The go zero singleton service uses generics to simplify the registration of handler routes

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One 、Golang Environment installation and configuration Go Module

https://go-zero.dev/cn/docs/prepare/golang-install

mac OS install Go#

• Download and install Go for Mac
• Verify installation results

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|  | $ go version |
|  | go version go1.15.1 darwin/amd64 |

linux install Go#

• download Go for Linux
• Unzip the package to /usr/local

Copy Highlighter-hljs$ tar -C /usr/local -xzf go1.15.8.linux-amd64.tar.gz

• add to /usr/local/go/bin To environment variable

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|  | $ $HOME/.profile |
|  | $ export PATH=$PATH:/usr/local/go/bin |
|  | $ source $HOME/.profile |

• Verify installation results

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|  | $ go version |
|  | go version go1.15.1 linux/amd64 |

Windows install Go#

• Download and install Go for Windows
• Verify installation results

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|  | $ go version |
|  | go version go1.15.1 windows/amd64 |

MODULE To configure

Go Module yes Golang How to manage dependencies , image Java Medium Maven,Android Medium Gradle similar .

• see GO111MODULE Opening situation

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|  | $ go env GO111MODULE |
|  | on |

• Turn on GO111MODULE, If on （ The perform go env GO111MODULE The result is on） Please skip. .

Copy Highlighter-hljs$ go env -w GO111MODULE="on"

• Set up GOPROXY

Copy Highlighter-hljs$ go env -w GOPROXY=https://goproxy.cn

• Set up GOMODCACHE

Copy Highlighter-hljs see GOMODCACHE

$ go env GOMODCACHE

• If the directory is not empty or /dev/null, Please skip. .

Copy Highlighter-hljsgo env -w GOMODCACHE=$GOPATH/pkg/mod

Two 、Goctl install

Goctl stay go-zero Project development plays a great role , It can effectively help developers greatly improve development efficiency , Reduce the error rate of code , Reduce the workload of business development , added Goctl Please read the introduction of Goctl Introduce

• install (mac&linux)

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|  | ### Go 1.15  And previous versions  |
|  | GO111MODULE=on GOPROXY=https://goproxy.cn/,direct go get -u github.com/zeromicro/go-zero/tools/[email protected] |
|  |  |
|  | ### Go 1.16  And later versions  |
|  | GOPROXY=https://goproxy.cn/,direct go install github.com/zeromicro/go-zero/tools/[email protected] |

• install (windows)

Copy Highlighter-hljsgo install github.com/zeromicro/go-zero/tools/[email protected]

• Environment variable detection (mac&linux)
  go get Download the compiled binary file in $GOPATH/bin Under the table of contents , Make sure $GOPATH/bin Has been added to the environment variable .

Copy Highlighter-hljssudo vim /etc/paths // Add environment variables 

Add the following to the last line //$GOPATH It is the file address on your local computer

Copy Highlighter-hljs$GOPATH/bin 

• Verification of installation results

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|  | $ goctl -v |
|  | goctl version 1.1.4 darwin/amd64 |

Two 、 initialization go-zero

• Quickly generate api service

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|  | goctl api new greet |
|  | cd greet |
|  | go mod init |
|  | go mod tidy |
|  | go run greet.go -f etc/greet-api.yaml |

• Default listening is on 8888 port
  The listening port can be in greet-api.yaml Modify in the configuration file , here , Can pass curl request , Or open it directly in the browser http://localhost:8888/from/you

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|  | $ curl -i http://localhost:8888/from/you |
|  |  |
|  | HTTP/1.1 200 OK |
|  | Content-Type: application/json; charset=utf-8 |
|  | Traceparent: 00-45fa9e7a7c505bad3a53a024e425ace9-eb5787234cf3e308-00 |
|  | Date: Thu, 22 Oct 2020 14:03:18 GMT |
|  | Content-Length: 14 |
|  |  |
|  | null |

• greet Directory structure of the service

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|  | $ tree greet |
|  | greet |
|  | ├── etc |
|  | │ └── greet-api.yaml |
|  | ├── greet.api |
|  | ├── greet.go |
|  | └── internal |
|  |  ├── config |
|  |  │ └── config.go |
|  |  ├── handler |
|  |  │ ├── greethandler.go |
|  |  │ └── routes.go |
|  |  ├── logic |
|  |  │ └── greetlogic.go |
|  |  ├── svc |
|  |  │ └── servicecontext.go |
|  |  └── types |
|  |  └── types.go |

