go build_error ai_generated true

http: multiple registrations for /api/v1/users

ID: go/http-multiple-registrations

Also available as: JSON · Markdown · 中文
80%Fix Rate
88%Confidence
0Evidence
2024-05-10First Seen

Version Compatibility

VersionStatusIntroducedDeprecatedNotes
1.19 active — — —
1.22 active — — —

Root Cause

The same URL pattern is registered multiple times with http.Handle or http.HandleFunc, causing a panic.

generic

中文

相同的 URL 模式多次注册到 http.Handle 或 http.HandleFunc，导致 panic。

Workarounds

  1. 90% success 
    Check if pattern is already registered before adding: if _, exists := mux.Handlers()[pattern]; !exists { mux.Handle(pattern, handler) }
  2. 85% success 
    Use a single handler with method-based routing: http.HandleFunc("/api/v1/users", func(w http.ResponseWriter, r *http.Request) { switch r.Method { case "GET": ... case "POST": ... } })

Dead Ends

Common approaches that don't work:

  1. 100% fail

    Go panics on duplicate registration; this is not allowed.

  2. 50% fail

    Overriding can lead to unexpected behavior and is not idiomatic.