@RequestParam @RequestBody@PathVariable

@RequestParam, @RequestBody, and @PathVariable are three annotations used in Spring Framework for handling HTTP requests.

@RequestParam is used to extract parameters from the query string or form data in a request. It is used to bind the value of a query parameter to a method parameter in a Spring controller. For example, if a request contains a query parameter "name", we can use @RequestParam("name") annotation to bind the value of "name" parameter to a method parameter.

Example:

@GetMapping("/user")
public String getUser(@RequestParam("userId") String userId) {
// code to get user details using userId parameter
}

@RequestBody is used to extract the request body and bind it to a method parameter in a Spring controller. It is used when the request payload is in JSON or XML format. For example, if a request contains a JSON payload with user details, we can use @RequestBody annotation to map the JSON payload to a User object.

Example:

@PostMapping("/user")
public String createUser(@RequestBody User user) {
// code to create a new user using user object
}

@PathVariable is used to extract a variable value from the URL path and bind it to a method parameter in a Spring controller. It is used when a variable value is included in the URL path. For example, if the URL path is "/user/{userId}", we can use @PathVariable("userId") annotation to bind the value of "userId" variable to a method parameter.

Example:

@GetMapping("/user/{userId}")
public String getUserDetails(@PathVariable("userId") String userId) {
// code to get user details using userId parameter
}