• 日期: 2028-01-23
  • 标签: 常规

#include <stdio.h> #include <stdlib.h> #include <string.h> #include <unistd.h> #include <sys/socket.h> #include <arpa/inet.h> #include <sqlite3.h> #include <pthread.h> #include <signal.h> #include 'server.h'

int main() { // 创建套接字 int sockfd = socket(AF_INET, SOCK_STREAM, 0); if (sockfd == -1) { perror('socket'); return 1; }

// 设置服务器地址
struct sockaddr_in server_addr;
server_addr.sin_family = AF_INET;
server_addr.sin_addr.s_addr = INADDR_ANY;
server_addr.sin_port = htons(12345);

// 绑定套接字到服务器地址
if (bind(sockfd, (struct sockaddr *)&server_addr, sizeof(server_addr)) == -1) {
    perror('bind');
    close(sockfd);
    return 1;
}

// 监听连接请求
if (listen(sockfd, 5) == -1) {
    perror('listen');
    close(sockfd);
    return 1;
}

// 打开数据库
sqlite3 *db;
int rc = sqlite3_open('..SmartHome/Client/Smarthome_Client/database/database.db', &db);
if (rc != SQLITE_OK) {
    fprintf(stderr, 'Failed to open database: %s\n', sqlite3_errmsg(db));
    close(sockfd);
    return 1;
}

// 初始化服务器上下文
ServerContext context;
context.sockfd = sockfd;
context.client_addr_len = sizeof(context.client_addr);
context.db = db;
pthread_mutex_init(&context.mutex, NULL);


// 处理客户端连接
handleClientConnection(&context);

// 关闭数据库
rc = sqlite3_close(db);
if (rc != SQLITE_OK) {
    fprintf(stderr, 'Failed to close database: %s\n', sqlite3_errmsg(db));
    return 1;
}

// 关闭套接字
if (close(sockfd) == -1) {
    perror('close');
    return 1;
}

pthread_mutex_destroy(&context.mutex);
return 0;

}

#include 'server.h'

// 处理客户端请求 void handleClientRequest(ServerContext *context) { char buffer[MAX_BUFFER_SIZE]; int userid;

// 接收客户端发送的userid
ssize_t recvSize = recv(context->sockfd, &userid, sizeof(int), 0);
if (recvSize == -1) {
    perror('recv');
    return;
}

// 查询数据库获取设备状态信息
char sql[100];
snprintf(sql, sizeof(sql), 'SELECT * FROM Status WHERE uid = %d', userid);
sqlite3_stmt *stmt;
int rc = sqlite3_prepare_v2(context->db, sql, -1, &stmt, NULL);
if (rc != SQLITE_OK) {
    fprintf(stderr, 'Failed to execute statement: %s\n', sqlite3_errmsg(context->db));
    return;
}

Status status;
rc = sqlite3_step(stmt);
if (rc == SQLITE_ROW) {
    status.uid = sqlite3_column_int(stmt, 1);
    strncpy(status.device_name, sqlite3_column_text(stmt, 2), sizeof(status.device_name)-1);
    strncpy(status.device_state, sqlite3_column_text(stmt, 3), sizeof(status.device_state)-1);
    strncpy(status.value, sqlite3_column_text(stmt, 4), sizeof(status.value)-1);
    strncpy(status.mode, sqlite3_column_text(stmt, 5), sizeof(status.mode)-1);
} else if (rc == SQLITE_DONE) {
    fprintf(stderr, 'No data found for user %d\n', userid);
    sqlite3_finalize(stmt);
    return;
} else {
    fprintf(stderr, 'Failed to execute statement: %s\n', sqlite3_errmsg(context->db));
    sqlite3_finalize(stmt);
    return;
}
sqlite3_finalize(stmt);

// 分析设备状态并生成建议
char suggestion[MAX_BUFFER_SIZE];
if (strcmp(status.device_name, '空调') == 0) {
    int temperature = atoi(status.value);
    if (temperature < 24) {
        snprintf(suggestion, sizeof(suggestion), '空调温度过低，建议提高温度至26℃');
    } else {
        snprintf(suggestion, sizeof(suggestion), '空调温度正常');
    }
} else if (strcmp(status.device_name, '加湿器') == 0) {
    int humidity = atoi(status.value);
    if (humidity < 40 || humidity > 70) {
        snprintf(suggestion, sizeof(suggestion), '加湿器湿度过高或过低，建议调整加湿器湿度');
    } else {
        snprintf(suggestion, sizeof(suggestion), '加湿器湿度正常');
    }
} else {
    snprintf(suggestion, sizeof(suggestion), '设备状态未知');
}

// 向客户端发送建议
ssize_t sendSize = send(context->sockfd, suggestion, strlen(suggestion), 0);
if (sendSize == -1) {
    perror('send');
    return;
}

}

// 处理客户端连接 void *handleClientConnection(void *arg) { ServerContext *context = (ServerContext *)arg; int clientSockfd = accept(context->sockfd, (struct sockaddr *)&context->client_addr, &context->client_addr_len); if (clientSockfd == -1) { perror('accept'); return NULL; }

context->sockfd = clientSockfd;
handleClientRequest(context);

close(clientSockfd);
return NULL;

}

#ifndef SERVER_H #define SERVER_H

#include <stdio.h> #include <stdlib.h> #include <string.h> #include <unistd.h> #include <sys/socket.h> #include <arpa/inet.h> #include <sqlite3.h> #include <pthread.h> #include <signal.h>

