in) - } - method = vc.MethodByName("Finish") - method.Call(in) + }() + var started bool + for prefix, staticDir := range StaticDir { + if strings.HasPrefix(r.URL.Path, prefix) { + file := staticDir + r.URL.Path[len(prefix):] + http.ServeFile(w, r, file) started = true - break - } - - //if no matches to url, throw a not found exception - if started == false { - http.NotFound(w, r) + return } } + requestPath := r.URL.Path + + //find a matching Route + for _, route := range p.routers { + + //check if Route pattern matches url + if !route.regex.MatchString(requestPath) { + continue + } + + //get submatches (params) + matches := route.regex.FindStringSubmatch(requestPath) + + //double check that the Route matches the URL pattern. + if len(matches[0]) != len(requestPath) { + continue + } + + params := make(map[string]string) + if len(route.params) > 0 { + //add url parameters to the query param map + values := r.URL.Query() + for i, match := range matches[1:] { + values.Add(route.params[i], match) + params[route.params[i]] = match + } + + //reassemble query params and add to RawQuery + r.URL.RawQuery = url.Values(values).Encode() + "&" + r.URL.RawQuery + //r.URL.RawQuery = url.Values(values).Encode() + } + //Invoke the request handler + vc := reflect.New(route.controllerType) + init := vc.MethodByName("Init") + in := make([]reflect.Value, 2) + ct := &Context{ResponseWriter: w, Request: r, Params: params} + in[0] = reflect.ValueOf(ct) + in[1] = reflect.ValueOf(route.controllerType.Name()) + init.Call(in) + in = make([]reflect.Value, 0) + method := vc.MethodByName("Prepare") + method.Call(in) + if r.Method == "GET" { + method = vc.MethodByName("Get") + method.Call(in) + } else if r.Method == "POST" { + method = vc.MethodByName("Post") + method.Call(in) + } else if r.Method == "HEAD" { + method = vc.MethodByName("Head") + method.Call(in) + } else if r.Method == "DELETE" { + method = vc.MethodByName("Delete") + method.Call(in) + } else if r.Method == "PUT" { + method = vc.MethodByName("Put") + method.Call(in) + } else if r.Method == "PATCH" { + method = vc.MethodByName("Patch") + method.Call(in) + } else if r.Method == "OPTIONS" { + method = vc.MethodByName("Options") + method.Call(in) + } + if AutoRender { + method = vc.MethodByName("Render") + method.Call(in) + } + method = vc.MethodByName("Finish") + method.Call(in) + started = true + break + } + + //if no matches to url, throw a not found exception + if started == false { + http.NotFound(w, r) + } +} ``` ### 使用入门 基于这样的路由设计之后就可以解决前面所说的三个限制点，使用的方式如下所示： @@ -258,17 +258,17 @@ ControllerRegistor对外的接口函数有 基本的使用注册路由： ```Go - beego.BeeApp.RegisterController("/", &controllers.MainController{}) +beego.BeeApp.RegisterController("/", &controllers.MainController{}) ``` 参数注册： ```Go - beego.BeeApp.RegisterController("/:param", &controllers.UserController{}) +beego.BeeApp.RegisterController("/:param", &controllers.UserController{}) ``` 正则匹配： ```Go - beego.BeeApp.RegisterController("/users/:uid([0-9]+)", &controllers.UserController{}) +beego.BeeApp.RegisterController("/users/:uid([0-9]+)", &controllers.UserController{}) ``` ## links * [目录]()