前言
这个是我闲着没事写的，这个解析器还有两个问题
1.读取中文的时候会出错，这个应该是在读取文件的时候用的char没用wchar_t
2.当Json文本有列表和对象多层嵌套的时候会出问题，目前这个解析两层的没有问题，再多就会出错，以后再改了
写的不好，慢慢练了
代码
JsonSerialize.h
#pragma once
#ifndef _JSON_SERIALIZE_
#define _JSON_SERIALIZE_
// #include "Util.h"
#include <fstream>
#include <string>
#include <vector>
#include <map>
// NAME_SPACE_START(Json)
enum JsonType {
None,
Number,
String,
Array,
Bool,
Null,
Object
};
class JNull {
public:
JNull() {}
~JNull() {}
};
template<typename T>
class JBaseObject {
public:
JBaseObject() {}
virtual ~JBaseObject() {}
virtual JBaseObject* clone() = 0;
};
template<typename T>
class JHolderObject :public JBaseObject<T> {
private:
public:
T value;
JHolderObject(const T& val) :value(val) {}
~JHolderObject() {}
JBaseObject<T>* clone() override;
};
template<typename ValueType>
class JObject {
private:
JBaseObject<ValueType>* _value = nullptr;
public:
JObject() {}
JObject(const ValueType& value);
JObject(const JObject& obj) :_value(obj._value->clone()) {}
~JObject();
JObject<ValueType>& operator=(const ValueType& value);
ValueType* Cast() {
JHolderObject<ValueType>* temp = dynamic_cast<JHolderObject<ValueType>*>(_value);
return temp ? &temp->value : NULL;
}
ValueType& RefCast() {
return (static_cast<JHolderObject<ValueType>*>(_value))->value;
}
};
template<typename T>
class JsonItemBase {
public:
JsonItemBase() {}
virtual ~JsonItemBase() {}
virtual void f() {}
};
template<typename T>
class JsonItem {
private:
// JObject<T> _value;
T _value;
public:
JsonItem() {}
JsonItem(const JsonItem&);
JsonItem(const JObject<T>& obj);
JsonItem(const T& obj);
~JsonItem() {};
T& GetItemRefValue() {
return this->_value;
}
T* GetItemLpValue() {
return &this->_value;
}
};
class JsonKey {
public:
JsonType _type{ JsonType::None };
std::wstring _key{ L"" };
JsonKey() {}
JsonKey(const JsonType& type, const std::wstring& key) :_type(type), _key(key) {}
bool operator<(const JsonKey&) const;
};
class JsonValue {
public:
void* _value{ nullptr };
size_t _size{ 0 };
JsonValue() {}
JsonValue(void* value, const int& size) :_value(value), _size(size) {}
};
class JsonSerialize {
using string = std::string;
private:
std::vector<std::pair<JsonKey, JsonValue>> content;
string _filePath;
public:
JsonSerialize() {}
JsonSerialize(const string filePath);
~JsonSerialize() {};
bool Load(const string filePath = "");
template<typename T>
JsonItem<T>* GetValueByKey(string key);
std::vector<std::pair<JsonKey, JsonValue>>& GetContent();
void printAll(int tab = 0);
private:
};
// NAME_SPACE_END()
#endif //!_JSON_SERIALIZE_
JsonSerialize.cpp
#include "JsonSerialize.h"
// #include "Util.h"
#include <iostream>
#include <sstream>
#include <atomic>
#include <exception>
#include <fstream>
#include <ios>
#include <string>
#include <utility>
#include <vector>
#include <stack>
// NAME_SPACE_START(Json)
template<typename T>
JBaseObject<T>* JHolderObject<T>::clone() {
return new JHolderObject<T>(this->value);
}
// template<typename T>
// T& JHolderObject<T>::GetValue(){
// return value;
// }
template<typename ValueType>
JObject<ValueType>::JObject(const ValueType& value) {
_value = new JHolderObject<ValueType>(value);
}
template<typename ValueType>
JObject<ValueType>::~JObject() {
if (_value) delete _value;
}
template<typename ValueType>
JObject<ValueType>& JObject<ValueType>::operator=(const ValueType& value) {
if (_value) delete _value;
_value = new JHolderObject<ValueType>(value);
return *this;
}
// template<typename ValueType>
// ValueType* JObject<ValueType>::Cast(){
// JHolderObject<ValueType>* temp=dynamic_cast<JHolderObject<ValueType>*>(_value);
