c++ - 将 json 对象转换为字符串 boost

Question

我是 stackoverflow 的新手，抱歉，如果我有任何错误，请纠正我，如果我错了。我在 boost 中做了很多关于 json 解析器和 xml 解析器的研究。我想做的是，假设我有一个如下所示的 json

      {
           "topology_1":{
           "clnt_id":"aldgdsgsd",
           "sensors":{
                       "num_sensors":"6",
                        "sensor_1":{
                                     "time_interval":"5#15",
                                     "min_bound":"",
                                     "max_bound":"54",
                                     "anomaly":"2%",
                                     "anomaly_window":"70",
                                     "jump":"10",
                                     "topic":"sense/thubrahali/temp",
                                      "qos":"1"
                                   }
                     }
         }
     }

我想将从 boost jsonparser 获取的“topology”的值转换为字符串，以便将它存储在容器中的某个地方供以后使用。现在我不能真正直接通过 theboost 库获取值，因为它将它视为一个 json 对象。我应该如何将此值转换为字符串。

Answer 1

通常需要注意的是，boost 没有 JSON 库。如果您留在 Boost Property Tree 提供的子集中，您可以:

std::string as_json_string(ptree const& pt) {
    std::ostringstream oss;
    write_json(oss, pt);
    return oss.str();
}

演示

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#include <boost/property_tree/json_parser.hpp>
#include <iostream>
using boost::property_tree::ptree;

std::string as_json_string(ptree const& pt) {
    std::ostringstream oss;
    write_json(oss, pt);
    return oss.str();
}

int main() {
    std::istringstream iss(R"({
        "topology_1": {
            "clnt_id": "aldgdsgsd",
            "sensors": {
                "num_sensors": "6",
                "sensor_1": {
                    "time_interval": "5#15",
                    "min_bound": "",
                    "max_bound": "54",
                    "anomaly": "2%",
                    "anomaly_window": "70",
                    "jump": "10",
                    "topic": "sense/thubrahali/temp",
                    "qos": "1"
                }
            }
        }
    })");

    ptree document;
    read_json(iss, document);

    // and back to string
    std::string topology_1 = as_json_string(document.get_child("topology_1"));

    std::cout << topology_1;
}

打印

{
    "clnt_id": "aldgdsgsd",
    "sensors": {
        "num_sensors": "6",
        "sensor_1": {
            "time_interval": "5#15",
            "min_bound": "",
            "max_bound": "54",
            "anomaly": "2%",
            "anomaly_window": "70",
            "jump": "10",
            "topic": "sense\/thubrahali\/temp",
            "qos": "1"
        }
    }
}