HarmonyOS 网络应用开发 原创
@toc
1.UDP客户端
1.1 UDP协议相关API介绍
socket.h接口简介:
这个socket.h中包含声明UDP协议相关接口函数。
| 接口名 | 功能描述 | 
|---|---|
| socket | 创建套接字 | 
| sendto | 将数据由指定的socket发送到远端主机 | 
| recvfrom | 从远端主机接收UDP数据 | 
| close | 关闭套接字 | 
1.2 UDP客户端创建流程介绍

1.3 实现UDP客户端
打开“D3_iot_udp_client”工程的udp_client_demo.c文件,可在代码中查看实现UDP客户端的代码
static void UDPClientTask(void)
{
    //服务器的地址信息
    struct sockaddr_in send_addr;
    socklen_t addr_length = sizeof(send_addr);
    char recvBuf[512];
    //连接Wifi
    WifiConnect("TP-LINK_65A8", "0987654321");
    //创建socket
    if ((sock_fd = socket(AF_INET, SOCK_DGRAM, 0)) == -1)
    {
        perror("create socket failed!\r\n");
        exit(1);
    }
    //初始化预连接的服务端地址
    send_addr.sin_family = AF_INET;
    send_addr.sin_port = htons(_PROT_);
    send_addr.sin_addr.s_addr = inet_addr("192.168.0.175");
    addr_length = sizeof(send_addr);
    //总计发送 count 次数据
    while (1)
    {
        bzero(recvBuf, sizeof(recvBuf));
        //发送数据到服务远端
        sendto(sock_fd, send_data, strlen(send_data), 0, (struct sockaddr *)&send_addr, addr_length);
        //线程休眠一段时间
        sleep(10);
        //接收服务端返回的字符串
        recvfrom(sock_fd, recvBuf, sizeof(recvBuf), 0, (struct sockaddr *)&send_addr, &addr_length);
        printf("%s:%d=>%s\n", inet_ntoa(send_addr.sin_addr), ntohs(send_addr.sin_port), recvBuf);
    }
    //关闭这个 socket
    closesocket(sock_fd);
}
ip地址要改为电脑的ip地址
 
代码讲解过程见:
https://www.bilibili.com/video/BV1tv411b7SA?p=10&share_source=copy_web&vd_source=8f1cf1d7278a65d1271a6ccbd8891dc6 P25
2.TCP服务端
2.1 TCP协议相关API介绍
socket.h接口简介:
这个socket.h中包含声明TCP协议相关接口函数。
| 接口名 | 功能描述 | 
|---|---|
| socket | 创建套接字 | 
| bind | 为套接字关联了一个相应的地址与端口号 | 
| listen | 将套接字设置为监听模式 | 
| accept | 接受套接字上新的连接 | 
| recv | 接收数据 | 
| send | 发送数据 | 
| close | 关闭套接字 | 
2.2 TCP服务端创建流程介绍

2.3 实现TCP服务端
打开“D4_iot_tcp_server”工程的tcp_server_demo.c文件,可以查看实现TCP服务的代码。
 
	//创建socket
	if ((sock_fd = socket(AF_INET, SOCK_STREAM, 0)) == -1)
	{
		perror("socket is error\r\n");
		exit(1);
	}
	bzero(&server_sock, sizeof(server_sock));
	server_sock.sin_family = AF_INET;
	server_sock.sin_addr.s_addr = htonl(INADDR_ANY);
	server_sock.sin_port = htons(_PROT_);
	//调用bind函数绑定socket和地址
	if (bind(sock_fd, (struct sockaddr *)&server_sock, sizeof(struct sockaddr)) == -1)
	{
		perror("bind is error\r\n");
		exit(1);
	}
	//调用listen函数监听(指定port监听)
	if (listen(sock_fd, TCP_BACKLOG) == -1)
	{
		perror("listen is error\r\n");
		exit(1);
	}
	printf("start accept\n");
 
代码讲解过程见:
https://www.bilibili.com/video/BV1tv411b7SA?p=10&share_source=copy_web&vd_source=8f1cf1d7278a65d1271a6ccbd8891dc6 P26
3.TCP客户端
3.1 TCP协议相关API介绍
socket.h接口简介:
这个socket.h中包含声明TCP协议相关接口函数。
| 接口名 | 功能描述 | 
|---|---|
| socket | 创建套接字 | 
| connect | 连接到指定的主机 | 
| send | 发送数据 | 
| recv | 接收数据 | 
| close | 关闭套接字 | 
3.2 TCP客户端创建流程介绍