// return temp?&temp->GetValue():NULL;
// }
// template<typename ValueType>
// ValueType& JObject<ValueType>::RefCast(){
// return (dynamic_cast<JHolderObject<ValueType>&>(_value)).GetValue();
// }
// template<typename T>
// JsonItem<T>::JsonItem(const JObject<T>& value)
// :JsonItemBase<T>(){
// this->_value=value;
// }
template<typename T>
JsonItem<T>::JsonItem(const T& objList)
{
this->_value = objList;
}
// //获取值
// template<typename T>
// T& JsonItem<T>::GetItemRefValue(){
// return this->_value.RefCast();
// }
// template<typename T>
// T* JsonItem<T>::GetItemLpValue(){
// return this->_value.Cast();
// }
std::ifstream _file;
void OpenFile(const std::string filePath) {
_file.open(filePath, std::ios::in);
if (!_file.is_open()) return;
}
void CloseFile() {
_file.close();
}
bool JsonKey::operator<(const JsonKey& j_key) const {
return false;
}
JsonSerialize::JsonSerialize(const std::string filePath) {
this->_filePath = filePath;
}
bool isFirst = true;
bool isQuote = false;
bool isKey = true;
bool isObj = false;
bool isObjEnd = true;
bool isArrEnd = true;
JsonType curType = JsonType::Null;
size_t objListDeep = 0;
size_t arrDeep = 0;
std::wstring key = L"";
std::wstring value = L"";
std::stack<std::wstring> arrKey;
std::stack<JsonType> cer;
std::vector<std::pair<bool,JsonItem<std::vector<JsonValue>>*>> arrValueList; //false直接放到对象中 true 放到objList中
std::vector<std::pair<bool,JsonItem<JsonSerialize>*>> objList; //false直接放到对象中 true 放到arrValueList中
void freeAll() {
for (std::pair<bool, JsonItem<std::vector<JsonValue>>*> item : arrValueList)
if (item.second) delete item.second;
for (std::pair<bool, JsonItem<JsonSerialize>*> item : objList)
if (item.second) delete item.second;
}
std::string stows(std::wstring& ws)
{
std::string curLocale = setlocale(LC_ALL, NULL); // curLocale = "C";
setlocale(LC_ALL, "chs");
const wchar_t* _Source = ws.c_str();
size_t _Dsize = 2 * ws.size() + 1;
char* _Dest = new char[_Dsize];
memset(_Dest, 0, _Dsize);
wcstombs(_Dest, _Source, _Dsize);
std::string result = _Dest;
delete[]_Dest;
setlocale(LC_ALL, curLocale.c_str());
return result;
}
bool isBool(const std::wstring& str) {
return str == L"true";
}
bool isNumber(const std::wstring& str) {
std::wstring wstr = str;
std::stringstream ss(stows(wstr));
double d;
char c;
if (!(ss >> d)) return false;
if (ss >> c) return false;
return true;
}
bool Analysis(const char* buffer, std::vector<std::pair<JsonKey, JsonValue>>& content, const size_t length) {
size_t charLength = strlen(buffer) < length ? strlen(buffer) : length;
for (size_t i = 0; i < charLength; i++) {
char ch = buffer[i];
std::cout << ch;
if (ch == '{' && !isQuote) {
objListDeep++;
curType = JsonType::Object;
if (objListDeep >= 2) {
bool flag = (cer.empty() || cer.top() == JsonType::Object) ? false : true;
objList.push_back(std::pair<bool, JsonItem<JsonSerialize>*>(flag, new JsonItem<JsonSerialize>()));
isObj = true;
isObjEnd = false;
if (!isArrEnd) cer.push(JsonType::Array);
cer.push(JsonType::Object);
if (isKey) arrKey.push(L"");
}
}
else if (ch == '}' && !isQuote) {
if (objListDeep == 1 && isFirst == true) isFirst = false;
else if (objListDeep == 1 && isFirst == false) return false;
objListDeep--;
isObjEnd = true;
if (objListDeep != 0)
goto addArray;
}
else if (ch == '[' && !isQuote) {
bool flag = (cer.empty() || cer.top() == JsonType::Object) ? false : true;
curType = JsonType::Array;
arrDeep++;
arrValueList.push_back(std::pair<bool, JsonItem<std::vector<JsonValue>>*>(flag,new JsonItem<std::vector<JsonValue>>()));
isArrEnd = false;
if (!isObjEnd) cer.push(JsonType::Object);
cer.push(JsonType::Array);
}
