c++ Json.hpp 应用
作者：互联网
上位参照
https://blog.csdn.net/baidu_33879812/article/details/107559843
json.hpp是一个非常强大的工具，只需要包含这个头文件，即可对json文件进行操作。
Git地址：https://github.com/nlohmann/json
Git上有简单的使用说明，简书这位作者已经将其汉化。
详见：https://www.jianshu.com/p/69e57f2af904?tdsourcetag=s_pctim_aiomsg
来源：鸿蒙代码
bool InnerBundleInfo::FromJson(const nlohmann::json &jsonObject)
{
try {
isSupportBackup_ = jsonObject.at(IS_SUPPORT_BACKUP).get<bool>();
appType_ = jsonObject.at(APP_TYPE).get<Constants::AppType>();
uid_ = jsonObject.at(UID).get<int>();
gid_ = jsonObject.at(GID).get<int>();
baseDataDir_ = jsonObject.at(BASE_DATA_DIR).get<std::string>();
bundleStatus_ = jsonObject.at(BUNDLE_STATUS).get<BundleStatus>();
baseBundleInfo_ = jsonObject.at(BASE_BUNDLE_INFO).get<BundleInfo>();
baseApplicationInfo_ = jsonObject.at(BASE_APPLICATION_INFO).get<ApplicationInfo>();
baseAbilityInfos_ = jsonObject.at(BASE_ABILITY_INFO).get<std::map<std::string, AbilityInfo>>();
innerModuleInfos_ = jsonObject.at(INNER_MODULE_INFO).get<std::map<std::string, InnerModuleInfo>>();
skillInfos_ = jsonObject.at(SKILL_INFOS).get<std::map<std::string, std::vector<Skill>>>();
isKeepData_ = jsonObject.at(IS_KEEP_DATA).get<bool>();
userId_ = jsonObject.at(USER_ID).get<int>();
mainAbility_ = jsonObject.at(MAIN_ABILITY).get<std::string>();
provisionId_ = jsonObject.at(PROVISION_ID).get<std::string>();
appFeature_ = jsonObject.at(APP_FEATURE).get<std::string>();
hasEntry_ = jsonObject.at(HAS_ENTRY).get<bool>();
} catch (nlohmann::detail::parse_error &exception) {
APP_LOGE("has a parse_error:%{public}s", exception.what());
return false;
} catch (nlohmann::detail::type_error &exception) {
APP_LOGE("has a type_error:%{public}s.", exception.what());
return false;
} catch (nlohmann::detail::out_of_range &exception) {
APP_LOGE("has an out_of_range exception:%{public}s.", exception.what());
return false;
}
return true;
}
void InnerBundleInfo::ToJson(nlohmann::json &jsonObject) const
{
jsonObject[IS_SUPPORT_BACKUP] = isSupportBackup_;
jsonObject[APP_TYPE] = appType_;
jsonObject[UID] = uid_;
jsonObject[GID] = gid_;
jsonObject[BASE_DATA_DIR] = baseDataDir_;
jsonObject[BUNDLE_STATUS] = bundleStatus_;
jsonObject[BASE_APPLICATION_INFO] = baseApplicationInfo_;
jsonObject[BASE_BUNDLE_INFO] = baseBundleInfo_;
jsonObject[BASE_ABILITY_INFO] = baseAbilityInfos_;
jsonObject[INNER_MODULE_INFO] = innerModuleInfos_;
jsonObject[SKILL_INFOS] = skillInfos_;
jsonObject[IS_KEEP_DATA] = isKeepData_;
jsonObject[USER_ID] = userId_;
jsonObject[MAIN_ABILITY] = mainAbility_;
jsonObject[PROVISION_ID] = provisionId_;
jsonObject[APP_FEATURE] = appFeature_;
jsonObject[HAS_ENTRY] = hasEntry_;
}
bool BundleDataStorage::LoadAllData(std::map<std::string, std::map<std::string, InnerBundleInfo>> &infos) const
{
bool ret = false;
APP_LOGI("load all installed bundle data to map");
std::fstream i(Constants::BUNDLE_DATA_BASE_FILE);
nlohmann::json jParse;
if (!i.is_open()) {
APP_LOGE("failed to open bundle database file");
// if file not exist, should create file here
std::ofstream o(Constants::BUNDLE_DATA_BASE_FILE);
o.close();
return false;
}
APP_LOGI("open bundle database file success");
i.seekg(0, std::ios::end);
int len = static_cast<int>(i.tellg());
if (len > 0) {
i.seekg(0, std::ios::beg);
i >> jParse;
for (auto &app : jParse.items()) {