#define MAX_BUFFER_SIZE 1024

// 设备状态结构体 typedef struct { int uid; char device_name[10]; char device_state[10]; char value[10]; char mode[10]; } Status;

// 服务器上下文结构体，包含服务器相关信息 typedef struct { int sockfd; struct sockaddr_in client_addr; socklen_t client_addr_len; sqlite3 *db; pthread_mutex_t mutex; } ServerContext;

// 处理客户端请求 void handleClientRequest(ServerContext *context);

// 处理客户端连接 void *handleClientConnection(void *arg);

#endif

#include 'procession.h' #include 'ui_procession.h' #include #include

Procession::Procession(int userid,QWidget *parent) : QWidget(parent), ui(new Ui::Procession), userid(userid) { ui->setupUi(this); processionWidget(); m_socket = new QTcpSocket(this); connect(ui->connectBtn, &QPushButton::clicked, this, &Procession::on_pushButton_clicked); connect(m_socket, &QTcpSocket::readyRead, this, &Procession::readyRead); connect(m_socket, &QTcpSocket::connected, this, &Procession::connected); connect(m_socket, &QTcpSocket::disconnected,this,&Procession::disconnected); connect(m_socket, QOverloadQAbstractSocket::SocketError::of(&QTcpSocket::error), this, &Procession::displayError); }

Procession::~Procession() { delete ui; }

void Procession::processionWidget() { setWindowTitle('服务器通信'); setAutoFillBackground(true); QPalette palette=this->palette(); QPixmap pixmap(':/user/image/image/net.jpg'); palette.setBrush(QPalette::Window, QBrush(pixmap)); setPalette(palette); setFixedSize(600,400); } void Procession::on_pushButton_clicked() { if (m_socket->state() == QAbstractSocket::ConnectedState) { ui->message->append('已经连接上服务器'); return; }

QString ip = ui->IP->text();
QString port = ui->port->text();

if (ip.isEmpty() || port.isEmpty()) {
    ui->message->clear();
    ui->message->append('请输入有效的IP地址和端口号');
    return;
}

ui->message->clear();
ui->message->append('正在连接中...');
m_socket->connectToHost(ip, static_cast<quint16>(ui->port->text().toInt()));

}

void Procession::connected() { ui->message->append('连接成功'); // 发送userid给服务器 QByteArray block; QDataStream out(&block, QIODevice::WriteOnly); out << this->userid; if (m_socket->write(block) == -1) { ui->message->append('发送userid失败'); m_socket->close(); } }

void Procession::disconnected() { ui->message->append('连接失败'); m_socket->close(); }

void Procession::readyRead() { QByteArray data = m_socket->readAll(); if (data.isEmpty()) { ui->message->append('读取的数据为空'); return; } // 解析服务器返回的数据 QDataStream in(&data, QIODevice::ReadOnly); QString suggestion; in >> suggestion; // 使用重载的 >> 运算符来读取数据 if (in.status() != QDataStream::Ok) { ui->message->append('解析服务器返回的数据失败'); return; } ui->message->append(suggestion); m_socket->close(); }

void Procession::displayError(QAbstractSocket::SocketError error) { QString errorMessage; switch (error) { case QAbstractSocket::ConnectionRefusedError: errorMessage = '连接被拒绝'; break; case QAbstractSocket::RemoteHostClosedError: errorMessage = '远程主机关闭'; break; case QAbstractSocket::HostNotFoundError: errorMessage = '未找到主机'; break; case QAbstractSocket::SocketTimeoutError: errorMessage = '连接超时'; break; case QAbstractSocket::NetworkError: errorMessage = '网络错误'; break; default: errorMessage = '未知错误'; break; } ui->message->append('连接失败：' + errorMessage); } userid等于123，为什么 控制台输出No data found for user 2063597568 如何确认客户端发送的userid是否正确传递给了服务器端。 root@WIN-K3C9KG85CB8:/home/SmartHome/Server# ./main.exec Received userid: 2063597568 No data found for user 2063597568 为什么客户端传过去的userid不是123 但是服务器收到的userid是2063597568内容：根据代码分析，客户端发送的userid是123，但是服务器端接收到的userid是2063597568。这可能是由于数据类型不匹配导致的。在服务器端的recv函数中，接收的是一个int类型的数据，而在客户端的send函数中，发送的是一个QByteArray类型的数据。由于int类型和QByteArray类型不兼容，导致接收到的数据无法正确解析。解决方法是在客户端发送数据之前，将int类型转换为QByteArray类型，然后在服务器端接收数据之后，将QByteArray类型转换为int类型。具体代码如下：

客户端：

// 发送userid给服务器
int userid = 123;
QByteArray block;
QDataStream out(&block, QIODevice::WriteOnly);
out << userid;
if (m_socket->write(block) == -1) {
    ui->message->append('发送userid失败');
    m_socket->close();
}

服务器端：

// 接收客户端发送的userid
int userid;
ssize_t recvSize = recv(context->sockfd, &userid, sizeof(int), 0);
if (recvSize == -1) {
    perror('recv');
    return;
}
userid = ntohl(userid); // 将网络字节序转换为主机字节序

通过将int类型转换为QByteArray类型发送，然后再将QByteArray类型转换为int类型接收，可以确保数据在客户端和服务器端之间正确传递。

C++ SQLite3 服务器：使用套接字接收客户端请求并处理数据库查询

原文地址: https://www.cveoy.top/t/topic/fCgS 著作权归作者所有。请勿转载和采集!

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