3、 ... and 、 View registration Handler Routing process

• greet.go

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|  | var configFile = flag.String("f", "etc/greet-api.yaml", "the config file") |
|  |  |
|  | func main() { |
|  |  flag.Parse() |
|  |  |
|  | var c config.Config |
|  |  conf.MustLoad(*configFile, &c) |
|  |  |
|  |  server := rest.MustNewServer(c.RestConf) |
|  | defer server.Stop() |
|  | // The above are loading configurations  |
|  |  ctx := svc.NewServiceContext(c) |
|  |  handler.RegisterHandlers(server, ctx) // This method is to register routes and route mappings Handler, That's the point  |
|  |  |
|  |  fmt.Printf("Starting server at %s:%d...\n", c.Host, c.Port) |
|  |  server.Start() |
|  | } |

• RegisterHandlers stay internal\handler\routes.go in

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|  | func RegisterHandlers(server *rest.Server, serverCtx *svc.ServiceContext) { |
|  |  server.AddRoutes( // Go to rest.Server Add route to  |
|  | []rest.Route{ // Route array  |
|  |  { |
|  |  Method: http.MethodGet, |
|  |  Path: "/from/:name", // route  |
|  |  Handler: GreetHandler(serverCtx),// Processing of current route Handler |
|  |  }, |
|  |  }, |
|  |  ) |
|  | } |

• GreetHandler stay internal\handler\greethandler.go in

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|  | func GreetHandler(ctx *svc.ServiceContext) http.HandlerFunc { |
|  | return func(w http.ResponseWriter, r *http.Request) { |
|  | 1. var req types.Request |
|  | 2. if err := httpx.Parse(r, &req); err != nil { // Wrong judgment of request , You don't have to worry about this  |
|  | 3. httpx.Error(w, err) |
|  | 4. return |
|  | 5. } |
|  |  |
|  |  l := logic.NewGreetLogic(r.Context(), ctx) //GreetHandler The handler forwarded the request to GreetLogic in , call NewGreetLogic Initialize the structure  |
|  |  resp, err := l.Greet(req) // And then call Greet To process requests , So we are GreetLogic.Greet You can see a sentence in the method // todo: add your logic here and delete this line |
|  | if err != nil { |
|  |  httpx.Error(w, err) |
|  |  } else { |
|  |  httpx.OkJson(w, resp) |
|  |  } |
|  |  } |
|  | } |

Four 、 Register for Handler Route simplification

Addition of project documents

During route registration , If we provide more services , So the corresponding func xxxxHandler(ctx *svc.ServiceContext) http.HandlerFunc It needs to be added many times , And inside the method body 1 To 5 Lines belong to additional repeated additions
for example ： Let's add a customlogic.go
According to the correctness and standardization of naming , Need to be in internal\logic Add under directory customlogic.go file , And then in internal\handler Add under directory customhandler.go file , And corresponding structures and functions are added to both files , Last in routes.go Add again in

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|  | { |
|  |  Method: http.MethodGet, |
|  |  Path: "/custom/:name", |
|  |  Handler: CustomHandler(serverCtx), |
|  | }, |

here , Our file structure should be like this

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|  | greet |
|  | ├── etc |
|  | │ └── greet-api.yaml |
|  | ├── greet.api |
|  | ├── greet.go |
|  | └── internal |
|  |  ├── config |
|  |  │ └── config.go |
|  |  ├── handler |
|  |  │ ├── greethandler.go |
|  |  │ ├── customhandler.go |
|  |  │ ├── ... |
|  |  │ └── routes.go |
|  |  ├── logic |
|  |  │ ├── greetlogic.go |
|  |  │ ├── ... |
|  |  │ └── customlogic.go |
|  |  ├── svc |
|  |  │ └── servicecontext.go |
|  |  └── types |
|  |  └── types.go |

When the monomer application reaches a certain order of magnitude ,handler and logic Many files will be added synchronously under the folder

Introduce the concept of generics

since Go1.18 Start ,go Start using generics , A broad definition of generics ： It's a special type that postpones the work of defining the type until the object is created or the method is called . In other words, in the process of using generics , The data type of the operation is specified as a parameter , And this parameter type can be used in class 、 Methods and interfaces in , They are called Generic classes 、 Generic methods 、 Generic interface .
We can use generics , Let it be fixed when adding routes Handler: GreetHandler(serverCtx) Put it off until later , According to the actual Logic Structure to judge what needs to be really executed logic.NewGreetLogic(r.Context(), ctx) Initialize structure and l.Greet(req) Logic processing method