else if (ch == ']' && !isQuote) {
arrDeep--;
if (arrDeep == 0) isArrEnd = true;
goto addArray;
}
else if (ch == ' ' && !isQuote) continue;
else if (ch == '"' && !isQuote) {
isQuote = true;
if (isKey) key += L"\"";
else value += L"\"";
}
else if (ch == '"' && isQuote) {
isQuote = false;
if (isKey) key += L"\"";
else value += L"\"";
}
else if (ch == ':' && !isQuote) isKey = false;
else if ((ch == ',' || ch == '\n') && !isQuote) {
if ((key == L"" && value == L"" && objList.size() == 0 && arrValueList.size() == 0)
|| (key == L"" && value == L"" && !isArrEnd)) continue;
addArray: std::wstring inputKey = key == L"" ? L"" : key.replace(0, 1, L"");
inputKey = inputKey == L"" ? L"" : inputKey.replace(inputKey.find_last_of(L"\""), 1, L"");
JsonKey j_key;
JsonValue j_value;
JsonType insertType = JsonType::Null;
j_key._key = inputKey;
if (value == L"true" || value == L"false") { //Bool
JsonItem<bool> *objList=new JsonItem<bool>(isBool(value));
size_t size = sizeof(objList);
j_value._value = objList;
j_value._size = 1;
j_key._type = JsonType::Bool;
}
else if (value.find(L"\"") == 0 && value.find_last_of(L"\"") == value.size() - 1) { //String
size_t n = value.size();
std::wstring* temp = new std::wstring(value.begin(), value.end());
JsonItem<std::wstring*> *objList=new JsonItem<std::wstring*>(temp);
j_value._value = objList;
j_value._size = n;
j_key._type = JsonType::String;
}
else if (isNumber(value)) { //Number
double result = 0;
std::stringstream ss(stows(value));
ss >> result;
JsonItem<double> *objList=new JsonItem<double>(result);
size_t size = sizeof(objList);
j_value._value = objList;
//memcpy_s(j_value._value, size, &objList, size);
j_value._size = 1;
j_key._type = JsonType::Number;
}
else if (arrValueList.size() != 0 && objList.size() != 0) {//Array Add or Object Add
if (!isObjEnd) {
arrKey.push(inputKey);
key = L"";
isKey = true;
continue;
}
cer.pop();
void* _val = curType == JsonType::Object ? (void*)objList.back().second : (void*)arrValueList.back().second;
size_t _si = curType == JsonType::Object ?
objList.back().second->GetItemRefValue().GetContent().size() :
arrValueList.back().second->GetItemLpValue()->size();
j_key._key = arrKey.top();
j_value._value = _val;
j_value._size = _si;
j_key._type = JsonType::Object;
if (curType == JsonType::Object) objList.pop_back();
else arrValueList.pop_back();
//接下来确认是放到obj 还是 arrvalue 通过cer栈顶元素判断
JsonType upType = cer.top();
arrKey.pop();
if (upType == JsonType::Object)
objList.back().second->GetItemLpValue()->GetContent().push_back(std::pair<JsonKey, JsonValue>(j_key, j_value));
else
arrValueList.back().second->GetItemLpValue()->push_back(j_value);
continue;
}
else if (objList.size() != 0) {//Object
if (!isObjEnd && isKey) {
arrKey.push(inputKey);
key = L"";
continue;
}
cer.pop();
j_key._key = arrKey.top();
arrKey.pop();
j_value._value = objList.back().second;
j_value._size = objList.back().second->GetItemRefValue().GetContent().size();
j_key._type = JsonType::Object;
objList.pop_back();
if (objList.size() != 0) {
objList.back().second->GetItemLpValue()->GetContent().push_back(std::pair<JsonKey, JsonValue>(j_key, j_value));
continue;
}
}
else if (arrValueList.size() != 0 && objList.size() == 0) {//Array
if (!isArrEnd) {
arrKey.push(inputKey);
key = L"";
isKey = true;
continue;
}
cer.pop();
j_key._key = arrKey.empty()?inputKey:arrKey.top();
if (!arrKey.empty()) arrKey.pop();
j_value._value = arrValueList.back().second;
j_value._size = arrValueList.back().second->GetItemLpValue()->size();
j_key._type = JsonType::Array;
arrValueList.pop_back();
if (arrValueList.size() != 0) {
