json串转成对象
cInfraredData* cInfraredData::to_obj(char* jsonstr) { cInfraredData* p = new cInfraredData(); Document doc; doc.Parse(jsonstr); if (doc.HasMember("ipAddress")) { rapidjson::Value &val_ipAddress = doc["ipAddress"]; if (val_ipAddress.IsString()) { p->ipAddress = val_ipAddress.GetString(); } } if (doc.HasMember("dateTime")) { rapidjson::Value &val_dateTime = doc["dateTime"]; if (val_dateTime.IsString()) { p->dateTime = val_dateTime.GetString(); } } if (doc.HasMember("backgroundPic")) { rapidjson::Value &val_backgroundPic = doc["backgroundPic"]; if (val_backgroundPic.IsString()) { p->backgroundPic = val_backgroundPic.GetString(); } } if (doc.HasMember("backgroundPicThermal")) { rapidjson::Value &val_backgroundPic = doc["backgroundPicThermal"]; if (val_backgroundPic.IsString()) { p->backgroundPicThermal = val_backgroundPic.GetString(); } } if (doc.HasMember("temperatureList") && doc["temperatureList"].IsArray()) { rapidjson::Value &list = doc["temperatureList"]; for (unsigned int i = 0; i < list.Size(); i++) { const rapidjson::Value& object = list[i]; if (object.IsObject()) { sAlarmVlPicAxis s={0,0,0,0,0.0}; if (object.HasMember("alarmVlPicLeftTopX") && object["alarmVlPicLeftTopX"].IsInt()) s.alarmVlPicLeftTopX = object["alarmVlPicLeftTopX"].GetInt(); if (object.HasMember("alarmVlPicLeftTopY") && object["alarmVlPicLeftTopY"].IsInt()) s.alarmVlPicLeftTopY = object["alarmVlPicLeftTopY"].GetInt(); if (object.HasMember("alarmVlPicRightBottomX") && object["alarmVlPicRightBottomX"].IsInt()) s.alarmVlPicRightBottomX = object["alarmVlPicRightBottomX"].GetInt(); if (object.HasMember("alarmVlPicRightBottomY") && object["alarmVlPicRightBottomY"].IsInt()) s.alarmVlPicRightBottomY = object["alarmVlPicRightBottomY"].GetInt(); if (object.HasMember("temperature") && object["temperature"].IsFloat()) s.temperature = object["temperature"].GetFloat(); p->temperatureList.push_back(s); } } } if (doc.HasMember("temperatureNormalList")) { rapidjson::Value &list = doc["temperatureNormalList"]; if (list.IsArray()) { for (unsigned int i = 0; i < list.Size(); i++) { rapidjson::Value & val = list[i]; if(val.IsBool()) p->temperatureNormalList.push_back(val.GetBool()); } } } return p; }
{ "Int": 1, "Double": 12.0000001, "String": "This is a string", "Object": { "name": "qq849635649", "age": 25 }, "IntArray": [ 10, 20, 30 ], "DoubleArray": [ 1, 2, 3 ], "StringArray": [ "one", "two", "three" ], "MixedArray": [ "one", 50, false, 12.005 ], "People": [ { "name": "qq849635649", "age": 0, "sex": true }, { "name": "qq849635649", "age": 10, "sex": false }, { "name": "qq849635649", "age": 20, "sex": true } ] } 一、写json协议 1. 下面这段代码是我最喜欢用的一种方式，使用字符串缓冲器生成 #include "rapidjson/stringbuffer.h" #include "rapidjson/writer.h" #include <iostream> #include <string> using namespace std; void Serialize_1() { rapidjson::StringBuffer strBuf; rapidjson::Writer<rapidjson::StringBuffer> writer(strBuf); writer.StartObject(); //1. 整数类型 writer.Key("Int"); writer.Int(1); //2. 浮点类型 writer.Key("Double"); writer.Double(12.0000001); //3. 字符串类型 writer.Key("String"); writer.String("This is a string"); //4. 结构体类型 writer.Key("Object"); writer.StartObject(); writer.Key("name"); writer.String("qq849635649"); writer.Key("age"); writer.Int(25); writer.EndObject(); //5. 