Golang Web Framework Gin (part 1)

Gin is a Web framework written in Go (Golang).

To prepare

  • First you need to install Go (version 1.12+ required)

1. Install

  • Making the addresshttps://github.com/gin-gonic/gin

Create a directory called go-gin-test. Then CD goes to the directory

➜  mkdir go-gin-test
➜  cd go-gin-test 
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We use go Mod as package management for our project.

Initialize the go.mod file

go mod init example.com/m/v2
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Gin can be installed using the following Go command

go get -u github.com/gin-gonic/gin
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Seeing the following output proves that we have gin installed.

➜ go-gin-test go get -u github.com/gin-gonic/gin go: github.com/gin-gonic/gin upgrade => v1.6.3 go: Gopkg. In/yaml. V2 upgrade = > v2.4.0 go: github.com/golang/protobuf upgrade = > v1.5.2 go: github.com/modern-go/reflect2 upgrade => v1.0.1 go: github.com/modern-go/concurrent upgrade => v0.0.0-20180306012644-bacd9C7EF1DD go: Github.com/ugorji/go/codec upgrade = > v1.2.5 go: golang.org/x/sys upgrade = > v0.0.0-20210403161142-5 e06dd20ab57 go: github.com/go-playground/validator/v10 upgrade => v10.4.2 go: github.com/json-iterator/go upgrade => v1.1.10 go: Github.com/leodido/go-urn upgrade = > v1.2.1 go: downloading github.com/golang/protobuf v1.5.2 go: Downloading golang.org/x/sys v0.0.0-20210403161142-5 e06dd20ab57 go: Downloading github.com/go-playground/validator/v10 v10.4.2 go: downloading github.com/ugorji/go v1.2.5 go: Downloading google.golang.org/protobuf v1.26.0 go: downloading github.com/ugorji/go/codec v1.2.5 go: Golang.org/x/crypto upgrade = > v0.0.0-20210322153248-0 c34fe9e7dc2 go: google.golang.org/protobuf upgrade = > v1.26.0 go: Downloading golang.org/x/crypto v0.0.0 c34fe9e7dc2-20210322153248-0Copy the code

  • If go GET does not respond for a long time or times out, you are advised to use http://goproxy.cn/ to configure the domestic proxy

2. Hello World

Now let’s write our first Web application

➜ go-gin-test tree-l 3. ├── go. Mod ├─ goCopy the code

Our current directory structure is as shown above

The following

  • newmain.gofile
➜ go-gin- Test tree-l 3. ├── go. Mod ├── go. Sum ├── mianCopy the code

First let’s edit the main.go file

package main import "github.com/gin-gonic/gin" func main() { r := gin.Default() r.GET("/hello", func(c *gin.Context) { c.JSON(200, gin.H{ "message": "Hello world",})}) r.run () // Serve on 0.0.0.0:8080 (for Windows "localhost:8080")}Copy the code

Run go build -o Hello to compile as an executable

➜  go-gin-test go build -o hello
➜  go-gin-test ls
go.mod   go.sum   hello    mian.go
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Execute./hello to make our service run

➜ go-gin-test./hello [gin-debug] [WARNING] Creating an Engine instance with the Logger and Recovery middleware already attached. [GIN-debug] [WARNING] Running in "debug" mode. Switch to "release" mode in production. - using env: export GIN_MODE=release - using code: gin.SetMode(gin.ReleaseMode) [GIN-debug] GET /hello --> main.main.func1 (3 handlers) [GIN-debug] Environment variable PORT is undefined. Using port :8080 by default [GIN-debug] Listening and serving HTTP on :8080Copy the code

Open a browser check http://localhost:8080/hello

At this point, we have finished building our first Web service

3. Group and encapsulate routers

In actual production activities, business interfaces often need to be split into groups such as /user/XXX and/API /XXX. What should we do with GIN?

We continue with the above project for transformation

  • newrouterexfolder
  • newrouter.gofile
➜ go-gin-test tree -L 2. heavy Exercises ── heavy exercises ── heavy exercises ── heavy exercises ── heavy exercises ── heavy exercises ── heavy exercisesCopy the code

Edit the router.go file

Package RouterEx import "github.com/gin-gonic/gin" func InitRouter(g *gin.Engine) { http://localhost:8080/g1/hello1 g1 := g.Group("g1") g1.GET("/hello1", func(c *gin.Context) { c.JSON(200, gin.H{ "msg": "Hello g1",})}) http://localhost:8080/g1/hello1 g2 := g.Group("g2") g2.GET("/hello2", func(c *gin.Context) { c.JSON(200, gin.H{ "msg": "Hello g2", }) }) }Copy the code

Edit the main.go file

package main import ( "example.com/m/v2/routerex" "github.com/gin-gonic/gin" ) func main() { r := gin.Default() Routerex.initrouter (r) r.run () // Listen and serve on 0.0.0.0:8080 (for Windows "localhost:8080")}Copy the code

Do the same with go build -o Hello

Run./hello to start the service

Open a browser to check http://localhost:8080/g1/hello1 and http://localhost:8080/g2/hello2

You can see that we have split two different API groups. The registration mode of the router is encapsulated.

Try contacting the above methods

The next content preview:

  • Use of gin middleware
  • Different methods for obtaining parameters on the POST and GET interfaces
  • .

Students who want to obtain engineering can follow the superhero Jim, send gin in the public account, obtain engineering.

If you have any more information or suggestions, you can comment in the comments, or you can follow superhero Jim on my instagram, and I’ll get back to you as soon as I see it.