How to realize data Reading by JsonCpp
This article mainly introduces JsonCpp how to achieve data reading, the article is very detailed, has a certain reference value, interested friends must read it!
Jsoncpp is a cross-platform open source library for C++. Download address: http://sourceforge.net/projects/jsoncpp/. Assert as an error handling method, will stop the running of the program, remember!
1) parsing json information from a file
Std::ifstream ifs
Ifs.open ("testdata.json", std::ios::binary)
Json::Reader reader (Json::Features::strictMode ())
Json::Value root
If (NULL = = reader.parse (ifs, root))
{
Ifs.close ()
Return
}
Ifs.close ()
2) parsing json information from cache
Std::string strJsonText = "{\" total\ ": 1,\" toReturn\ ": [{\" createTime\ ":\" 200808061145260000800\ ",\" createUser\ ":\" Zhang San\ "}],\" success\ ": false}"
Json::Reader reader (Json::Features::strictMode ())
Json::Value root
If (NULL = = reader.parse (istrJsonText, root)) return
Note:
1)
When JsonCpp parses illegal json, it will actively tolerate fault into character types, and when the character type is subscript, the assert termination program will be triggered. Solution: enable strict mode, return false when parsing illegal json, and no longer automatically tolerate faults. When creating a read object, specify the property: Json::Reader reader (Json::Features::strictMode ())
Use of Json::Reader reader is not recommended
2) if the text file in Json format is opened with Windows notepad, the BOM logo may be added to the text, resulting in reading failure. It is recommended to use Notepad++ to modify and view it.
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