boost json生成和解析用法

json c++库还是有很多的，因为工作上经常使用boost，这里选用boost的json，记录下用法。

举个栗子：

如果我们要生成如下格式的json:

{
  "name":"jim",
  "info":
  {
    "weight":"",
    "all_phone":
    [
      {
      "phone":""
      },
      {
      "phone":""
      }
    ]
  }
}

解析和生成的示例代码如下

 #include <boost/property_tree/ptree.hpp>
 #include <boost/property_tree/json_parser.hpp>
 #include <boost/foreach.hpp>
 #include <vector>
 using namespace boost::property_tree;
 using namespace std;
 bool CreateJson(wstring &wstr)
 {
     wstringstream wstream;
     try
     {
         wptree pt;
         pt.put(L"name",L"jim");
         wptree info;
         info.put(L"weight",L"");
         wptree phone,phone_item1,phone_item2;
         phone_item1.put(L"phone",L"");
         phone_item2.put(L"phone",L"");
         phone.push_back(make_pair(L"",phone_item1));
         phone.push_back(make_pair(L"",phone_item2));
         info.put_child(L"all_phone",phone);
         pt.push_back(make_pair(L"info",info));
         write_json(wstream,pt);

     }
     catch(ptree_error pt)
     {
       pt.what();
       return false;
     }
     wstr = wstream.str();
     return true;
 }
 bool ParseJson(wstring &wstr)
 {
     try
     {
         wptree pt;
         wstringstream wstream(wstr);
         read_json(wstream,pt);
         wstring wstrName = pt.get<wstring>(L"name");
         wptree info = pt.get_child(L"info");
         wstring weight = info.get<wstring>(L"weight");
         int w=;
         w=info.get<int>(L"weight");
         wptree phones = info.get_child(L"all_phone");
         vector<wstring>vcPhone;
         BOOST_FOREACH(wptree::value_type &v,phones)
         {
             vcPhone.push_back(v.second.get<wstring>(L"phone"));
         }
     }
     catch(ptree_error pt)
     {
         pt.what();
         return false;
     }
     return true;
 }
 int _tmain(int argc, _TCHAR* argv[])
 {
     wstring wstr;
     CreateJson(wstr);
     ParseJson(wstr);
     return ;
 }

用法还是很简单的

这里需要注意的是：

1 boost json不支持空数组,在本例中空数组对应的格式为"all_phone":"";

2  空的字符串字段转换为数字会抛异常。