借“github.com/julienschmidt/httprouter“实践go mod

背景

执行如下代码，sublime找不到 “github.com/julienschmidt/httprouter”

package main

import (
    "fmt"
    "net/http"
    "log"
    "github.com/julienschmidt/httprouter"
)

func Index(w http.ResponseWriter, r *http.Request, _ httprouter.Params) {
    fmt.Fprint(w, "Welcome!
")
}

func Hello(w http.ResponseWriter, r *http.Request, ps httprouter.Params) {
    fmt.Fprintf(w, "hello, %s!
", ps.ByName("name"))
}

func main() {
    router := httprouter.New()
    router.GET("/", Index)
    router.GET("/hello/:name", Hello)

    log.Fatal(http.ListenAndServe(":8080", router))
}

解决办法

一、环境变量要对，这几个都要设 set GO111MODULE=on set GOBIN=E:go-workspacein set GOPATH=E:go-workspace set GOROOT=C:Program FilesGo

二、 用 go get -u github.com/julienschmidt/httprouter 在E:go-workspacepkgmod下拉取三方库 发现拉下来的是 github.com/julienschmidt/httprouter@v1.3.0 不是 github.com/julienschmidt/httprouter 查看E:go-workspacepkgmodgithub.comjulienschmidthttprouter@v1.3.0下的go mod 发现里面的内容又是 module github.com/julienschmidt/httprouter go 1.7 对不上啊

自己写的代码import一个带版本后缀的库，发现提示如下错误： imports github.com/julienschmidt/httprouter@v1.3.0: can only use path@version syntax with ‘go get’ and ‘go install’ in module-aware mode 自己写的代码import一个不带版本后缀的库，发现又提示库找不到，可怕

而且用go mod download github.com/julienschmidt/httprouter@v1.3.0拉，还只能拉有版本后缀的库！！！

解决办法： 将 httprouter@v1.3.0 目录改名叫 httprouter，同时重新 go mod init httprouter 和 go mod tidy 这样就对上了

最后在自己的项目目录下 /e/go-workspace/src/demo1 执行： go mod init demo1 go mod tidy

再次编译就OK了