arrValueList.back().second->GetItemLpValue()->push_back(j_value);
continue;
}
}
else if (value == L"") { //Null
JsonItem<JNull>* objList = new JsonItem<JNull>();
size_t size = sizeof(objList);
j_value._value = objList;
j_value._size = 0;
j_key._type = JsonType::Null;
}
std::pair<JsonKey, JsonValue> pair(j_key, j_value);
if (!isObjEnd) {
objList.back().second->GetItemRefValue().GetContent().push_back(pair);
}
else content.push_back(pair);
key = L"";
value = L"";
isKey = true;
if (objListDeep == 1 && isObj) isObj = false;
}
else {
if (isKey && isQuote) key += std::wstring(1, ch);
else if (isKey && !isQuote) return false;
else if (!isKey) value += std::wstring(1, ch);
}
if (objListDeep < 0 || arrDeep < 0) return false;
}
return true;
}
bool JsonSerialize::Load(const string filePath) {
try {
if (filePath != "") {
this->_filePath = filePath;
}
OpenFile(this->_filePath);
while (!_file.eof()) {
char buffer[0x4000] = "";
size_t length = sizeof(buffer) / sizeof(char);
_file.read(buffer, length);
if (!Analysis(buffer, content, length)) {
CloseFile();
return false;
}
}
CloseFile();
freeAll();
return objListDeep == 0 && arrDeep == 0;
}
catch (std::exception ex) {
throw ex;
}
}
std::vector<std::pair<JsonKey, JsonValue>>& JsonSerialize::GetContent() {
return this->content;
}
template<typename T>
JsonItem<T>* JsonSerialize::GetValueByKey(string key)
{
JsonItem<T>* temp_value = nullptr;
for (auto item : this->content) {
if (item.first._key == key) {
temp_value = (JsonItem<T>*)(item.second._value);
break;
}
}
return temp_value;
}
void coutTab(int count) {
while (count--) {
std::cout << '\t';
}
}
void JsonSerialize::printAll(int tab) {
auto res = this->content;
coutTab(tab);
std::cout << "{" << std::endl;
for (auto it = res.begin(); it != res.end(); it++) {
JsonKey temp_key = it->first;
if (temp_key._type == JsonType::Number) {
JsonItem<double>* temp_value = (JsonItem<double>*)(it->second._value);
coutTab(tab + 1);
std::wcout << temp_key._key << " : " << temp_value->GetItemRefValue() << std::endl;
}
else if (temp_key._type == JsonType::String) {
JsonItem<std::wstring*>* temp_value = (JsonItem<std::wstring*>*)(it->second._value);
coutTab(tab + 1);
std::wcout << temp_key._key << " : " << *temp_value->GetItemRefValue() << "" << std::endl;
}
else if (temp_key._type == JsonType::Null) {
JsonItem<JNull>* temp_value = (JsonItem<JNull>*)(it->second._value);
coutTab(tab + 1);
std::wcout << temp_key._key << " : " << "NULL" << std::endl;
}
else if (temp_key._type == JsonType::Bool) {
JsonItem<bool>* temp_value = (JsonItem<bool>*)(it->second._value);
coutTab(tab + 1);
std::wcout << temp_key._key << " : " << (temp_value->GetItemRefValue() ? "true" : "false") << std::endl;
}
else if (temp_key._type == JsonType::Object) {
JsonItem<JsonSerialize>* temp_value = (JsonItem<JsonSerialize>*)(it->second._value);
temp_value->GetItemRefValue().printAll(tab + 1);
}
else if (temp_key._type == JsonType::Array) {
JsonItem<std::vector<JsonValue>>* temp_value =
(JsonItem<std::vector<JsonValue>>*)(it->second._value);
coutTab(tab + 1);
std::wcout << temp_key._key << ":[" << std::endl;
for (auto item : temp_value->GetItemRefValue()) {
JsonItem<JsonSerialize>* tt_value = (JsonItem<JsonSerialize>*)(item._value);
tt_value->GetItemLpValue()->printAll(tab + 2);
}
coutTab(tab + 1);
std::cout << "]" << std::endl;
}
}
coutTab(tab);
std::cout << "}" << std::endl;
}
// NAME_SPACE_END()
main.cpp
int main() {
JsonSerialize json("F:\\C++\\mySource\\example\\test.json");
json.Load();
json.printAll();
return 0;
}
到此这篇关于基于C++编写一个Json解析器的文章就介绍到这了,更多相关C++ Json解析器内容请搜索编程网以前的文章或继续浏览下面的相关文章希望大家以后多多支持编程网！
