基于C++怎么使用neo4j的http api？

Question

参考文档如https://neo4j.com/docs/http-api/current/actions/
java，python的接口容易找到，但是C++的接口不太好用，看到neo4j有http api，这个能完全跨平台，所以决定使用。但是这个官方文档和网上文档很少找到完整的C++通过http api使用neo4j的例子。请大伙儿给个简单的实例启发下我？目前不考虑很高的性能。

Answer 1

以下是一个简单的 C++ 示例代码，它通过 HTTP API 与 Neo4j 数据库进行交互。在这个示例中，我们使用了 C++ 的 Boost 库来处理 HTTP 请求和响应，同时使用了 RapidJSON 库来解析 JSON 数据。
在开始之前，请确保已经安装了 Boost 和 RapidJSON 库，以及可以访问 Neo4j 数据库的 HTTP API。

#include <iostream>
#include <boost/asio.hpp>
#include <boost/property_tree/ptree.hpp>
#include <boost/property_tree/json_parser.hpp>
#include <rapidjson/document.h>
#include <rapidjson/stringbuffer.h>
#include <rapidjson/writer.h>

using namespace boost::asio;
using boost::asio::ip::tcp;
using boost::property_tree::ptree;
using boost::property_tree::read_json;
using boost::property_tree::write_json;
using rapidjson::Document;
using rapidjson::Value;
using rapidjson::StringBuffer;
using rapidjson::Writer;

std::string send_request(const std::string& request)
{
    io_service io_service;
    tcp::resolver resolver(io_service);
    tcp::resolver::query query("localhost", "7474");
    tcp::socket socket(io_service);
    connect(socket, resolver.resolve(query));

    boost::asio::streambuf request_buf;
    std::ostream request_stream(&request_buf);
    request_stream << "POST /db/data/transaction/commit HTTP/1.1\r\n";
    request_stream << "Host: localhost\r\n";
    request_stream << "Accept: application/json; charset=UTF-8\r\n";
    request_stream << "Content-Type: application/json\r\n";
    request_stream << "Content-Length: " << request.length() << "\r\n";
    request_stream << "\r\n";
    request_stream << request;

    write(socket, request_buf);

    boost::asio::streambuf response_buf;
    boost::asio::read_until(socket, response_buf, "\r\n");
    std::istream response_stream(&response_buf);
    std::string http_version;
    response_stream >> http_version;
    unsigned int status_code;
    response_stream >> status_code;
    std::string status_message;
    std::getline(response_stream, status_message);

    boost::asio::read_until(socket, response_buf, "\r\n\r\n");

    std::stringstream ss;
    ss << &response_buf;
    std::string headers = ss.str();

    boost::asio::streambuf::const_buffers_type cbt = response_buf.data();
    std::string content(boost::asio::buffers_begin(cbt),
                        boost::asio::buffers_end(cbt));

    return content;
}

int main()
{
    // 构造 Neo4j 查询语句
    Value statement(Value::kObjectType);
    statement.AddMember("statement", "MATCH (n) RETURN n LIMIT 1", allocator);
    Value statements(Value::kArrayType);
    statements.PushBack(statement, allocator);
    Value payload(Value::kObjectType);
    payload.AddMember("statements", statements, allocator);

    StringBuffer sb;
    Writer<StringBuffer> writer(sb);
    payload.Accept(writer);
    std::string payload_str = sb.GetString();

    // 发送 HTTP 请求
    std::string response_str = send_request(payload_str);

    // 解析 JSON 响应
    Document response;
    response.Parse(response_str.c_str());

    Value& result = response["results"][0]["data"][0]["row"][0];

    // 输出查询结果
    std::cout << result.GetString() << std::endl;

    return 0;
}