Lecture 15: POST Method

REST API Development: Build, Test, Troubleshoot

The POST method is used in REST APIs to create new resources on the server. Unlike the GET method, which retrieves data, POST sends data from the client to the server so that a new record can be created.

POST requests typically include data in the request body, usually formatted as JSON. The server processes the data, performs validation, and stores the new resource in the database.

Purpose of the POST Method

The POST method allows clients to send new data to the server. This is commonly used when creating new records in a system.

Typical examples include:

• Creating a new product
• Registering a new user
• Adding a new order
• Submitting a form

Example POST Request

A POST request usually sends JSON data in the body of the request.

Request body:

This request asks the server to create a new product using the provided data.

Server Processing

When the server receives the POST request, it typically performs several steps:

• Validate the input data
• Create a new object based on the model
• Store the record in the database
• Return a response to the client

Example Response

If the operation is successful, the server may return a response like this:

The response often includes the newly created resource along with its generated identifier.

HTTP Status Codes for POST

• 201 Created – Resource successfully created
• 400 Bad Request – Invalid request data
• 500 Internal Server Error – Server processing error

Returning proper status codes helps clients understand the outcome of the request.

Testing POST Requests

POST requests can be tested using tools such as Postman. Developers can send JSON data in the request body and observe the API response.

Example endpoint tested in Postman:

Best Practices

• Validate input data before saving
• Return appropriate HTTP status codes
• Use clear JSON structures
• Ensure database operations are secure

Following these practices ensures that POST endpoints remain reliable and secure within REST API systems.

Next Steps

After implementing the POST method, the next step is to implement additional methods such as PUT and DELETE, allowing full CRUD functionality within the REST API.