How to do it

1. stay internal\logic Let's add one baselogic.go file , Reference resources Go Generic combat | How to use generics in structures

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|  | package logic |
|  |  |
|  | import ( |
|  | "greet/internal/svc" |
|  | "greet/internal/types" |
|  | "net/http" |
|  | ) |
|  |  |
|  | type BaseLogic interface { |
|  |  any |
|  |  Handler(req types.Request, w http.ResponseWriter, r *http.Request, svcCtx *svc.ServiceContext) // Each structure must inherit Handler Method , for example customlogic.go and greetlogic.go Medium Handler Method  |
|  | } |
|  |  |
|  | type logic[T BaseLogic] struct { |
|  |  data T |
|  | } |
|  |  |
|  | func New[T BaseLogic]() logic[T] { |
|  |  c := logic[T]{} |
|  | var ins T |
|  |  c.data = ins |
|  | return c |
|  | } |
|  | func (a *logic[T]) LogicHandler(req types.Request, w http.ResponseWriter, r *http.Request, svcCtx *svc.ServiceContext) { // As a transit processing method , Finally, execute the Handler |
|  |  a.data.Handler(req, w, r, svcCtx) |
|  | } |

2. take greethandler.go Document modified to basehandler.go, Comment out the previous GreetHandler Method

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|  | package handler |
|  |  |
|  | import ( |
|  | "net/http" |
|  |  |
|  | "greet/internal/logic" |
|  | "greet/internal/svc" |
|  | "greet/internal/types" |
|  |  |
|  | "github.com/zeromicro/go-zero/rest/httpx" |
|  | ) |
|  |  |
|  | // func GreetHandler(svcCtx *svc.ServiceContext) http.HandlerFunc { |
|  | // return BaseHandlerFunc(svcCtx) |
|  | // // return func(w http.ResponseWriter, r *http.Request) { |
|  | // // var req types.Request |
|  | // // if err := httpx.Parse(r, &req); err != nil { |
|  | // // httpx.Error(w, err) |
|  | // // return |
|  | // // } |
|  | // // l := logic.NewGreetLogic(r.Context(), svcCtx) |
|  | // // resp, err := l.Greet(&req) |
|  | // // if err != nil { |
|  | // // httpx.Error(w, err) |
|  | // // } else { |
|  | // // httpx.OkJson(w, resp) |
|  | // // } |
|  | // // } |
|  | // } |
|  |  |
|  | func BaseHandlerFunc[T logic.BaseLogic](svcCtx *svc.ServiceContext, t T) http.HandlerFunc { |
|  | return func(w http.ResponseWriter, r *http.Request) { |
|  | var req types.Request |
|  | if err := httpx.Parse(r, &req); err != nil { |
|  |  httpx.Error(w, err) |
|  | return |
|  |  } |
|  | // Dynamically call different structures through generics Handler Method  |
|  |  cc := logic.New[T]() |
|  |  cc.LogicHandler(req, w, r, svcCtx) |
|  |  } |
|  | } |

3. stay internal\logic\greetlogic.go Add one Handler Method

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|  | package logic |
|  |  |
|  | import ( |
|  | "context" |
|  | "net/http" |
|  |  |
|  | "greet/internal/svc" |
|  | "greet/internal/types" |
|  |  |
|  | "github.com/zeromicro/go-zero/core/logx" |
|  | "github.com/zeromicro/go-zero/rest/httpx" |
|  | ) |
|  |  |
|  | type GreetLogic struct { |
|  |  logx.Logger |
|  |  ctx context.Context |
|  |  svcCtx *svc.ServiceContext |
|  | } |
|  |  |
|  | func NewGreetLogic(ctx context.Context, svcCtx *svc.ServiceContext) *GreetLogic { |
|  | return &GreetLogic{ |
|  |  Logger: logx.WithContext(ctx), |
|  |  ctx: ctx, |
|  |  svcCtx: svcCtx, |
|  |  } |
|  | } |
|  | func (a GreetLogic) Handler(req types.Request, w http.ResponseWriter, r *http.Request, svcCtx *svc.ServiceContext) { // The new method  |
|  |  l := NewGreetLogic(r.Context(), svcCtx) |
|  |  resp, err := l.Greet(&req) |
|  | if err != nil { |
|  |  httpx.Error(w, err) |
|  |  } else { |
|  |  httpx.OkJson(w, resp) |
|  |  } |
|  | } |
|  |  |
|  | func (l *GreetLogic) Greet(req *types.Request) (resp *types.Response, err error) { |
|  | // todo: add your logic here and delete this line |
|  |  response := new(types.Response) |
|  | if (*req).Name == "me" { |
|  |  response.Message = "greetLogic: listen to me, thank you." |
|  |  } else { |
|  |  response.Message = "greetLogic: listen to you, thank me." |
|  |  } |
|  |  |
|  | return response, nil |
|  | } |

