HTTP 201 Created vs 409 Conflict
HTTP 201 (Created) is a 2xx Success response, while 409 (Conflict) is a 4xx Client Error response. 201 indicates that the request succeeded and a new resource was created. Typically returned after POST or PUT requests that create a new entity. In contrast, 409 means that the request conflicts with the current state of the server. Often due to concurrent modification or business rule violations.
説明
The request succeeded and a new resource was created. Typically returned after POST or PUT requests that create a new entity.
このコードが表示される場合
After successfully creating a new user, post, order, or other resource via a REST API.
解決方法
No fix needed. Check the Location header for the URL of the new resource.
説明
The request conflicts with the current state of the server. Often due to concurrent modification or business rule violations.
このコードが表示される場合
When trying to create a resource that already exists, or updating a resource that was modified by another request.
解決方法
Refresh the resource state, resolve conflicts, and retry. Use ETags for optimistic concurrency.
主な違い
201 is a 2xx Success response, while 409 is a 4xx Client Error response.
HTTP 201: The request succeeded and a new resource was created. Typically returned after POST or PUT requests that create a new entity.
HTTP 409: The request conflicts with the current state of the server. Often due to concurrent modification or business rule violations.
You encounter 201 when after successfully creating a new user, post, order, or other resource via a REST API.
You encounter 409 when when trying to create a resource that already exists, or updating a resource that was modified by another request.
どちらをいつ使うか
For 201 (Created): No fix needed. Check the Location header for the URL of the new resource. For 409 (Conflict): Refresh the resource state, resolve conflicts, and retry. Use ETags for optimistic concurrency.