std::map<std::string, InnerBundleInfo> deviceMap;
for (auto &device : app.value().items()) {
InnerBundleInfo innerBundleInfo;
ret = innerBundleInfo.FromJson(device.value());
deviceMap.emplace(device.key(), innerBundleInfo);
}
auto pair = infos.emplace(app.key(), deviceMap);
ret = pair.second;
}
}
i.close();
return ret;
}
bool BundleDataStorage::SaveStorageBundleInfo(const std::string &deviceId, const InnerBundleInfo &innerBundleInfo) const
{
APP_LOGI("save bundle data");
bool ret = true;
std::string appName = innerBundleInfo.GetApplicationName();
std::fstream f(Constants::BUNDLE_DATA_BASE_FILE);
bool isExist = f.good();
if (isExist) {
nlohmann::json innerInfo;
innerBundleInfo.ToJson(innerInfo);
f.seekg(0, std::ios::end);
int len = static_cast<int>(f.tellg());
if (len == 0) {
nlohmann::json appRoot;
nlohmann::json app;
app[deviceId] = innerInfo;
appRoot[appName] = app;
f << std::setw(Constants::DUMP_INDENT) << appRoot << std::endl;
} else {
f.seekg(0, std::ios::beg);
nlohmann::json jsonFile;
f >> jsonFile;
if (jsonFile.find(appName) != jsonFile.end()) {
if (jsonFile[appName].find(deviceId) != jsonFile[appName].end()) {
// appName and device id is exist
APP_LOGE("appName = %{public}s is exist", appName.c_str());
ret = false;
} else {
jsonFile[appName][deviceId] = innerInfo;
f.seekp(0, std::ios::beg);
f << std::setw(Constants::DUMP_INDENT) << jsonFile << std::endl;
}
} else {
nlohmann::json app;
app[deviceId] = innerInfo;
jsonFile[appName] = app;
f.seekp(0, std::ios::beg);
f << std::setw(Constants::DUMP_INDENT) << jsonFile << std::endl;
}
}
} else {
APP_LOGI("bundle database file not exist");
ret = false;
}
f.close();
return ret;
}
bool BundleDataStorage::ModifyStorageBundleInfo(
const std::string &deviceId, const InnerBundleInfo &innerBundleInfo) const
{
return true;
}
bool BundleDataStorage::DeleteStorageBundleInfo(
const std::string &deviceId, const InnerBundleInfo &innerBundleInfo) const
{
APP_LOGI("delete bundle data");
bool ret = false;
bool isEmpty = false;
std::string appName = innerBundleInfo.GetApplicationName();
std::ifstream i(Constants::BUNDLE_DATA_BASE_FILE);
nlohmann::json jParse;
if (!i.is_open()) {
APP_LOGE("failed to open bundle database file");
return false;
} else {
i.seekg(0, std::ios::end);
int len = static_cast<int>(i.tellg());
if (len != 0) {
i.seekg(0, std::ios::beg);
i >> jParse;
if (jParse.find(appName) != jParse.end()) {
auto it = jParse[appName].find(deviceId);
if (it != jParse[appName].end()) {
jParse[appName].erase(it);
if (jParse[appName].size() == 0) {
jParse.erase(appName);
if (jParse.size() == 0) {
isEmpty = true;
}
}
ret = true;
}
} else {
APP_LOGE("not find appName = %{public}s", appName.c_str());
}
} else {
APP_LOGE("file is empty appName = %{private}s", appName.c_str());
}
}
i.close();
std::ofstream o(Constants::BUNDLE_DATA_BASE_FILE);
if (!o.is_open()) {
APP_LOGE("failed to open bundle database file");
ret = false;
} else {
if (!isEmpty) {
o << std::setw(Constants::DUMP_INDENT) << jParse;
}
}
o.close();
return ret;
}
bool BundleDataStorage::DeleteStorageModuleInfo(
const std::string &deviceId, const InnerBundleInfo &innerBundleInfo, const std::string &moduleName) const
{
return true;
}
标签：std,get,jsonObject,APP,hpp,appName,c++,Json,BASE 来源： https://blog.csdn.net/llffss/article/details/119107152