servlets http status codes

In Java Servlets, HTTP status codes are used to indicate the outcome of a client's request. When a client sends a request to a server, the server responds with an HTTP status code that indicates the status of the request. The HTTP status codes are 3-digit numbers that are grouped into 5 categories based on the first digit:

• 1xx: Informational - the request was received, continuing process
• 2xx: Success - the request was successfully received, understood, and accepted
• 3xx: Redirection - further action needs to be taken in order to complete the request
• 4xx: Client Error - the request contains bad syntax or cannot be fulfilled
• 5xx: Server Error - the server failed to fulfill an apparently valid request

Some of the commonly used HTTP status codes in Java Servlets include:

• 200 OK: The request was successful.
• 201 Created: The request was successful and a new resource was created.
• 204 No Content: The request was successful but there is no data to send back.
• 400 Bad Request: The request could not be understood or was missing required parameters.
• 401 Unauthorized: The request requires user authentication.
• 403 Forbidden: The server understood the request, but is refusing to fulfill it.
• 404 Not Found: The requested resource could not be found.
• 500 Internal Server Error: An error occurred on the server.
• 503 Service Unavailable: The server is currently unable to handle the request.

By using appropriate HTTP status codes, servlets can communicate the outcome of a client's request to the client in a standardized way. This can help clients understand what happened with their request and take appropriate action.