Poco迭代嵌套JSON对象

包装商。json实际上重命名为找到的json文件 here .这是代码。确保链接到foundation和json库。

#include <Poco/JSON/Parser.h>
#include <Poco/Dynamic/Var.h>
#include <string>
#include <fstream>
#include <streambuf>
#include <iostream>

void print_version_names(Poco::JSON::Object::Ptr root);

int main(int argc, char** argv)
{
    //read file
    std::ifstream t("packagist.json");
    std::string json_str((std::istreambuf_iterator<char>(t)),
                 std::istreambuf_iterator<char>());

    Poco::JSON::Parser parser;
    Poco::Dynamic::Var result = parser.parse(json_str);
    Poco::JSON::Object::Ptr json = result.extract<Poco::JSON::Object::Ptr>();

    print_version_names(json);

    return 0;
}

void print_version_names(Poco::JSON::Object::Ptr root)
{
    std::string root_key = "package";
    std::string key = "versions";
    //no checks whether such key acually exists
    Poco::JSON::Object::Ptr package_json = root->getObject(root_key);
    //get the nested objects
    Poco::JSON::Object::Ptr nested_versions = package_json->getObject(key);

    //iterate the map
    Poco::JSON::Object::Iterator it;
    for(it = nested_versions->begin(); it != nested_versions->end(); it++)
    {
        //no check of whether it is an object
        std::cout<<it->first<<"\n";
    }
}

结果:

2.0.0
2.0.0-alpha
2.0.0-beta
2.0.0-rc
2.0.1
2.0.10
2.0.11
2.0.11.1
2.0.11.2
2.0.12
2.0.2
2.0.3
2.0.4
2.0.5
2.0.6
2.0.7
2.0.8
2.0.9