데이터 보호를 위한 어노테이션 기반 필드 암호화 처리 방안을 제시합니다. AOP를 활용한 구현 구조는 다음과 같습니다.

의존성 추가

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-aop</artifactId>
</dependency>
<dependency>
    <groupId>cn.hutool</groupId>
    <artifactId>hutool-all</artifactId>
</dependency>

도메인 객체 구성

public class SecureData {
    @Decrypt
    private String securedContent;
    
    private List<SecureItem> items;
}

public class SecureItem {
    @Decrypt
    private String protectedText;
    
    @Encrypt
    private String sensitiveData;
}

암호화 어노테이션 정의

@Target(ElementType.FIELD)
@Retention(RetentionPolicy.RUNTIME)
public @interface Encrypt {}

@Target(ElementType.FIELD)
@Retention(RetentionPolicy.RUNTIME)
public @interface Decrypt {}

암호화 핵심 처리기

public class CryptoProcessor {
    private CryptoAdapter cryptoAdapter = new Base64Adapter();
    private static final List<Class<?>> IGNORE_TYPES = Arrays.asList(Date.class, Number.class);
    
    public void process(Object target, boolean isDecrypt) {
        if (target == null) return;
        
        if (target instanceof List) {
            processCollection((List<?>) target, isDecrypt);
        } else {
            processObject(target, isDecrypt);
        }
    }
    
    private void processObject(Object obj, boolean isDecrypt) throws Exception {
        for (Field field : obj.getClass().getDeclaredFields()) {
            field.setAccessible(true);
            Object value = field.get(obj);
            
            if (value instanceof String && field.isAnnotationPresent(Encrypt.class)) {
                if (!isDecrypt) field.set(obj, cryptoAdapter.encrypt((String) value));
            }
            // 복호화 로직 생략
        }
    }
}

암호화 알고리즘 인터페이스

public interface CryptoAdapter {
    String encrypt(String plainText);
    String decrypt(String cipherText);
}

public class AESAdapter implements CryptoAdapter {
    private SecretKeySpec secretKey;
    
    public String encrypt(String text) {
        Cipher cipher = Cipher.getInstance("AES");
        cipher.init(Cipher.ENCRYPT_MODE, secretKey);
        return Base64.getEncoder().encodeToString(cipher.doFinal(text.getBytes()));
    }
    // 복호화 구현 생략
}

AOP 통합 처리

@Aspect
@Component
public class CryptoAspect {
    @Around("execution(* com.example..controller.*.*(..))")
    public Object handleCrypto(ProceedingJoinPoint pjp) throws Throwable {
        Object[] args = pjp.getArgs();
        new CryptoProcessor().process(args, true);
        Object result = pjp.proceed();
        new CryptoProcessor().process(result, false);
        return result;
    }
}

컨트롤러 테스트

@RestController
public class DemoController {
    @PostMapping("/secure")
    public SecureData process(@RequestBody SecureData data) {
        return data;
    }
}

입력값 전달 시 @Encrypt/@Decrypt 어노테이션이 적용된 필드는 자동으로 암복호화 처리됩니다.