gweb总结之router

代码由此去

代码结构

.- router包 ├── middleware │ ├── param.go // 参数解析支持 │ ├── readme.md // 文档 │ ├── reqlog.go // 记录请求日志 │ ├── response.go // 响应的相关函数 │ └── safe.go // safe recover功能 └── router.go // 入口和request处理逻辑

整个router与gweb其他模块并不耦合&＃xff0c;只会依赖于logger。其中router.go是整个路由的入口的&＃xff0c;而middleware提供一些工具函数和简单的封装。

router处理逻辑

router.go 主要做了以下工作&＃xff1a;

定义路由&＃xff0c;及Controller注册
自定义http.Handler, 也就是ApiHandler&＃xff0c;实现ServeHTTP方法。

自定义路由Route

type Route struct {Path string // req URIMethod string // GET,POST...Fn interface{} // URI_METHOD hanlde FuncReqPool *sync.Pool // req form poolResPool *sync.Pool // response pool }

在使用的时候使用一个map[string][]*Route结构来存储URI和Method对应的路由处理函数。脑补一下&＃xff0c;实际的存储是这样的&＃xff1a;

{"/hello": [&Route{Path: "/hello",Method: "GET",Fn: someGetFunc,ReqPool: someGetReqPool,ResPool: someGetRespPool},&Route{Path: "/hello",Method: "POST",Fn: somePostFunc,ReqPool: somePostReqPool,ResPool: somePostRespPool},// ... more],// ... more }

用这样的结构主要是为了支持Restful API&＃xff0c;其他的暂时没有考虑

ApiHanlder

router.go 定义了一个ApiHandler如下&＃xff1a;

type ApiHandler struct {NotFound http.HandlerMethodNotAllowed http.Handler }

只是简单的包含了两个hander&＃xff0c;用于支持404和405请求。

&＃xff01;&＃xff01;&＃xff01;&＃xff01; 重点来了&＃xff0c;我们为什么要定一个那样的路由&＃xff1f;又怎么具体的解析参数&＃xff0c;响应&＃xff0c;处理请求呢&＃xff1f;Talk is Cheap, show me the Code

func (a *ApiHandler) ServeHTTP(w http.ResponseWriter, req *http.Request) {defer middleware.SafeHandler(w, req)path :&＃61; req.URL.Pathroute, ok :&＃61; foundRoute(path, req.Method)handle 404if !ok {if a.NotFound !&＃61; nil {a.NotFound.ServeHTTP(w, req)} else {http.NotFound(w, req)}return}// not nil and to, ref to foundRouteif route !&＃61; nil {goto Found}handle 405if !allowed(path, req.Method) {if a.MethodNotAllowed !&＃61; nil {a.MethodNotAllowed.ServeHTTP(w, req)} else {http.Error(w,http.StatusText(http.StatusMethodNotAllowed),http.StatusMethodNotAllowed,)}return}Found:normal handlereqRes :&＃61; route.ReqPool.Get()defer route.ReqPool.Put(reqRes)// parse paramsif errs :&＃61; middleware.ParseParams(w, req, reqRes); len(errs) !&＃61; 0 {je :&＃61; new(middleware.JsonErr)Response(je, NewCodeInfo(CodeParamInvalid, ""))je.Errs &＃61; errsmiddleware.ResponseErrorJson(w, je)return}in :&＃61; make([]reflect.Value, 1)in[0] &＃61; reflect.ValueOf(reqRes)Fn :&＃61; reflect.ValueOf(route.Fn)Call web server handle functionout :&＃61; Fn.Call(in)response to clientresp :&＃61; out[0].Interface()defer route.ResPool.Put(resp)middleware.ResponseJson(w, resp)return }

流程正如你所想的那样。处理405&＃xff0c;405等&＃xff0c;然后使用路由Route&＃xff0c;进行参数解析&＃xff0c;校验&＃xff0c;调用&＃xff0c;返回响应等操作。设计参照了httprouter。关于参数解析和响应&＃xff0c;马上就到。

参数解析和校验(param.go)

参数的解析&＃xff0c;一开始考虑的只有GET&＃xff0c;POST&＃xff0c;PUT&＃xff0c;DELETE 没有考虑JSON和文件的解析。因为一开始忙于搭框架是一方面&＃xff0c;其次因为我用的schema不支持&＃xff08;我也没仔细看&＃xff0c;自己实现起来也很简单&＃xff09;。

这里就推荐两个我常用的golang第三方库&＃xff0c;这也是我用于参数解析和校验的工具&＃xff1a;

schema, converts structs to and from form values.
beego/validation&＃xff0c;valid the struct

