基于C语言Socket和SQLite的温湿度传感器数据监控系统

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sqlite3.h>
#include <stdbool.h>
#include <unistd.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <json-c/json.h>

#define DATABASE 'database.db'
#define PORT 5000

struct Status {
    int sid; // 状态ID
    int uid; // 用户ID
    char device_name[10]; // 设备名称
    char device_state[10]; // 设备状态
    char value[10]; // 值
    char mode[10]; // 模式
};

void handleClientRequest(int clientSocket); // 处理客户端请求
void handleTemperatureHumidity(int clientSocket, int uid); // 处理温度湿度请求
void sendResponse(int clientSocket, const char* response); // 发送响应
char* getAdvice(int temperature, int humidity); // 获取建议

int main() {
    int serverSocket, clientSocket;
    struct sockaddr_in serverAddress, clientAddress;
    socklen_t clientAddressLength = sizeof(clientAddress);

    // 创建套接字
    serverSocket = socket(AF_INET, SOCK_STREAM, 0);
    if (serverSocket < 0) {
        perror('创建套接字出错');
        exit(1);
    }

    // 设置服务器地址
    serverAddress.sin_family = AF_INET;
    serverAddress.sin_addr.s_addr = INADDR_ANY;
    serverAddress.sin_port = htons(PORT);

    // 将套接字绑定到指定的地址和端口
    if (bind(serverSocket, (struct sockaddr*)&serverAddress, sizeof(serverAddress)) < 0) {
        perror('绑定套接字出错');
        exit(1);
    }

    // 监听传入连接
    if (listen(serverSocket, 5) < 0) {
        perror('监听连接出错');
        exit(1);
    }

    printf('服务器已启动。正在监听端口 %d...\n', PORT);

    while (true) {
        // 接受客户端连接
        clientSocket = accept(serverSocket, (struct sockaddr*)&clientAddress, &clientAddressLength);
        if (clientSocket < 0) {
            perror('接受连接出错');
            exit(1);
        }

        printf('客户端已连接，来自 %s:%d\n', inet_ntoa(clientAddress.sin_addr), ntohs(clientAddress.sin_port));

        // 处理客户端请求
        handleClientRequest(clientSocket);

        // 关闭客户端连接
        close(clientSocket);
        printf('客户端已断开连接\n');
    }

    // 关闭服务器套接字
    close(serverSocket);

    return 0;
}

void handleClientRequest(int clientSocket) {
    char buffer[1024];
    int bytesRead = read(clientSocket, buffer, sizeof(buffer));
    if (bytesRead < 0) {
        perror('从套接字读取数据出错');
        exit(1);
    }

    // 解析JSON请求
    struct json_object* jsonRequest = json_tokener_parse(buffer);
    if (jsonRequest == NULL) {
        perror('解析JSON出错');
        exit(1);
    }

    // 从JSON请求中获取用户ID
    struct json_object* jsonUserID;
    json_object_object_get_ex(jsonRequest, 'userid', &jsonUserID);
    int uid = json_object_get_int(jsonUserID);

    // 处理温度湿度请求
    handleTemperatureHumidity(clientSocket, uid);

    // 清理资源
    json_object_put(jsonRequest);
}

void handleTemperatureHumidity(int clientSocket, int uid) {
    sqlite3* db;
    int rc = sqlite3_open(DATABASE, &db);
    if (rc != SQLITE_OK) {
        perror('打开数据库出错');
        exit(1);
    }

    char query[100];
    snprintf(query, sizeof(query), 'SELECT * FROM Status WHERE uid = %d', uid);

    sqlite3_stmt* stmt;
    rc = sqlite3_prepare_v2(db, query, -1, &stmt, 0);
    if (rc != SQLITE_OK) {
        perror('准备SQL语句出错');
        exit(1);
    }

    // 获取用户的最新温度和湿度值
    int temperature = 0;
    int humidity = 0;

    while (sqlite3_step(stmt) == SQLITE_ROW) {
        struct Status status;
        status.sid = sqlite3_column_int(stmt, 0);
        status.uid = sqlite3_column_int(stmt, 1);
        strcpy(status.device_name, (char*)sqlite3_column_text(stmt, 2));
        strcpy(status.device_state, (char*)sqlite3_column_text(stmt, 3));
        strcpy(status.value, (char*)sqlite3_column_text(stmt, 4));
        strcpy(status.mode, (char*)sqlite3_column_text(stmt, 5));

        if (strcmp(status.device_name, 'Temperature') == 0) {
            temperature = atoi(status.value);
        } else if (strcmp(status.device_name, 'Humidity') == 0) {
            humidity = atoi(status.value);
        }
    }

    // 根据温度和湿度值获取建议
    char* advice = getAdvice(temperature, humidity);

    // 将建议发送给客户端
    sendResponse(clientSocket, advice);

    // 清理资源
    sqlite3_finalize(stmt);
    sqlite3_close(db);
}

void sendResponse(int clientSocket, const char* response) {
    int bytesWritten = write(clientSocket, response, strlen(response));
    if (bytesWritten < 0) {
        perror('写入套接字出错');
        exit(1);
    }
}

char* getAdvice(int temperature, int humidity) {
    char* advice = (char*)malloc(100);

    if (temperature < 24) {
        snprintf(advice, 100, '温度过低，请将温度调高至 26°C。');
    } else if (humidity < 40 || humidity > 70) {
        snprintf(advice, 100, '湿度过高或过低，请调整湿度水平。');
    } else {
        snprintf(advice, 100, '暂无建议。');
    }

    return advice;
}