使用AOP技术对返回值进行解密处理，下面是示例代码：

统一返回值对象类：

public class Result {
    private int code;
    private String msg;
    private Object data;
    // 省略...
    // getter/setter...
}

自定义加解密类：

@Component
public class MyPasswordEncoder {
    private final String secret = "my_secret_key";

    // 加密
    public String encode(String str) {
        byte[] bytes = str.getBytes(StandardCharsets.UTF_8);
        byte[] key = secret.getBytes(StandardCharsets.UTF_8);
        SecretKeySpec secretKeySpec = new SecretKeySpec(key, "AES");
        try {
            Cipher cipher = Cipher.getInstance("AES");
            cipher.init(Cipher.ENCRYPT_MODE, secretKeySpec);
            byte[] result = cipher.doFinal(bytes);
            return Base64.getEncoder().encodeToString(result);
        } catch (Exception e) {
            throw new RuntimeException(e);
        }
    }

    // 解密
    public String decode(String str) {
        byte[] bytes = Base64.getDecoder().decode(str);
        byte[] key = secret.getBytes(StandardCharsets.UTF_8);
        SecretKeySpec secretKeySpec = new SecretKeySpec(key, "AES");
        try {
            Cipher cipher = Cipher.getInstance("AES");
            cipher.init(Cipher.DECRYPT_MODE, secretKeySpec);
            byte[] result = cipher.doFinal(bytes);
            return new String(result, StandardCharsets.UTF_8);
        } catch (Exception e) {
            throw new RuntimeException(e);
        }
    }
}

AOP切面类：

@Component
@Aspect
public class DecryptAspect {
    @Autowired
    private MyPasswordEncoder myPasswordEncoder;

    @Pointcut("execution(public * com.example.demo.controller..*.*(..))")
    public void decrypt() {
    }

    @Around("decrypt()")
    public Object doAround(ProceedingJoinPoint pjp) throws Throwable {
        Object[] args = pjp.getArgs();
        Object result = pjp.proceed(args); // 执行业务方法
        if (result instanceof Result) { // 判断返回值类型为Result
            Result r = (Result) result;
            Object data = r.getData();
            if (data instanceof String) { //