利用rapidjson實現解析嵌套的json的方法示例

2020-01-26 13:29:08

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利用rapidjson解析嵌套的json

看json串1：{"system":{"version":"v2.6.1", "name":"value"}}

廢話少說，直接擼代碼：

#include <iostream>#include <stdio.h>#include<unistd.h>#include <sys/types.h>#include <sys/stat.h>#include <fcntl.h>#include<sstream>// 請自己下載開源的rapidjson#include "rapidjson/prettywriter.h"#include "rapidjson/rapidjson.h"#include "rapidjson/document.h"#include "rapidjson/stringbuffer.h"#include "rapidjson/writer.h"#include "rapidjson/memorystream.h"using namespace std;using rapidjson::Document;using rapidjson::StringBuffer;using rapidjson::Writer;using namespace rapidjson;string getVersion(const string &jvStr){ Document document; if (document.Parse(jvStr.c_str()).HasParseError() || !document.HasMember("system"))  { return ""; } const rapidjson::Value &jvObject = document["system"]; if(!jvObject.IsObject()) { return ""; } if(!jvObject.HasMember("version")) { return ""; } const rapidjson::Value &jv = jvObject["version"]; return jv.GetString();}int main(int argc, char *argv[]){ string s = "{/"system/":{/"version/":/"v2.6.1/", /"name/":/"value/"}}"; cout << s << endl; cout << getVersion(s) << endl; return 0;}

結果：

{"system":{"version":"v2.6.1", "name":"value"}}
v2.6.1

再看字符串：{"system": "{/"version/":/"v2.6.1/", /"name/":/"value/"}"}

直接上馬：

#include <iostream>#include <stdio.h>#include<unistd.h>#include <sys/types.h>#include <sys/stat.h>#include <fcntl.h>#include<sstream>// 請自己下載開源的rapidjson#include "rapidjson/prettywriter.h"#include "rapidjson/rapidjson.h"#include "rapidjson/document.h"#include "rapidjson/stringbuffer.h"#include "rapidjson/writer.h"#include "rapidjson/memorystream.h"using namespace std;using rapidjson::Document;using rapidjson::StringBuffer;using rapidjson::Writer;using namespace rapidjson;string getStringFromJson(const string &jsStr, const string &strKey) {   Document document;   if (document.Parse(jsStr.c_str()).HasParseError() || !document.HasMember(strKey.c_str()))    {     return "";   }   const rapidjson::Value &jv = document[strKey.c_str()];   return jv.GetString(); } int main(int argc, char *argv[]){ string s = "{/"system/": /"{///"version///":///"v2.6.1///", ///"name///":///"value///"}/"}"; cout << s << endl; string str = getStringFromJson(s, "system"); cout << str << endl; cout << getStringFromJson(str, "version") << endl; return 0;}

結果：