利用rapidjson解析嵌套的json

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

废话少说， 直接撸代码：

#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 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;}

结果：

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

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

直接上马：

#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 = "{\"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;}

结果：

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

第二种方式的json串，看起来太恶心了。

另外，再次强调一下，json串解析的时候，容易core dump,所以要做好异常判断，也要注意类型。

总结

以上就是这篇文章的全部内容了，希望本文的内容对大家的学习或者工作具有一定的参考学习价值，谢谢大家对的支持。如果你想了解更多相关内容请查看下面相关链接