3.3 实现TCP客户端
打开“D3_iot_udp_client”工程的udp_client_demo.c文件,修改部分代码即可实现TCP客户端。
 
原代码:
 
static void UDPClientTask(void)
{
    //服务器的地址信息
    struct sockaddr_in send_addr;
    socklen_t addr_length = sizeof(send_addr);
    char recvBuf[512];
    //连接Wifi
    WifiConnect("TP-LINK_65A8", "0987654321");
    //创建socket
    if ((sock_fd = socket(AF_INET, SOCK_DGRAM, 0)) == -1)
    {
        perror("create socket failed!\r\n");
        exit(1);
    }
    //初始化预连接的服务端地址
    send_addr.sin_family = AF_INET;
    send_addr.sin_port = htons(_PROT_);
    send_addr.sin_addr.s_addr = inet_addr("192.168.0.175");
    addr_length = sizeof(send_addr);
    //总计发送 count 次数据
    while (1)
    {
        bzero(recvBuf, sizeof(recvBuf));
        //发送数据到服务远端
        sendto(sock_fd, send_data, strlen(send_data), 0, (struct sockaddr *)&send_addr, addr_length);
        //线程休眠一段时间
        sleep(10);
        //接收服务端返回的字符串
        recvfrom(sock_fd, recvBuf, sizeof(recvBuf), 0, (struct sockaddr *)&send_addr, &addr_length);
        printf("%s:%d=>%s\n", inet_ntoa(send_addr.sin_addr), ntohs(send_addr.sin_port), recvBuf);
    }
    //关闭这个 socket
    closesocket(sock_fd);
}
修改后代码:
 
static const char *send_data = "Hello! I'm BearPi-HM_Nano TCP Client!\r\n";
static void TCPClientTask(void)
{
    //服务器的地址信息
    struct sockaddr_in send_addr;
    socklen_t addr_length = sizeof(send_addr);
    char recvBuf[512];
    //连接Wifi
    WifiConnect("TP-LINK_65A8", "0987654321");
    //创建socket
    if ((sock_fd = socket(AF_INET, SOCK_STREAM, 0)) == -1)
    {
        perror("create socket failed!\r\n");
        exit(1);
    }
    //初始化预连接的服务端地址
    send_addr.sin_family = AF_INET;
    send_addr.sin_port = htons(_PROT_);
    send_addr.sin_addr.s_addr = inet_addr("192.168.0.175");
    addr_length = sizeof(send_addr);
    connect(sock_fd,(struct sockaddr *)&send_addr,addr_length)
    //总计发送 count 次数据
    while (1)
    {
        bzero(recvBuf, sizeof(recvBuf));
        //发送数据到服务远端
        send(sock_fd, send_data, strlen(send_data), 0);
        //线程休眠一段时间
        sleep(10);
        //接收服务端返回的字符串
        recv(sock_fd, recvBuf, sizeof(recvBuf), 0);
        printf("%s:%d=>%s\n", inet_ntoa(send_addr.sin_addr), ntohs(send_addr.sin_port), recvBuf);
    }
    //关闭这个 socket
    closesocket(sock_fd);
}
static void TCPClientDemo(void)
{
    osThreadAttr_t attr;
    attr.name = "TCPClientTask";
    attr.attr_bits = 0U;
    attr.cb_mem = NULL;
    attr.cb_size = 0U;
    attr.stack_mem = NULL;
    attr.stack_size = 10240;
    attr.priority = osPriorityNormal;
    if (osThreadNew((osThreadFunc_t)TCPClientTask, NULL, &attr) == NULL)
    {
        printf("[TCPClientDemo] Falied to create TCPClientTask!\n");
    }
}
APP_FEATURE_INIT(TCPClientDemo);
 
代码讲解过程见:
https://www.bilibili.com/video/BV1tv411b7SA?p=10&share_source=copy_web&vd_source=8f1cf1d7278a65d1271a6ccbd8891dc6 P27
4. UDP服务端
4.1 UDP协议相关API介绍
socket.h接口简介:
这个socket.h中包含声明UDP协议相关接口函数。
| 接口名 | 功能描述 | 
|---|---|
| socket | 创建套接字 | 
| bind | 将ip和端口绑定到嵌套字 | 
| sendto | 将数据由指定的socket发送对方主机 | 
| recvfrom | 从指定主机接收UDP数据 | 
| close | 关闭套接字 | 
4.2 UDP服务端创建流程介绍

