ResponseEntity in Spring Boot in Hindi | Handling HttpStatus while creating REST API

Summary

This tutorial explains how to handle HTTP status codes effectively in a Spring Boot application using ResponseEntity. It demonstrates how to send appropriate status codes (e.g., 200 for OK, 201 for Created, 404 for Not Found) with API responses to communicate the result of client requests. The video covers the importance of status codes for client-side decision-making, including various HTTP categories (2xx for success, 4xx for client errors, 5xx for server errors). The practical examples show how to implement these codes in GET, POST, DELETE, and PUT methods, enhancing API response handling in real-world applications.

Takeaways

• 😀 HTTP status codes are essential for understanding the result of an API request and communicating that result to the client.
• 😀 HTTP status codes are grouped into five categories based on their first digit: 1xx (Informational), 2xx (Successful), 3xx (Redirection), 4xx (Client Errors), and 5xx (Server Errors).
• 😀 Status code 200 means a successful request, while 201 indicates that a resource has been created.
• 😀 Status code 204 indicates successful completion of a request without returning data, useful for operations like deletions.
• 😀 Status codes starting with 4 indicate client errors, such as 400 (Bad Request), 401 (Unauthorized), and 403 (Forbidden).
• 😀 Status codes starting with 5 represent server errors, like 500 (Internal Server Error), 502 (Bad Gateway), and 503 (Service Unavailable).
• 😀 The Response Entity in Spring allows you to return custom HTTP status codes, headers, and body content along with the API response.
• 😀 Using Response Entity, developers can ensure the correct status code is sent for various operations, such as 404 (Not Found) for missing resources or 201 (Created) for successful creation.
• 😀 The Response Entity can handle different types of data like JSON, XML, or HTML, based on the API response's requirements.
• 😀 Properly implementing status codes, such as returning 200 for successful updates and 204 for deletions, improves client-server communication and helps in error handling.

Q & A

What is the purpose of using HTTP status codes in API responses?

HTTP status codes are used to convey information about the result or status of the requested operation. They allow the client to understand if the request was successfully processed or if there was an error, providing essential feedback before examining the response body.

What HTTP status code should be returned when a new resource is successfully created?

When a new resource is successfully created, the server should return a 201 HTTP status code, which indicates that the request has been fulfilled and a new resource has been created.

What is the difference between HTTP status codes 200, 201, and 204?

A 200 status code means the request was successfully processed and the requested resource is returned. A 201 indicates that a new resource has been created successfully, while a 204 means that the request was successful but there is no content to return, often used for deletion operations.

What HTTP status code should be used when a resource is not found?

When a resource is not found, the appropriate status code is 404 (Not Found), which indicates that the requested resource does not exist on the server.

Why would an API return a 400 HTTP status code?

A 400 status code (Bad Request) is returned when the client has made a request that is malformed or invalid. This could be due to missing parameters, incorrect syntax, or any other issue with the client's request.

What is the role of ResponseEntity in Spring?

ResponseEntity in Spring is a class used to customize the HTTP response. It allows developers to set the status, body, and headers of the response, and is particularly useful for returning different types of data such as JSON or XML in API responses.

What should be returned when a delete operation is successful but there is no content to return?

When a delete operation is successful but there is no content to return, a 204 (No Content) status code should be returned, indicating that the request was successful but there is no data in the response body.

What is the significance of using status codes starting with 3, like 301, 302, and 304?

Status codes starting with 3 indicate that further action is required to complete the request. A 301 indicates that the requested resource has been permanently moved to a different URL, 302 means the resource has been temporarily moved, and 304 means the client should use the cached version of the resource.

What should be done if an update request cannot find the resource to update?

If the resource to be updated cannot be found, the appropriate status code to return is 404 (Not Found), indicating that the resource does not exist and the update cannot be performed.

How can HTTP status codes be grouped and what do each group signify?

HTTP status codes are grouped into five categories based on their first digit. Codes starting with 1 are informational, 2 indicate successful requests, 3 mean further action is required, 4 indicate client errors, and 5 represent server errors.