HTTP Methods in Spring Boot – GET, POST, PUT, DELETE & PATCH Explained

Many beginners learn Spring Boot annotations and controllers but still feel confused about when to use GET, POST, PUT, DELETE, or PATCH. Once you clearly understand the purpose of each method, API design becomes logical and much easier.

This section explains HTTP methods in a simple, real-world, and beginner-friendly way, exactly how they are used in Spring Boot applications.



Why HTTP Methods Are Important

Each HTTP method has a specific responsibility. Using the correct method is not just a best practice—it is essential for building clean, secure, and professional APIs.

🔸 Helps maintain REST standards
🔸 Makes APIs easier to understand and consume
🔸 Improves code readability and long-term maintenance
🔸 Essential for real-world backend development

When APIs follow proper HTTP method usage, frontend developers, mobile developers, and other backend teams can integrate smoothly without confusion.

GET Request Handling

GET is used to retrieve data from the server. It is a read-only operation and must never change or modify any data.

In Spring Boot applications, GET requests are commonly used to fetch:

🔸 Lists of data
🔸 Single records
🔸 Read-only information
🔸 Used to fetch data
🔸 Safe and read-only
🔸 Parameters are usually sent in the URL
🔸 Can be tested easily using a browser

For example, fetching a list of users or viewing product details is a perfect use case for GET.

One important rule to remember:
GET requests should never be used to send sensitive information such as passwords or personal data, because the data appears in the URL and can be logged or cached.

POST Request Handling

POST is used to send data to the server and create new resources.

In Spring Boot, POST requests are commonly used for:

🔸 Saving form data
🔸 Creating new records
🔸 Submitting user input
🔸 Used to create new data
🔸 Data is sent in the request body
🔸 Not visible in the URL
🔸 Often used with JSON payloads

POST is the most common method when adding data to a database—for example, registering a new user or submitting an order.

Because POST sends data in the request body, it is more secure than GET for handling sensitive information.

PUT Request Handling

PUT is used to update an existing resource completely.

When a PUT request is sent, the server replaces the existing data with the new data provided in the request.

🔸 Used for full updates
🔸 Requires complete data
🔸 Replaces the existing resource
🔸 Ensures data consistency

For example, updating an entire user profile—name, email, phone, and address—can be handled using PUT.

PUT is useful when you want to make sure the server has the latest and complete version of the resource.

DELETE Request Handling

DELETE is used to remove data from the server.

In Spring Boot applications, DELETE requests are used to delete:

🔸 Records
🔸 Files
🔸 User data
🔸 Used to delete resources
🔸 Requires resource identification
🔸 Helps keep data clean and manageable
🔸 Should be handled carefully

DELETE operations must always include proper validation and authorization, because deleting data is irreversible in most systems.

For example, deleting a user account or removing a record from the database should only be allowed for authorized users.

PATCH Request Basics

PATCH is used to partially update a resource.

Unlike PUT, PATCH does not replace the entire object. Instead, it updates only the specific fields provided.

🔸 Used for partial updates
🔸 Updates only selected fields
🔸 More efficient than PUT in some cases
🔸 Useful for small changes

For example, updating only a user’s email or phone number is a good use case for PATCH.

PATCH is especially useful in modern applications where small, frequent updates are common.

Difference Between PUT and PATCH

Understanding the difference between PUT and PATCH is very important, especially for beginners.

🔸 PUT replaces the entire resource
🔸 PATCH updates only specific fields
🔸 PUT requires full data
🔸 PATCH requires partial data

Choosing the wrong method can lead to unexpected behavior or data loss. In real projects, teams clearly define when to use PUT and when to use PATCH.

Why Learning HTTP Methods Matters

HTTP methods are the foundation of REST APIs. Without understanding them, backend development becomes confusing and error-prone.

🔸 Required for Spring Boot development
🔸 Essential for backend and full-stack roles
🔸 Used in Android, web, and microservices
🔸 Important for interviews and real projects

A strong understanding of HTTP methods helps you design APIs that are clean, scalable, secure, and professional.

Once you master these basics, learning advanced topics like security, validation, and microservices becomes much easier.