Golang在服务器运行时获取404

I am trying to run a basic web app, following a tutorial, using Golang and the routing package Gorilla/mux. The server is running fine but it refuses to find the index.html file regardless of what I put in the browser, always returning a 404.

Here is the code:

main.go

    package main

    import (
    "database/sql"
    "fmt"
    "net/http"

    "github.com/gorilla/mux"
    _ "github.com/lib/pq"
    )

    const (
    host     = "localhost"
    port     = 5432
    user     = "postgres"
    password = "0102"
    dbname   = "bird_encyclopaedia"
)

func newRouter() *mux.Router {
    r := mux.NewRouter()
    r.HandleFunc("/hello", handler).Methods("GET")


    staticFileDirectory := http.Dir("./assets/")
    staticFileHandler := http.StripPrefix("/assets/", http.FileServer(staticFileDirectory))
    r.PathPrefix("/assets/").Handler(staticFileHandler).Methods("GET")

    r.HandleFunc("/bird", getBirdHandler).Methods("GET")
    r.HandleFunc("/bird", createBirdHandler).Methods("POST")
    return r
}

func main() {
    fmt.Println("Starting server dickface...")
    connString := fmt.Sprintf("host=%s port=%d user=%s "+
        "password=%s dbname=%s sslmode=disable",
        host, port, user, password, dbname)
    db, err := sql.Open("postgres", connString)

    if err != nil {
        panic(err)
    }
    err = db.Ping()

    if err != nil {
        panic(err)
    }

    InitStore(&dbStore{db: db})

    r := newRouter()
    fmt.Println("Serving on port 8080")
    http.ListenAndServe(":8080", r)
}

func handler(w http.ResponseWriter, r *http.Request) {
    fmt.Fprintf(w, "Hello World!")
}

The html file is just in the assets/index.html directory, I can supply that if need be but I can't see the problem being in the actual html?

I have trawled through the code many times and cannot see why the server would not be able to find the directory. I have tried localhost/8080/assets, localhost/8080/assets/index.html, localhost/8080, and all other variants.

If I append it with /hello mind it returns the Hello world as seen in main.go And if I append it with /bird it returns "null" instead of 404.

You don't need http.StripPrefix() since you are not using the assets in the URL.

Just change these two lines:

staticFileHandler := http.StripPrefix("/assets/", http.FileServer(staticFileDirectory))
r.PathPrefix("/assets/").Handler(staticFileHandler).Methods("GET")

to

staticFileHandler := http.FileServer(staticFileDirectory)
r.PathPrefix("/").Handler(staticFileHandler).Methods("GET")