C++中rapidjson将嵌套map转为嵌套json的讲解

2020-01-26 13:29:12

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rapidjson将嵌套map转为嵌套json------人生苦短，我用rapidjson

看代码：

#include <iostream>#include <map>// 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 formJson(const map<string, int> &mInt, const map<string, string> &mString,     const string &strChild, const map<string, int> &mChildInt, const map<string, string> &mChildString){ Document document;  Document::AllocatorType& allocator = document.GetAllocator();   Value root(kObjectType);  Value child(kObjectType);  Value key(kStringType);   Value value(kStringType);  // 当前级别 for(map<string, int>::const_iterator it = mInt.begin(); it != mInt.end(); ++it)  { key.SetString(it->first.c_str(), allocator);    root.AddMember(key, it->second, allocator); } for(map<string, string>::const_iterator it = mString.begin(); it != mString.end(); ++it) { key.SetString(it->first.c_str(), allocator);    value.SetString(it->second.c_str(), allocator);    root.AddMember(key, value, allocator); } // 孩子级别 if(!strChild.empty()) { for(map<string, int>::const_iterator it = mChildInt.begin(); it != mChildInt.end(); ++it)  {  key.SetString(it->first.c_str(), allocator);    child.AddMember(key, it->second, allocator); } for(map<string, string>::const_iterator it = mChildString.begin(); it != mChildString.end(); ++it) {  key.SetString(it->first.c_str(), allocator);    value.SetString(it->second.c_str(), allocator);    child.AddMember(key, value, allocator); } key.SetString(strChild.c_str(), allocator);  root.AddMember(key, child, allocator); }  StringBuffer buffer;   Writer<StringBuffer> writer(buffer);   root.Accept(writer);   return buffer.GetString(); }int main(int argc, char *argv[]){ map<string, int> mInt; mInt["code"] = 0; mInt["score"] = 80; map<string, string> mString; mString["name"] = "taoge"; mString["place"] = "shenzhen"; string strChild = "childNode"; map<string, int> mChildInt; mChildInt["code"] = 0; mChildInt["score"] = 100; map<string, string> mChildString; mChildString["name"] = "taogeChild"; mChildString["place"] = "shenzhen"; string strJson = formJson(mInt, mString,             strChild, mChildInt, mChildString); cout << strJson << endl; return 0;}

结果：

{"code":0,"score":80,"name":"taoge","place":"shenzhen","childNode":{"code":0,"score":100,"name":"taogeChild","place":"shenzhen"}}

另外，如果仅仅想有当前界别，那么，可以这么搞（C++默认参数搞起）：

#include <iostream>#include <map>// 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;map<string, int> g_mChildInt;map<string, string> g_mChildString;string formJson(const map<string, int> &mInt, const map<string, string> &mString,     const string &strChild="", const map<string, int> &mChildInt=g_mChildInt, const map<string, string> &mChildString=g_mChildString){ Document document;  Document::AllocatorType& allocator = document.GetAllocator();   Value root(kObjectType);  Value child(kObjectType);  Value key(kStringType);   Value value(kStringType);  // 当前级别 for(map<string, int>::const_iterator it = mInt.begin(); it != mInt.end(); ++it)  { key.SetString(it->first.c_str(), allocator);    root.AddMember(key, it->second, allocator); } for(map<string, string>::const_iterator it = mString.begin(); it != mString.end(); ++it) { key.SetString(it->first.c_str(), allocator);    value.SetString(it->second.c_str(), allocator);    root.AddMember(key, value, allocator); } // 孩子级别 if(!strChild.empty()) { for(map<string, int>::const_iterator it = mChildInt.begin(); it != mChildInt.end(); ++it)  {  key.SetString(it->first.c_str(), allocator);    child.AddMember(key, it->second, allocator); } for(map<string, string>::const_iterator it = mChildString.begin(); it != mChildString.end(); ++it) {  key.SetString(it->first.c_str(), allocator);    value.SetString(it->second.c_str(), allocator);    child.AddMember(key, value, allocator); } key.SetString(strChild.c_str(), allocator);  root.AddMember(key, child, allocator); }  StringBuffer buffer;   Writer<StringBuffer> writer(buffer);   root.Accept(writer);   return buffer.GetString(); }int main(int argc, char *argv[]){ map<string, int> mInt; mInt["code"] = 0; mInt["score"] = 80; map<string, string> mString; mString["name"] = "taoge"; mString["place"] = "shenzhen"; string strJson = formJson(mInt, mString); cout << strJson << endl; return 0;}

结果：