数组类型 //5.1 整型数组 writer.Key("IntArray"); writer.StartArray(); //顺序写入即可 writer.Int(10); writer.Int(20); writer.Int(30); writer.EndArray(); //5.2 浮点型数组 writer.Key("DoubleArray"); writer.StartArray(); for(int i = 1; i < 4; i++) { writer.Double(i * 1.0); } writer.EndArray(); //5.3 字符串数组 writer.Key("StringArray"); writer.StartArray(); writer.String("one"); writer.String("two"); writer.String("three"); writer.EndArray(); //5.4 混合型数组 //这说明了，一个json数组内容是不限制类型的 writer.Key("MixedArray"); writer.StartArray(); writer.String("one"); writer.Int(50); writer.Bool(false); writer.Double(12.005); writer.EndArray(); //5.5 结构体数组 writer.Key("People"); writer.StartArray(); for(int i = 0; i < 3; i++) { writer.StartObject(); writer.Key("name"); writer.String("qq849635649"); writer.Key("age"); writer.Int(i * 10); writer.Key("sex"); writer.Bool((i % 2) == 0); writer.EndObject(); } writer.EndArray(); writer.EndObject(); string data = strBuf.GetString(); cout << data << endl; } 2. 接下来这种方式是我刚开始学习使用该库时网上收到的结果，使用不像上面那么方便 #include "rapidjson/document.h" #include "rapidjson/stringbuffer.h" #include "rapidjson/writer.h" void Serialize_2() { rapidjson::Document doc; doc.SetObject(); rapidjson::Document::AllocatorType& allocator = doc.GetAllocator(); //1. 整型类型 doc.AddMember("Int", 1, allocator); //2. 浮点类型 doc.AddMember("Double", 12.00001, allocator); //3. 字符串类型 //正确方式 string str= "This is a string"; rapidjson::Value str_value(rapidjson::kStringType); str_value.SetString(str.c_str(), str.size()); if(!str_value.IsNull()) { doc.AddMember("String", str_value, allocator); } /** * 注：以下方式不正确，可能成功，也可能失败，因为字符串写入json要重新开辟内存， * 如果使用该方式的话，当数据是字符串常量的话是没问题的，如果为变量就会显示乱码，所 * 以为保险起见，我们显式的分配内存(无需释放) */ //doc.AddMember("String", str.data(), allocator); //4. 结构体类型 rapidjson::Value object(rapidjson::kObjectType); object.AddMember("name", "qq849635649", allocator); //注：常量是没有问题的 object.AddMember("age", 25, allocator); doc.AddMember("Object", object, allocator); //5. 数组类型 //5.1 整型数组 rapidjson::Value IntArray(rapidjson::kArrayType); IntArray.PushBack(10, allocator); IntArray.PushBack(20, allocator); IntArray.PushBack(30, allocator); doc.AddMember("IntArray", IntArray, allocator); //5.2 浮点型数组 rapidjson::Value DoubleArray(rapidjson::kArrayType); DoubleArray.PushBack(1.0, allocator); DoubleArray.PushBack(2.0, allocator); DoubleArray.PushBack(3.0, allocator); doc.AddMember("DoubleArray", DoubleArray, allocator); //5.3 字符型数组 rapidjson::Value StringArray(rapidjson::kArrayType); string strValue1 = "one"; string strValue2 = "two"; string strValue3 = "three"; str_value.SetString(strValue1.c_str(), strValue1.size()); StringArray.PushBack(str_value, allocator); str_value.SetString(strValue2.c_str(), strValue2.size()); StringArray.PushBack(str_value, allocator); str_value.SetString(strValue3.c_str(), strValue3.size()); StringArray.PushBack(str_value, allocator); doc.AddMember("StringArray", StringArray, allocator); //5.4 结构体数组 rapidjson::Value ObjectArray(rapidjson::kArrayType); for(int i = 1; i < 4; i++) { rapidjson::Value obj(rapidjson::kObjectType); obj.AddMember("name", "qq849635649", allocator);//注：常量是没有问题的 obj.AddMember("age", i * 10, allocator); ObjectArray.PushBack(obj, allocator); } doc.AddMember("ObjectArray", ObjectArray, allocator); rapidjson::StringBuffer strBuf; rapidjson::Writer<rapidjson::StringBuffer> writer(strBuf); doc.Accept(writer); string data = strBuf.GetString(); cout << data << endl; } 下面是解析的代码，同样的，采用的依旧上面那个json字符串，分门别类的已经整理好 #include "rapidjson/document.h" #include "rapidjson/stringbuffer.h" #include "rapidjson/writer.h" string data = "{"Int":1," ""Double":12.0000001," ""String":"This is a string"," ""Object":{"name":"qq849635649","age":25}," ""IntArray":[10,20,30]," ""DoubleArray":[1.0,2.0,3.0]," ""StringArray":["one","two","three"]," ""MixedArray":["one",50,false,12.005]," ""People":[{"name":"qq849635649","age":0,"sex":true}," "{"name":"qq849635649","age":10,"sex":false}," "{"name":"qq849635649","age":20,"sex":true}]}"; void parse() { //创建解析对象 rapidjson::Document doc; //首先进行解析，没有解析错误才能进行具体字段的解析 if(!doc.Parse(data.data()).HasParseError()) { //1. 解析整数 if(doc.HasMember("Int") && doc["Int"].IsInt()) { cout << "Int = " << doc["Int"].GetInt() << endl; } //2. 