Spring Boot常用的参数验证技巧和使用方法

@RestController
public class UserController {
    @PostMapping("/user")
    public ResponseEntity<String> createUser(@Valid @RequestBody UserRequest request) {
        // 处理请求
        return ResponseEntity.ok("User created successfully");
    }
}

public class UserRequest {
    @NotBlank(message = "用户名不能为空")
    private String username;
    @Size(min = 6, max = 12, message = "密码长度必须在6到12个字符之间")
    private String password;
    // getter 和 setter 方法省略
}

@Component
public class AgeValidator implements ConstraintValidator<ValidAge, Integer> {
    @Override
    public boolean isValid(Integer age, ConstraintValidatorContext context) {
        // 实现自定义的验证逻辑
        return age >= 18 && age <= 60;
    }
}

@RestController
public class UserController {
    @PostMapping("/user")
    public ResponseEntity<String> createUser(@ValidAge @RequestParam("age") Integer age) {
        // 处理请求
        return ResponseEntity.ok("User created successfully");
    }
}

@ControllerAdvice
public class GlobalExceptionHandler {
    @ExceptionHandler(MethodArgumentNotValidException.class)
    public ResponseEntity<String> handleMethodArgumentNotValid(MethodArgumentNotValidException ex) {
        BindingResult result = ex.getBindingResult();
        List<ObjectError> errors = result.getAllErrors();
        StringBuilder errorMessage = new StringBuilder();
        for (ObjectError error : errors) {
            errorMessage.append(error.getDefaultMessage()).append("; ");
        }
        return ResponseEntity.badRequest().body(errorMessage.toString());
    }
}