4. And then modify internal\handler\routes.go Below server.AddRoutes part

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|  | func RegisterHandlers(server *rest.Server, serverCtx *svc.ServiceContext) { |
|  |  server.AddRoutes( // Go to rest.Server Add route to  |
|  | []rest.Route{ // Route array  |
|  |  { |
|  |  Method: http.MethodGet, |
|  |  Path: "/from/:name", // route  |
|  |  Handler: BaseHandlerFunc(serverCtx,logic.GreetLogic{}), |
|  |  }, |
|  |  }, |
|  |  ) |
|  | } |

Now it's done , Let's start

Copy Highlighter-hljsgo run greet.go -f etc/greet-api.yaml

Then request it in the browser http://localhost:8888/from/you

Verify the new api route

1. stay internal\logic Next, add a new one customlogic.go file

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|  | package logic |
|  |  |
|  | import ( |
|  | "context" |
|  | "net/http" |
|  |  |
|  | "greet/internal/svc" |
|  | "greet/internal/types" |
|  |  |
|  | "github.com/zeromicro/go-zero/core/logx" |
|  | "github.com/zeromicro/go-zero/rest/httpx" |
|  | ) |
|  |  |
|  | type CustomLogic struct { |
|  |  logx.Logger |
|  |  ctx context.Context |
|  |  svcCtx *svc.ServiceContext |
|  | } |
|  |  |
|  | func NewCustomLogic(ctx context.Context, svcCtx *svc.ServiceContext) *CustomLogic { |
|  | return &CustomLogic{ |
|  |  Logger: logx.WithContext(ctx), |
|  |  ctx: ctx, |
|  |  svcCtx: svcCtx, |
|  |  } |
|  | } |
|  |  |
|  | func (a CustomLogic) Handler(req types.Request, w http.ResponseWriter, r *http.Request, svcCtx *svc.ServiceContext) { |
|  |  l := NewCustomLogic(r.Context(), svcCtx) |
|  |  resp, err := l.Custom(&req) |
|  | if err != nil { |
|  |  httpx.Error(w, err) |
|  |  } else { |
|  |  httpx.OkJson(w, resp) |
|  |  } |
|  | } |
|  |  |
|  | func (l *CustomLogic) Custom(req *types.Request) (resp *types.Response, err error) { //response.Message A little modification , Easy to distinguish  |
|  | // todo: add your logic here and delete this line |
|  |  response := new(types.Response) |
|  | if (*req).Name == "me" { |
|  |  response.Message = "customLogic: listen to me, thank you." |
|  |  } else { |
|  |  response.Message = "customLogic: listen to you, thank me." |
|  |  } |
|  |  |
|  | return response, nil |
|  | } |

2. And then modify internal\handler\routes.go

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|  | func RegisterHandlers(server *rest.Server, serverCtx *svc.ServiceContext) { |
|  |  server.AddRoutes( // Go to rest.Server Add route to  |
|  | []rest.Route{ // Route array  |
|  |  { |
|  |  Method: http.MethodGet, |
|  |  Path: "/from/:name", // route  |
|  |  Handler: BaseHandlerFunc(serverCtx,logic.GreetLogic{}), |
|  |  }, |
|  |  { |
|  |  Method: http.MethodGet, |
|  |  Path: "/to/:name", // route  |
|  |  Handler: BaseHandlerFunc(serverCtx,logic.CustomLogic{}), |
|  |  }, |
|  |  }, |
|  |  ) |
|  | } |

Other places don't need to be changed
Let's start

Copy Highlighter-hljsgo run greet.go -f etc/greet-api.yaml

Then request it in the browser http://localhost:8888/from/you、http://localhost:8888/to/you、http://localhost:8888/too/you

Now? , Adding a new logic When doing route mapping , You can simply add xxxxhandler.go The file , In fact, this Handler Moved to xxxxlogic.go in .

Novice , Don't like light spray

The code of this article is placed in