// ParseParams, parse params into reqRes from req.Form, and support // form-data, json-body // TODO: support parse file func ParseParams(w http.ResponseWriter, req *http.Request, reqRes interface{}) (errs ParamErrors) {switch req.Method {case http.MethodGet:req.ParseForm()case http.MethodPost, http.MethodPut:req.ParseMultipartForm(20 <<32)default:req.ParseForm()}// log requestlogReq(req)// if should parse Json body// parse json into reqResif shouldParseJson(reqRes) {data, err :&＃61; getJsonData(req)if err !&＃61; nil {errs &＃61; append(errs, NewParamError("parse.json", err.Error(), ""))return}if err &＃61; json.Unmarshal(data, reqRes); err !&＃61; nil {errs &＃61; append(errs, NewParamError("json.unmarshal", err.Error(), ""))return}bs, _ :&＃61; json.Marshal(reqRes)ReqL.Info("pasing json body: " &＃43; string(bs))goto Valid}// if has FILES field,// so parese req to get attachment filesif shouldParseFile(reqRes) {AppL.Info("should parse files")if req.MultipartForm &＃61;&＃61; nil || req.MultipartForm.File &＃61;&＃61; nil {errs &＃61; append(errs, NewParamError("FILES", "empty file param", ""))return}rv :&＃61; reflect.ValueOf(reqRes).Elem().FieldByName("FILES")// typ :&＃61; reflect.ValueOf(reqRes).Elem().FieldByName("FILES").Type()filesMap :&＃61; reflect.MakeMap(rv.Type())// parse file loopfor key, _ :&＃61; range req.MultipartForm.File {file, file_header, err :&＃61; req.FormFile(key)if err !&＃61; nil {errs &＃61; append(errs, NewParamError(Fstring("parse request.FormFile: %s", key),err.Error(), ""))}defer file.Close()filesMap.SetMapIndex(reflect.ValueOf(key),reflect.ValueOf(ParamFile{File: file,FileHeader: *file_header,}),)} // loop end// set value to reqRes.Field &＃96;FILES&＃96;rv.Set(filesMap)if len(errs) !&＃61; 0 {return}}// decodeif err :&＃61; decoder.Decode(reqRes, req.Form); err !&＃61; nil {errs &＃61; append(errs, NewParamError("decoder", err.Error(), ""))return}Valid:// validv :&＃61; poolValid.Get().(*valid.Validation)if ok, err :&＃61; v.Valid(reqRes); err !&＃61; nil {errs &＃61; append(errs, NewParamError("validation", err.Error(), ""))} else if !ok {for _, err :&＃61; range v.Errors {errs &＃61; append(errs, NewParamErrorFromValidError(err))}}return }

或许有人会关心shouldParseJson是怎么弄的&＃xff1f;如下:

// shouldParseJson check &＃96;i&＃96; has field &＃96;JSON&＃96; func shouldParseJson(i interface{}) bool {v :&＃61; reflect.ValueOf(i).Elem()if _, ok :&＃61; v.Type().FieldByName("JSON"); !ok {return false}return true }

这里强制设定了reqRes必须含有JSON字段&＃xff0c;才会解析jsonbody&＃xff1b;必须含有FILES才会解析请求中的文件。因此在写业务逻辑的时候&＃xff0c;要写成这个样子了,这些示例都在demo&＃xff1a;

/** JSON-Body Demo*/ type HelloJsonBodyForm struct {JSON bool &＃96;schema:"-" json:"-"&＃96; // 注意schema标签要设置“-”Name string &＃96;schema:"name" valid:"Required" json:"name"&＃96;Age int &＃96;schema:"age" valid:"Required;Min(0)" json:"age"&＃96; }var PoolHelloJsonBodyForm &＃61; &sync.Pool{New: func() interface{} { return &HelloJsonBodyForm{} }}type HelloJsonBodyResp struct {CodeInfoTip string &＃96;json:"tip"&＃96; }var PoolHelloJsonBodyResp &＃61; &sync.Pool{New: func() interface{} { return &HelloJsonBodyResp{} }}func HelloJsonBody(req *HelloJsonBodyForm) *HelloJsonBodyResp {resp :&＃61; PoolHelloJsonBodyResp.Get().(*HelloJsonBodyResp)defer PoolHelloJsonBodyResp.Put(resp)resp.Tip &＃61; fmt.Sprintf("JSON-Body Hello, %s! your age[%d] is valid to access", req.Name, req.Age)Response(resp, NewCodeInfo(CodeOk, ""))return resp }/** File Hanlder demo*/type HelloFileForm struct {FILES map[string]mw.ParamFile &＃96;schema:"-" json:"-"&＃96; // 注意schema标签设置“-”和FILES的type保持一直Name string &＃96;schema:"name" valid:"Required"&＃96;Age int &＃96;schema:"age" valid:"Required"&＃96; }var PoolHelloFileForm &＃61; &sync.Pool{New: func() interface{} { return &HelloFileForm{} }}type HelloFileResp struct {CodeInfoData struct {Tip string &＃96;json:"tip"&＃96;Name string &＃96;json:"name"&＃96;Age int &＃96;json:"age"&＃96;} &＃96;json:"data"&＃96; }var PoolHelloFileResp &＃61; &sync.Pool{New: func() interface{} { return &HelloFileResp{} }}func HelloFile(req *HelloFileForm) *HelloFileResp {resp :&＃61; PoolHelloFileResp.Get().(*HelloFileResp)defer PoolHelloFileResp.Put(resp)resp.Data.Tip &＃61; "foo"for key, paramFile :&＃61; range req.FILES {AppL.Infof("%s:%s\n", key, paramFile.FileHeader.Filename)s, _ :&＃61; bufio.NewReader(paramFile.File).ReadString(0)resp.Data.Tip &＃43;&＃61; s}resp.Data.Name &＃61; req.Nameresp.Data.Age &＃61; req.AgeResponse(resp, NewCodeInfo(CodeOk, ""))return resp }

响应(response.go)

gweb目的在于总结一个使用Json数据格式来进行交互的web服务结构。响应体设计如下&＃xff1a;

{"code": 0, // 错误码&＃xff0c;或许应该使用“error_code”, 不过不影响"message": "" // 错误消息"user": {"name": "yep",// ... other} }

结合上面的Demo&＃xff0c;大概看出来了&＃xff0c;响应并没什么花里胡哨的功能。只是需要将*resp使用json.Marshal转为字符串&＃xff0c;并发送给客户端就了事。

// ...Call web server handle functionout :&＃61; Fn.Call(in)response to clientresp :&＃61; out[0].Interface()defer route.ResPool.Put(resp)middleware.ResponseJson(w, resp)

路由到这里也就结束了&＃xff0c;虽然最重要&＃xff0c;但依然比较简单。