开源代码地址 github:https://github.com/open-source-parsers/jsoncpp
使用的时候直接包含.h和.cpp到项目中，也可以编译成lib库来使用。
json简单字符串解析:
1 //简单Json
2 void Config1()
3 {
4 Json::Value root;
5 Json::Reader reader;
6 std::string str = "{"ip":"127.0.0.1","port":"8080"}";
7 //
8 if (!reader.parse(str, root))
9 {
10 //error
11 }
12 std::ofstream out;
13 out.open("config1.json", std::ios::binary);
14 if (out.fail())
15 {
16 //error
17 }
18 Json::StyledStreamWriter sswriter;
19 sswriter.write(out, root);
20 out.close();
21 }
生成：
{
"ip" : "127.0.0.1",
"port" : "8080"
}
Json嵌套数组，嵌套Json,数组可以通过下标来访问。
//数组Json
//嵌套json
void Config2()
{
Json::Value root;
Json::Reader reader;
//
root["name"] = Json::Value("karllen");
root["age"] = Json::Value("24");
//adress
Json::Value adrress;
adrress["province"] = "浙江";
adrress["city"] = "杭州";
adrress["district"] = "滨江区";
root["address"] = adrress;
//hoby array
Json::Value hobby;
hobby.append(Json::Value("足球"));
hobby.append(Json::Value("篮球"));
hobby.append(Json::Value("乒乓球"));
root["hobby"] = hobby;
//
Json::Value education, education1, education2, education3;
education1["school"] = Json::Value("大学");
education1["period"] = Json::Value("2012-09-01~2016-06-01");
education1["address"] = Json::Value("武汉");
//
education2["school"] = Json::Value("高中");
education2["period"] = Json::Value("2009-09-01~2012-06-01");
education2["address"] = Json::Value("山东");
//
education3["school"] = Json::Value("初中");
education3["period"] = Json::Value("2006-09-01~2009-06-01");
education3["address"] = Json::Value("山东");
//
education.append(education1);
education.append(education2);
education.append(education3);
root["education"] = education;
//
std::ofstream out;
out.open("config2.json", std::ios::binary);
if (out.fail())
{
//error
}
Json::StyledStreamWriter sswriter;
sswriter.write(out, root);
out.close();
}
生成： 生成的Json由name，age，adress，education，hobby组成，address则是嵌套了一个json格式，education是嵌套了一个Json数组，
数组有三个Json标示教育阶段，hobby则是嵌套了一个数组，直接标示了内容。如下：
1 {
2 "address" :
3 {
4 "city" : "杭州",
5 "district" : "滨江区",
6 "province" : "浙江"
7 },
8 "age" : "24",
9 "education" :
10 [
11 {
12 "address" : "武汉",
13 "period" : "2012-09-01~2016-06-01",
14 "school" : "大学"
15 },
16 {
17 "address" : "山东",
18 "period" : "2009-09-01~2012-06-01",
19 "school" : "高中"
20 },
21 {
22 "address" : "山东",
23 "period" : "2006-09-01~2009-06-01",
24 "school" : "初中"
25 }
26 ],
27 "hobby" : [ "足球", "篮球", "乒乓球" ],
28 "name" : "karllen"
29 }
解析上面的Json文件
1 //Json读取
2 //
3 void Config3()
4 {
5 std::ifstream ins;
6 ins.open("config2.json", std::ios::binary);
7 if(ins.fail())
8 {
9 //error
10 }
11 Json::Value root;
12 Json::Reader reader;
13 reader.parse(ins, root);
14 ins.close();
15 //
16 std::vector<std::string> vecStrJson;
17
18 vecStrJson.push_back(root["name"].asString());
19 vecStrJson.push_back(root["age"].asString());
20
21 auto size = root["hobby"].size();
22 for (auto j = 0; j < size; j++)
23 {
24 vecStrJson.push_back(root["hobby"][j].asString());
25 }
26
27 Json::Value address = root["address"];
28 vecStrJson.push_back(address["province"].asString());
29 vecStrJson.push_back(address["city"].asString());
30 vecStrJson.push_back(address["district"].asString());
31
32 Json::Value education = root["education"];
33 size = education.size();
34 for (auto i = 0; i < size; i++)
35 {
36 vecStrJson.push_back(education[i]["school"].asString());
37 vecStrJson.push_back(education[i]["period"].asString());
38 vecStrJson.push_back(education[i]["address"].asString());
39 }
40 }
将所有的Json值都存到了vecStrJson中