解析浮点型 if(doc.HasMember("Double") && doc["Double"].IsDouble()) { cout << "Double = " << doc["Double"].GetDouble() << endl; } //3. 解析字符串 if(doc.HasMember("String") && doc["String"].IsString()) { cout << "String = " << doc["String"].GetString() << endl; } //4. 解析结构体 if(doc.HasMember("Object") && doc["Object"].IsObject()) { const rapidjson::Value& object = doc["Object"]; if(object.HasMember("name") && object["name"].IsString()) { cout << "Object.name = " << object["name"].GetString() << endl; } if(object.HasMember("age") && object["age"].IsInt()) { cout << "Object.age = " << object["age"].GetInt() << endl; } } //5. 解析数组类型 //5.1 整型数组类型 if(doc.HasMember("IntArray") && doc["IntArray"].IsArray()) { //5.1.1 将字段转换成为rapidjson::Value类型 const rapidjson::Value& array = doc["IntArray"]; //5.1.2 获取数组长度 size_t len = array.Size(); //5.1.3 根据下标遍历，注意将元素转换为相应类型，即需要调用GetInt() for(size_t i = 0; i < len; i++) { cout << "IntArray[" << i << "] = " << array[i].GetInt() << endl; } } //5.2 浮点型数组类型 if(doc.HasMember("DoubleArray") && doc["DoubleArray"].IsArray()) { const rapidjson::Value& array = doc["DoubleArray"]; size_t len = array.Size(); for(size_t i = 0; i < len; i++) { //为防止类型不匹配，一般会添加类型校验 if(array[i].IsDouble()) { cout << "DoubleArray[" << i << "] = " << array[i].GetDouble() << endl; } } } //5.3 字符串数组类型 if(doc.HasMember("StringArray") && doc["StringArray"].IsArray()) { const rapidjson::Value& array = doc["StringArray"]; size_t len = array.Size(); for(size_t i = 0; i < len; i++) { //为防止类型不匹配，一般会添加类型校验 if(array[i].IsString()) { cout << "StringArray[" << i << "] = " << array[i].GetString() << endl; } } } //5.4 混合型 if(doc.HasMember("MixedArray") && doc["MixedArray"].IsArray()) { const rapidjson::Value& array = doc["MixedArray"]; size_t len = array.Size(); for(size_t i = 0; i < len; i++) { //为防止类型不匹配，一般会添加类型校验 if(array[i].IsString()) { cout << "MixedArray[" << i << "] = " << array[i].GetString() << endl; } else if(array[i].IsBool()) { cout << "MixedArray[" << i << "] = " << array[i].GetBool() << endl; } else if(array[i].IsInt()) { cout << "MixedArray[" << i << "] = " << array[i].GetInt() << endl; } else if(array[i].IsDouble()) { cout << "MixedArray[" << i << "] = " << array[i].GetDouble() << endl; } } } //5.5 结构体数组类型 if(doc.HasMember("People") && doc["People"].IsArray()) { const rapidjson::Value& array = doc["People"]; size_t len = array.Size(); for(size_t i = 0; i < len; i++) { const rapidjson::Value& object = array[i]; //为防止类型不匹配，一般会添加类型校验 if(object.IsObject()) { cout << "ObjectArray[" << i << "]: "; if(object.HasMember("name") && object["name"].IsString()) { cout << "name=" << object["name"].GetString(); } if(object.HasMember("age") && object["age"].IsInt()) { cout << ", age=" << object["age"].GetInt(); } if(object.HasMember("sex") && object["sex"].IsBool()) { cout << ", sex=" << (object["sex"].GetBool() ? "男" : "女") << endl; } } } } } /** * 最后注意：因为rapidjson不会做安全校验，所以要自己做安全校验，以int整型为例 * “if(object.HasMember("age") && object["age"].IsInt()) {}” * 这句校验很重要，既要校验有该子段，也要校验类型正确，否则会引发程序崩溃 */ } 还有一种解析方法，这是用于事先不知道name的前提之下，遍历读取，如果已知name，建议使用上面，如果不知道name，则使用下面这种方式 //遍历解析 void parse_1() { // 这个是用于遍历json数组，用于不知道name的前提下 string data = "{"name":"qq849635649","age":20,"sex":true}"; rapidjson::Document dom; if(! dom.Parse(data.data()).HasParseError()) { for (rapidjson::Value::ConstMemberIterator iter = dom.MemberBegin(); iter != dom.MemberEnd(); ++iter) { string name = (iter->name).GetString(); const rapidjson::Value& value = iter->value; if(value.IsString()) { cout << name << " : " << value.GetString() << endl; } else if(value.IsInt()) { cout << name << " : " << value.GetInt() << endl; } else if(value.IsBool()) { cout << name << " : " << value.GetBool() << endl; } } } }