4.3 实现UDP服务端
打开“D4_iot_tcp_server”工程的tcp_server_demo.c文件,修改部分代码即可实现UDP服务端。
 
原代码:
 
static void TCPServerTask(void)
{
	//服务端地址信息
	struct sockaddr_in server_sock;
	//客户端地址信息
	struct sockaddr_in client_sock;
	int sin_size;
	struct sockaddr_in *cli_addr;
	//连接Wifi
	WifiConnect("TP-LINK_65A8", "0987654321");
	//创建socket
	if ((sock_fd = socket(AF_INET, SOCK_STREAM, 0)) == -1)
	{
		perror("socket is error\r\n");
		exit(1);
	}
	bzero(&server_sock, sizeof(server_sock));
	server_sock.sin_family = AF_INET;
	server_sock.sin_addr.s_addr = htonl(INADDR_ANY);
	server_sock.sin_port = htons(_PROT_);
	//调用bind函数绑定socket和地址
	if (bind(sock_fd, (struct sockaddr *)&server_sock, sizeof(struct sockaddr)) == -1)
	{
		perror("bind is error\r\n");
		exit(1);
	}
	//调用listen函数监听(指定port监听)
	if (listen(sock_fd, TCP_BACKLOG) == -1)
	{
		perror("listen is error\r\n");
		exit(1);
	}
	printf("start accept\n");
	//调用accept函数从队列中
	while (1)
	{
		sin_size = sizeof(struct sockaddr_in);
		if ((new_fd = accept(sock_fd, (struct sockaddr *)&client_sock, (socklen_t *)&sin_size)) == -1)
		{
			perror("accept");
			continue;
		}
		cli_addr = malloc(sizeof(struct sockaddr));
		printf("accept addr\r\n");
		if (cli_addr != NULL)
		{
			memcpy(cli_addr, &client_sock, sizeof(struct sockaddr));
		}
		//处理目标
		ssize_t ret;
		while (1)
		{
			if ((ret = recv(new_fd, recvbuf, sizeof(recvbuf), 0)) == -1)
			{
				printf("recv error \r\n");
			}
			printf("recv :%s\r\n", recvbuf);
			sleep(2);
			if ((ret = send(new_fd, buf, strlen(buf) + 1, 0)) == -1)
			{
				perror("send : ");
			}
			sleep(2);
		}
		close(new_fd);
	}
}
修改后代码:
 
//在sock_fd 进行监听,在 new_fd 接收新的链接
int sock_fd, new_fd;
char recvbuf[512];
char *buf = "Hello! I'm BearPi-HM_Nano UDP Server!";
static void UDPServerTask(void)
{
	//服务端地址信息
	struct sockaddr_in server_sock;
	//客户端地址信息
	struct sockaddr_in client_sock;
	int sin_size;
	struct sockaddr_in *cli_addr;
	//连接Wifi
	WifiConnect("TP-LINK_65A8", "0987654321");
	//创建socket
	if ((sock_fd = socket(AF_INET, SOCK_DGRAM, 0)) == -1)
	{
		perror("socket is error\r\n");
		exit(1);
	}
	bzero(&server_sock, sizeof(server_sock));
	server_sock.sin_family = AF_INET;
	server_sock.sin_addr.s_addr = htonl(INADDR_ANY);
	server_sock.sin_port = htons(_PROT_);
	//调用bind函数绑定socket和地址
	if (bind(sock_fd, (struct sockaddr *)&server_sock, sizeof(struct sockaddr)) == -1)
	{
		perror("bind is error\r\n");
		exit(1);
	}
	//调用listen函数监听(指定port监听)
	//if (listen(sock_fd, TCP_BACKLOG) == -1)
	//{
	//	perror("listen is error\r\n");
	//	exit(1);
	//}
	//printf("start accept\n");
	//调用accept函数从队列中
	while (1)
	{
		sin_size = sizeof(struct sockaddr_in);
	//	if ((new_fd = accept(sock_fd, (struct sockaddr *)&client_sock, (socklen_t *)&sin_size)) == -1)
	//	{
	//		perror("accept");
	//		continue;
	//	}
	//	cli_addr = malloc(sizeof(struct sockaddr));
	//	printf("accept addr\r\n");
	//	if (cli_addr != NULL)
	//	{
	//		memcpy(cli_addr, &client_sock, sizeof(struct sockaddr));
	//	}
		//处理目标
		ssize_t ret;
		while (1)
		{
			if ((ret = recvfrom(sock_fd, recvbuf, sizeof(recvbuf), 0,(struct sockaddr *)&client_sock, (socklen_t *)&sin_size)) == -1)
			{
				printf("recv error \r\n");
			}
			printf("recv :%s\r\n", recvbuf);
			//sleep(2);
			if ((ret = sendto(sock_fd, buf, strlen(buf) + 1, 0,(struct sockaddr *)&client_sock,sizeof(client_sock))) == -1)
			{
				perror("send : ");
			}
			//sleep(2);
		}
		close(new_fd);
	}
}
static void UDPServerDemo(void)
{
	osThreadAttr_t attr;
	attr.name = "UDPServerTask";
	attr.attr_bits = 0U;
	attr.cb_mem = NULL;
	attr.cb_size = 0U;
	attr.stack_mem = NULL;
	attr.stack_size = 10240;
	attr.priority = osPriorityNormal;
	if (osThreadNew((osThreadFunc_t)UDPServerTask, NULL, &attr) == NULL)
	{
		printf("[UDPServerDemo] Falied to create UDPServerTask!\n");
	}
}
APP_FEATURE_INIT(UDPServerDemo);
 
