直接看代码:
结果:
- #include <iostream>
- #include <stdio.h>
- #include<unistd.h>
- #include <sys/types.h>
- #include <sys/stat.h>
- #include <fcntl.h>
- #include<sstream>
- // 请自己下载开源的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 = "{\"code\":0,\"msg\":\"ok\"}";
- cout << s << endl;
- cout << getStringFromJson(s,"msg") << endl;
- return 0;
- }
{"code":0,"msg":"ok"}
ok
注意:
1. 如果不进行document.Parse(jsStr.c_str()).HasParseError()判断, 则很容易core dump
2. 如果不进行!document.HasMember(strKey.c_str())判断, 则很容易core dump
3. code的是为0, 是整数, 如果调用上述getStringFromJson, 会core dump,此时应该用return jv.GetInt();
OK,不多说, 人生苦短, 我爱rapidjson