Input-Related Annotations for Spring APIs

@RequestBody

• Description: Binds the body of an HTTP request to a Java object, typically used in POST or PUT requests.
• Example:

  @PostMapping("/add")
  public ResponseEntity addEntity(@RequestBody MyEntity entity) {
    // logic
  }
   

@RequestParam

• Description: Extracts query parameters from the URL.
• Example:

   @GetMapping("/search")
   public ResponseEntity search(@RequestParam String query) {
      // logic
    }   

@PathVariable

• Description: Captures values from the URI path and binds them to method parameters.
• Example :

@GetMapping("/items/{id}")
public ResponseEntity getItem(@PathVariable Long id) {
  // logic
}

@Validated

• Description: Enables validation for a method parameter or bean, used in combination with validation annotations like @NotNull, @Size, etc.
• Example:

 @PostMapping("/submit")
 public ResponseEntity submit(@Validated @RequestBody MyEntity entity) {
     // logic
 } 

@Valid

• Description: Triggers validation for the annotated object, typically a request body.
• Example:

@PostMapping("/create")
public ResponseEntity createEntity(@Valid @RequestBody MyEntity entity) {
      // logic
}   

@ModelAttribute

• Description: Binds request parameters to a model object, commonly used in forms.
• Example:

@PostMapping("/form")
public String submitForm(@ModelAttribute UserForm form) {
    // logic
}     

@CookieValue

• Description: Binds HTTP cookie values to a method parameter.
• Example:

@GetMapping("/get-cookie")>  
public String getCookieValue(@CookieValue String sessionId) {
    // logic
}