代码讲解过程见:
https://www.bilibili.com/video/BV1tv411b7SA?p=10&share_source=copy_web&vd_source=8f1cf1d7278a65d1271a6ccbd8891dc6 P28
5. MQTT客户端
5.1 MQTT介绍
MOTT (Message Queuing Telemetry Transport,消息队列遥测传输协议),是一种基于发布/订阅(publish/subscribe)模式的"轻量级"通讯协议,该协议构建于TCP/IP协议上,由IBM在1999年发布。
 

 
Paho是IBM在2011年建立的Eclipse开源项目,该项目包含以C、Java、Python、Javascript等语言编写的可用客户端。
 
嵌入式c语言客户端开源地址:
https://github.com/eclipse/paho.mqtt.embedded-c
5.2 Paho MQTT文件目录介绍

 
- MQTTClient:封装MQTTPacket生成的高级别C++客户端程序。
 - MQTTClient-C:封装MQTTPacket生成的高级别C客户端程序
- samples目录提供FreeRTOS和linux两个例程,分别支持FreeRTOS和Linux系统。
 - src目录提供MQTTClient的代码实现能力,以及用于移植到对应平台的网络驱动
 
 - MQTTPacket:提供MQTT数据包的序列化与反序列化,以及部分辅助函数。
 
5.3 如何使用Paho MQTT
在MQTTClient.h中包含声明Paho MQTT相关接口函数。
| 接口名 | 功能描述 | 
|---|---|
| MQTTClientlnit | 创建一个客户端对象 | 
| MQTTConnect | 发送MQTT连接数据包 | 
| MQTTConnectWithResults | 发送MQTT连接数据包并等待返回 | 
| MQTTPublish | 发送MQTT发布数据包 | 
| MQTTSetMessageHandler | 发送每个topic消息处理函数 | 
| MQTTSubscribe | 发送MQTT订阅数据包 | 
| MQTTSubscribeWithResults | 发送MQTT订阅数据包并等待返回结果 | 
| MQTTUnsubscribe | 发送MQTT取消数据包 | 
| MQTTDisconnect | 发送MQTT断开连接数据包并关闭连接 | 
5.4 实现MQTT客户端
打开“D5_iot_mqtt”工程的iot_mqtt.c文件,查看实现MQTT客户端的代码。
 
	NetworkConnect(&network, "192.168.0.176", 1883);
	printf("MQTTClientInit  ...\n");
	MQTTClientInit(&client, &network, 2000, sendBuf, sizeof(sendBuf), readBuf, sizeof(readBuf));
	MQTTString clientId = MQTTString_initializer;
	clientId.cstring = "bearpi";
	MQTTPacket_connectData data = MQTTPacket_connectData_initializer;
  	data.clientID          = clientId;
	data.willFlag          = 0;
	data.MQTTVersion       = 3;
	data.keepAliveInterval = 0;
	data.cleansession      = 1;
	printf("MQTTConnect  ...\n");
	rc = MQTTConnect(&client, &data);
	if (rc != 0) {
		printf("MQTTConnect: %d\n", rc);
		NetworkDisconnect(&network);
		MQTTDisconnect(&client);
		osDelay(200);
		goto begin;
	}
	printf("MQTTSubscribe  ...\n");
	rc = MQTTSubscribe(&client, "substopic", 2, messageArrived);
	if (rc != 0) {
		printf("MQTTSubscribe: %d\n", rc);
		osDelay(200);
		goto begin;
	}
	while (++count)
	{
		MQTTMessage message;
		char payload[30];
		message.qos = 2;
		message.retained = 0;
		message.payload = payload;
		sprintf(payload, "message number %d", count);
		message.payloadlen = strlen(payload);
		if ((rc = MQTTPublish(&client, "pubtopic", &message)) != 0){
			printf("Return code from MQTT publish is %d\n", rc);
			NetworkDisconnect(&network);
			MQTTDisconnect(&client);
			goto begin;
		}
		osDelay(50);	
	}
 
代码讲解过程见:
https://www.bilibili.com/video/BV1tv411b7SA?p=10&share_source=copy_web&vd_source=8f1cf1d7278a65d1271a6ccbd8891dc6 P29
 
本部分代码也做了一些更新,如果发现代码不一样的话,可以去gitee同步一下




















