c++实现Xml和json互转【转】
https://blog.csdn.net/kfy2011/article/details/51774242
1、下载c语言的cJson库源码,库很小,只有两个文件cJSON.c和cJSON.h。下载地址:https://sourceforge.net/projects/cjson/
2、c++实现Xml和json互转
2.1、头文件
- #include "XmlJsonTransfer.h"
- //#include "cmsDebug.h"
- #include "WebSocket/src/cJSON.h"
- #include <stdlib.h>
- #include <string.h>
- #include <stdio.h>
- #include <assert.h>
- #include <time.h>
- #include <iostream>
- using namespace std;
2.2、xml转json
- // 依赖cJSon,递归
- /*
- <doc><a a1="1" a2="2">123</a></doc> 转 {"doc": {"a": {"-a1": "1","-a2": "2","#text": "123"}}}
- */
- string Xml2Json(string strXml)
- {
- string pNext = strXml;
- cJSON * reJson = cJSON_CreateObject();
- cJSON * jsonArray = cJSON_CreateArray();
- string strArrayKey = "";
- int nPos = 0;
- while ((nPos = pNext.find("<")) >= 0)
- {
- // 获取第一个节点,如:<doc><a a1="1" a2="2">123</a></doc>
- int nPosS = pNext.find("<");
- int nPosE = pNext.find(">");
- if (nPosS < 0 || nPosE < 0)
- {
- printf("key error!");
- }
- string strKey = pNext.substr(nPosS+1, nPosE-nPosS-1);
- // 解释属性,如:<a a1="1" a2="2">
- cJSON * jsonVal = NULL;
- if ((nPos = strKey.find("=")) > 0)
- {
- jsonVal = cJSON_CreateObject();
- int nPos = strKey.find(" ");
- string temp = strKey.substr(nPos+1);
- strKey = strKey.substr(0, nPos);
- while((nPos = temp.find("=")) > 0)
- {
- int nPos1 = temp.find("=");
- int nPos2 = temp.find("\" ", nPos1 + 1);
- string strSubKey = temp.substr(0, nPos1);
- string strSubVal = temp.substr(nPos1+1);
- if (nPos2 > 0)
- strSubVal = temp.substr(nPos1+1, nPos2-nPos1-1);
- // 去除转义字符 \"
- if ((int)(nPos = strSubVal.find("\"")) >= 0)
- {
- int nEnd = strSubVal.find("\\", nPos+1);
- strSubVal = strSubVal.substr(nPos+1, nEnd-nPos-1);
- }
- cJSON_AddItemToObject(jsonVal, ("-" + strSubKey).c_str(), cJSON_CreateString(strSubVal.c_str()));
- if (nPos2 < 0)
- break;
- temp = temp.substr(nPos2+2);
- }
- }
- int nPosKeyE = pNext.find("</" + strKey + ">");
- if (nPosKeyE < 0)
- {
- printf("key error!");
- }
- // 获取节点内容,如<a a1="1" a2="2">123</a> 或 123
- string strVal = pNext.substr(nPosE+1, nPosKeyE-nPosE-1);
- if ((nPos = strVal.find("<")) >= 0)
- {
- // 包含子节点,如<a a1="1" a2="2">123</a>
- strVal = Xml2Json(strVal);
- if (jsonVal)
- {
- if (strVal != "")
- cJSON_AddItemToObject(jsonVal, "#text", cJSON_Parse(strVal.c_str()));
- }
- else
- {
- jsonVal = cJSON_Parse(strVal.c_str());
- }
- }
- else
- {
- // 不包含子节点,如123
- if (jsonVal)
- {
- if (strVal != "")
- cJSON_AddItemToObject(jsonVal, "#text", cJSON_CreateString(strVal.c_str()));
- }
- else
- {
- jsonVal = cJSON_CreateString(strVal.c_str());
- }
- }
- // 获取下一个节点
- pNext = pNext.substr(nPosKeyE + strKey.size() + 3);
- // 根据下一节点判断是否为数组
- int nPosNext = pNext.find("<");
- int nPosNextSame = pNext.find("<" + strKey + ">");
- if (strArrayKey != "" || (nPosNext>=0 && nPosNextSame>=0 && nPosNext==nPosNextSame))
- {
- // 数组
- cJSON_AddItemToArray(jsonArray, jsonVal);
- strArrayKey = strKey;
- }
- else
- {
- // 非数组
- cJSON_AddItemToObject(reJson, strKey.c_str(), jsonVal);
- }
- }
- if (strArrayKey != "")
- {
- cJSON_AddItemToObject(reJson, strArrayKey.c_str(), jsonArray);
- }
- string strJson = cJSON_Print(reJson);
- if(reJson)
- {
- cJSON_Delete(reJson);
- reJson = NULL;
- }
- return strJson;
- }
2.3、json转xml
- // 依赖cJSon,递归
- /*
- {"doc": {"a": {"-a1": "1","-a2": "2","#text": "123"}}} 转 <doc><a a1="1" a2="2">123</a></doc>
- */
- string Json2Xml(string strJson)
- {
- string strXml = "";
- cJSON *root = cJSON_Parse(strJson.c_str());
- if (!root)
- {
- printf("strJson error!");
- return "";
- }
- cJSON *pNext = root->child;
- if (!pNext)
- {
- return strJson;
- }
- int nPos = 0;
- while (pNext)
- {
- string strChild = cJSON_Print(pNext);
- string strVal = Json2Xml(strChild);
- if (pNext->string != NULL)
- {
- string strKey = pNext->string;
- if ((nPos=strKey.find("-")) == 0)
- {
- // 属性项
- strXml.append(" ");
- strXml.append(strKey.substr(1));
- strXml.append("=");
- strXml.append(strVal);
- if (pNext->next == NULL)
- strXml.append(">");
- }
- else if ((nPos=strKey.find("#")) == 0)
- {
- // 值
- strXml.append(">");
- strXml.append(strVal);
- }
- else if ((int)(strVal.find("=")) > 0 /*&& (int)(strVal.find("<")) < 0*/)
- {
- // 包含属性项的键值对
- strXml.append("<" + strKey);
- strXml.append(strVal);
- strXml.append("</" + strKey + ">");
- }
- else
- {
- // 修正底层无键的值数组的键,如:把<JUAN_XJ_preKey>123</JUAN_XJ_preKey>中的JUAN_XJ_preKey修正
- if ((int)strVal.find("JUAN_XJ_preKey") >= 0)
- {
- replace_all(strVal, "JUAN_XJ_preKey", strKey);
- strXml.append(strVal);
- }
- else
- {
- strXml.append("<" + strKey + ">");
- strXml.append(strVal);
- strXml.append("</" + strKey + ">");
- }
- }
- }
- else
- {
- // 不包含键的值数组, 如:["123", "456"],暂时转为<JUAN_XJ_preKey>123</JUAN_XJ_preKey>
- string strPreKey = "JUAN_XJ_preKey";
- strXml.append("<" + strPreKey + ">");
- strXml.append(strVal);
- strXml.append("</" + strPreKey + ">");
- }
- pNext = pNext->next;
- }
- return strXml;
- }
2.4、辅助函数
- // 替换字符串
- string& replace_all(string& str, const string& old_value, const string& new_value)
- {
- while(true)
- {
- string::size_type pos(0);
- if((pos=str.find(old_value)) != string::npos)
- str.replace(pos,old_value.length(),new_value);
- else
- break;
- }
- return str;
- }
饮水思源,不忘初心。
要面包,也要有诗和远方。