When building REST APIs, we often need to accept data in the request body, especially for operations like creating or updating resources. Without @RequestBody, we wouldn't be able to easily map the incoming request data to a Java object.
What is it?
@RequestBody is an annotation in Spring MVC used to bind the HTTP request body (typically in JSON or XML format) to a Java object. It helps in deserializing the incoming request data into a model object.
How is it used?
You use @RequestBody in a controller method to map the request data directly to the object parameter.
Example:
@PostMapping("/users") public String createUser(@RequestBody User user) { userService.saveUser(user); return "User created"; }
In this example, when a POST request is made to /users with a JSON payload like:
{ "name": "John", "email": "john@example.com" }
Spring will automatically convert the JSON data into a User object.
Key point:
- Ensure the request content-type is set to application/json for proper mapping.
@RequestBody makes it easier to handle incoming JSON or XML data in Spring applications.