Selgitage HTTP protokoli idempotentsete meetodite mõistet ja nende tähtsust veebiteenuste jaoks.

HTTP idempotent methods are those methods that can be called multiple times in succession with the same result and without side effects after the first call. For example, if you send several identical requests, the server's state will not change after the first.

Classic idempotent methods are GET, PUT, DELETE, OPTIONS, and HEAD. For example, the PUT method is usually used to update a resource: if you send the same PUT request multiple times, the resource will have the same state.

The value of idempotency for web services:

• Allows safe repetition of requests in case of network errors or timeouts.
• Ensures predictable API behavior.
• Simplifies caching and request optimization.

Example:

PUT /users/123 HTTP/1.1
Content-Type: application/json

{"name": "Иван"}

If you send this request multiple times, the user with id 123 will have the name "Иван" — the state will not change after the first update.