go - 为什么这会在每个 URL 请求上得到服务？

Question

package main

import "fmt"
import "net/http"

func home(w http.ResponseWriter, r *http.Request) {
  fmt.Fprintf(w, "What!")
}

func bar(w http.ResponseWriter, r *http.Request) {
  fmt.Fprintf(w, "Bar!")
}

func main() {
  http.HandleFunc("/", home)
  http.HandleFunc("/foo", bar)
  http.ListenAndServe(":5678", nil)
}

如果我访问 /foo，bar 将运行。

如果我访问 / 或 /any/other/path，home 将运行。

知道为什么会这样吗？我该如何处理 404？

Answer 1

这是一种设计行为 - 为以 / 结尾的路径定义的处理程序也将处理任何子路径。

Note that since a pattern ending in a slash names a rooted subtree, the pattern "/" matches all paths not matched by other registered patterns, not just the URL with Path == "/".

http://golang.org/pkg/net/http/#ServeMux

您必须为 404 实现您自己的逻辑。考虑 golang 文档中的以下示例:

mux := http.NewServeMux()
mux.Handle("/api/", apiHandler{})
mux.HandleFunc("/", func(w http.ResponseWriter, req *http.Request) {
        // The "/" pattern matches everything, so we need to check
        // that we're at the root here.
        if req.URL.Path != "/" {
                http.NotFound(w, req)
                return
        }
        fmt.Fprintf(w, "Welcome to the home page!")
})

http://golang.org/pkg/net/http/#ServeMux.Handle