HTTP
501 Not Implemented レスポンスのモック
The server does not support the functionality required to fulfill the request. The server either does not recognize the request method or lacks the ability to fulfill it.
完全なリファレンスを見る →1 HTTP レスポンス
HTTP/1.1 501 Not Implemented
Content-Type: application/json
Date: Tue, 25 Feb 2026 12:00:00 GMT
Content-Length: 55
{
"error": "server_error",
"message": "Not Implemented"
}
2 curl でテストする
curl -i https://httpbin.org/status/501
3 フレームワークで 501 Not Implemented を返す
django
from django.http import JsonResponse
def my_view(request):
return JsonResponse(
{"error": "server_error", "message": "Not Implemented"},
status=501,
)
flask
from flask import Flask, jsonify
app = Flask(__name__)
@app.route("/endpoint")
def my_endpoint():
return jsonify({"error": "server_error", "message": "Not Implemented"}), 501
fastapi
from fastapi import FastAPI
from fastapi.responses import JSONResponse
app = FastAPI()
@app.get("/endpoint")
def my_endpoint():
return JSONResponse(
content={"error": "server_error", "message": "Not Implemented"},
status_code=501,
)
express.js
// Express.js
app.get('/endpoint', (req, res) => {
res.status(501).json({"error": "server_error", "message": "Not Implemented"});
});
spring boot
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.*;
import java.util.Map;
@RestController
public class MyController {
@GetMapping("/endpoint")
public ResponseEntity<Map<String, Object>> myEndpoint() {
return ResponseEntity
.status(501)
.body(Map.of("error", "not_implemented",
"message", "Not Implemented"));
}
}
go net/http
package main
import (
"encoding/json"
"net/http"
)
func myHandler(w http.ResponseWriter, r *http.Request) {
w.Header().Set("Content-Type", "application/json")
w.WriteHeader(501)
json.NewEncoder(w).Encode(map[string]string{
"error": "not_implemented",
"message": "Not Implemented",
})
}
ruby on rails
class MyController < ApplicationController
def my_action
render json: {"error": "server_error", "message": "Not Implemented"},
status: :not_implemented
end
end
asp.net core
// ASP.NET Core Minimal API
app.MapGet("/endpoint", () =>
Results.Json(
new { error = "not_implemented", message = "Not Implemented" },
statusCode: 501
)
);