我對(duì) Golang 還很陌生，正在嘗試制作一個(gè)簡(jiǎn)單的 REST api 應(yīng)用程序。最初，一切都很好，因?yàn)槲覍⑺写a都放在main包下的同一目錄中。但是，現(xiàn)在我處于需要開(kāi)始將代碼重構(gòu)為子目錄和包的階段。不幸的是，我未能成功編譯該應(yīng)用程序。我GOPATH的設(shè)置為：~/.workspace 當(dāng)前應(yīng)用程序位于：~/.workspace/src/gitlab.com/myapp/api-auth這是我目前的代碼組織方式：這是我的 main.gopackage mainimport (    "net/http"    "os"    "strings"    "github.com/gorilla/context"    "github.com/justinas/alice"    "gopkg.in/mgo.v2"    "gitlab.com/myapp/api-auth/middlewares")func main() {    privateKey := []byte(strings.Replace(os.Getenv("JWT_KEY"), "\\n", "\n", -1))    conn, err := mgo.Dial(os.Getenv("MONGO_CONN"))    if err != nil {        panic(err)    }    defer conn.Close()    conn.SetMode(mgo.Monotonic, true)    ctx := appContext{        conn.DB(os.Getenv("MONGO_DB")),        privateKey,    }    err = ctx.db.C("users").EnsureIndex(mgo.Index{        Key:        []string{"username"},        Unique:     true,        Background: true,        Sparse:     false,    })    if err != nil {        panic(err)    }    commonHandlers := alice.New(LoggingHandler, context.ClearHandler, RecoveryHandler, AcceptHandler, ContentTypeHandler)    router := NewRouter()    router.Post("/users", commonHandlers.Append(BodyParserHandler(UserResource{})).ThenFunc(ctx.userCreationHandler))    router.Post("/sessions", commonHandlers.Append(BodyParserHandler(UserResource{})).ThenFunc(ctx.sessionCreationHandler))    http.ListenAndServe(":8080", router)}type appContext struct {    db         *mgo.Database    privateKey []byte}這是中間件之一accept.go（其余中間件的構(gòu)造類(lèi)似）package middlewaresimport "net/http"// AcceptHandler ensures proper accept headers in requestsfunc AcceptHandler(next http.Handler) http.Handler {    fn := func(w http.ResponseWriter, r *http.Request) {        if r.Header.Get("Accept") != "application/vnd.api+json" {            writeError(w, errNotAcceptable)            return        }        next.ServeHTTP(w, r)    }    return http.HandlerFunc(fn)}