Data Binding, Validation

Data Binding, Validation

• Data Binding

  • @RequestParam

    @GetMapping("/search")
    public List<Item> searchItems(
        @RequestParam(name = "query") String query,
        @RequestParam(name = "page", required = false, defaultValue = "0") int page,
        @RequestParam(name = "size", required = false, defaultValue = "10") int size,
        @RequestParam(name = "sort", required = false, defaultValue = "asc") String sort) {
        return itemService.search(query, page, size, sort);
    }
    

  • @RequestBody

    @PostMapping("/users")
    public ResponseEntity<User> createUser(@RequestBody User user) {
        User createdUser = // Create user
        return ResponseEntity.status(HttpStatus.CREATED).body(createdUser);
    }
    

  • @PathVariable

    @DeleteMapping("/users/{id}")
    public ResponseEntity<Void> deleteUser(@PathVariable("id") Long id) {
        // Delete user
        return ResponseEntity.noContent().build();
    }
    

  • @RequestHeader

    @GetMapping("/headerDetails")
    public String headerDetails(@RequestHeader(name = "User-Agent") String userAgent) {
        return "User-Agent: " + userAgent;
    }
    

• Validation

  • Validating Request Body

    • @Valid with @RequestBody, and ****Validation Annotation on fields of POJO

    class User {
        @NotNull(message = "Name cannot be null")
        private String name;
    }
    
    @PostMapping("/users")
    public ResponseEntity<User> createUser(@Valid @RequestBody User user) {
        User createdUser = // Create user
        return ResponseEntity.status(HttpStatus.CREATED).body(createdUser);
    }
    

  • Validating Request Parameters, Path Variables, and Request Headers

    • @Validated with @RestController, and Validation Annotation on Request Parameters, Path Variables, or Request Headers

    @Validated
    @RestController
    public class UserController {
    
        @DeleteMapping("/users/{id}")
        public ResponseEntity<Void> deleteUser(@PathVariable("id") @Min(1) Long id) {
            // Delete user
            return ResponseEntity.noContent().build();
        }
    }
    

  • Validation Annotation

    • @NotNull
    • @NotBlank
    • @NotEmpty
    • @Min(value)
    • @Max(value)
    • @Email
    • @AssertTrue
    • @AssertFalse
    • @Null
    • @Size(min=val, max=val)
    • @Past
    • @Future

• ←Previous
• Next→