public static String getAesKeyByConfig(Integer version) throws Exception {
        Properties properties = getApplicationProperties();
        Integer targetVersion = (version == null ? getCurrentVersion(properties) : version);
        if (StringUtils.isNotEmpty(AES_KEY_MAP.get(targetVersion))) {
            return AES_KEY_MAP.get(targetVersion);
        }

        // get aes key under specified version
        String keyName = CONFIG_ITEM_ENCRYPT_KEY_PREFIX + targetVersion;
        String aesKey = properties.getProperty(keyName);
        if (StringUtils.isEmpty(aesKey)) {
            throw new RuntimeException(String.format("cannot find encryption key %s in application config", keyName));
        }
        AES_KEY_MAP.put(targetVersion, aesKey);
        return aesKey;
    }
Get aes key from config file
inlong-manager/manager-common/src/main/java/org/apache/inlong/manager/common/util/AESUtils.java