How do you handle different HTTP methods (GET, POST, PUT, DELETE) in Spring Boot?

Table of Contents

• Introduction
• Handling HTTP Methods in Spring Boot
  • 1. GET Method: Fetch Data
    • Example: Handling GET Requests with @GetMapping
  • 2. POST Method: Create Data
    • Example: Handling POST Requests with @PostMapping
  • 3. PUT Method: Update Data
    • Example: Handling PUT Requests with @PutMapping
  • 4. DELETE Method: Delete Data
    • Example: Handling DELETE Requests with @DeleteMapping
• Practical Example: Full CRUD Operations
• Conclusion

Introduction

In Spring Boot, handling various HTTP methods (GET, POST, PUT, DELETE) is fundamental for building RESTful APIs. Each HTTP method corresponds to a specific CRUD (Create, Read, Update, Delete) operation. These methods are mapped to handler methods in your Spring controllers using specific annotations such as @GetMapping, @PostMapping, @PutMapping, and @DeleteMapping. These annotations make it simple to map HTTP requests to Java methods that process them.

In this guide, we'll explore how to handle these HTTP methods in Spring Boot and provide practical examples.

Handling HTTP Methods in Spring Boot

1. GET Method: Fetch Data

The GET method is used to retrieve data from the server. It is commonly used to fetch resources or information without modifying the server state.

Example: Handling GET Requests with @GetMapping

• @GetMapping maps HTTP GET requests to the getUserById method.
• @PathVariable is used to bind the URL parameter (id) to the method parameter.

Sample Request:
GET /users/1

Sample Response:

2. POST Method: Create Data

The POST method is used to send data to the server to create a new resource.

Example: Handling POST Requests with @PostMapping

• @PostMapping maps HTTP POST requests to the createUser method.
• @RequestBody binds the incoming request body to the user object.
• @Valid triggers validation for the User object.

Sample Request:
POST /users/create

Sample Response:

3. PUT Method: Update Data

The PUT method is used to update an existing resource on the server. It typically replaces the entire resource.

Example: Handling PUT Requests with @PutMapping

• @PutMapping maps HTTP PUT requests to the updateUser method.
• @PathVariable binds the URL parameter (id) to the method parameter.
• @RequestBody binds the request body to the user object.

Sample Request:
PUT /users/1

Sample Response:

4. DELETE Method: Delete Data

The DELETE method is used to remove a resource from the server.

Example: Handling DELETE Requests with @DeleteMapping

• @DeleteMapping maps HTTP DELETE requests to the deleteUser method.
• @PathVariable binds the URL parameter (id) to the method parameter.

Sample Request:
DELETE /users/1

Sample Response:
HTTP 204 No Content

Practical Example: Full CRUD Operations

Conclusion

Handling different HTTP methods (GET, POST, PUT, DELETE) in Spring Boot is crucial for building RESTful APIs. Each HTTP method serves a distinct purpose:

• GET for fetching resources
• POST for creating new resources
• PUT for updating resources
• DELETE for removing resources

By using the corresponding Spring annotations (@GetMapping, @PostMapping, @PutMapping, and @DeleteMapping), developers can easily implement these methods in their Spring Boot controllers. Proper error handling and response management ensure that the API remains efficient and user-friendly.