银行业务系统（c/s架构、socket网络编程、多线程）

1、功能要求

包括两类用户：管理人员和普通用户（本文只写了普通用户程序）

普通用户功能：登录登出、存取款、转账、查询余额

2、技术要求

要求用到多进程多线程

要求同时允许多个用户操作（因为没有注册账号功能，且只初始化了两个账号信息，所以同时只能允许两个账号在线）

3、程序编写

第一次写C/S架构的程序，很多可能对于其他人来说很简单的问题我之前都没遇到过，所以写的过程中充满了艰辛，主要有几个问题让我困扰好久：

（1）客户端服务器之间的通信，整个socket框架借鉴的网上其他人的博客内容；

（2）技术要求中写道要用多进程多线程，一开始以为两个技术都要用到，纠结了老半天，网上查资料才明白选择一种应该就可以了，好像是因为两个技术同时使用容易出问题，具体也不太明白，我这里使用的多线程，需要注意的是在线程函数中传递参数的问题，具体可看程序或网上其他分析；

（3）socket编程客户端和服务器之间收发数据时，send和recv函数都是传送的一个数据缓冲区（const char FAR *buf），而银行系统中根据不同的操作，发送的数据类型和个数是不一样的，根据网上资料，本文将所有要发送或接受的数据定义在一个结构体中（分别是sendMsg和recvMsg），发送的时候可以直接发送结构体地址信息（sendMsg），且因为数据缓冲区（buf）传送的是字符串，最后一个字符为'\o'，所以发送端的大小必须为（sizeof(sMsg)+1）；在接收数据时，只能将接收到的数据存放在数据缓冲区（buf）中，然后再通过memcpy函数将其转换成对应的结构体（recvMsg），需要注意的是客户端和服务器中的结构体名称虽然可以不一样，但是两个结构体中对应的变量位置一定要相同，因为在发送和接收的时候，memcpy函数只把数据解析到对应位置。

服务器 server.c

#include <sys/types.h>         
#include <sys/socket.h>
#include <string.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <unistd.h>
#include <stdio.h>
#include <signal.h>
#include <pthread.h>


#define SERVER_PORT 8888 //端口号，定义为宏方便以后直接修改
#define BACKLOG     10   //表服务器可以同时监测多少个客户端连接，设置为>0即可


struct accountMsg
{
	//char *name;
	int password;
	int account;
	int balance;//余额
	//bool uCal;//账户类型
};
	
struct accountMsg accountMsg1[10];


struct recvMsg
{
	//char *name;			//户主姓名
	int account;		//账号
	int password;		//密码
	int money;		    //金额
	int uCal;			//账户类型
	int taskID;			//操作任务类型
	
};

//—————————————————————————登录验证—————————————————————————————
int login(int iSocketClient,struct recvMsg rMsg)
{
	int iSendLen;
	int iRecvLen;
	int accessBuf=0;
	printf("____________login ing__________\n");
	int uid;
	for(uid=0;uid<10;uid++)

	{
		if(rMsg.account == accountMsg1[uid].account 
			&& rMsg.password == accountMsg1[uid].password )
		{
			accessBuf = 1;
			break;
		}
	}
	if (accessBuf !=1)
	{
		printf("__________login failed__________\n\n");
	}
	iSendLen = send(iSocketClient, &accessBuf, sizeof(accessBuf), 0);
	if (iSendLen <= 0)
	{
		printf("__________message zend error__________\n\n");
		close(iSocketClient);
		return -1;
	}
	if(accessBuf == 1)
	{
		printf("__________client login succeed!__________\n\n");
		accessBuf=0;
	}
	return uid;
}

//——————————————————————————存钱——————————————————————————
int saveMoney(int iSocketClient,struct recvMsg rMsg,int uid)
{
	printf("___________save Money ing__________\n");
	int iSendLen;
	accountMsg1[uid].balance = accountMsg1[uid].balance + rMsg.money;
	iSendLen = send(iSocketClient, &accountMsg1[uid].balance, sizeof(accountMsg1[uid].balance), 0);
	if (iSendLen <= 0)
	{
		printf("___________save Money failed__________\n\n");
		close(iSocketClient);
		return -1;
	}
	printf("___________save Money succeed__________\n\n");
	return 0;
}

//——————————————————————————取钱—————————————————————————————
int withdrawMoney(int iSocketClient,struct recvMsg rMsg,int uid)
{
	printf("___________withdraw Money ing__________\n");
	int iSendLen;
	int balance;
	balance = accountMsg1[uid].balance - rMsg.money;
	iSendLen = send(iSocketClient, &balance, sizeof(balance), 0);
	if (iSendLen <= 0)
	{
		printf("___________withdraw Money failed__________\n\n");
		close(iSocketClient);
		return -1;
	}
	else if(balance >= 0)
	{
		accountMsg1[uid].balance = balance;
	}
	printf("___________withdraw Money END__________\n\n");
	return 0;
}

//——————————————————————————转账—————————————————————————————
int transferMoney(int iSocketClient,struct recvMsg rMsg,int uid)
{
	printf("___________transfer Money ing__________\n");
	int iSendLen;
	int balance;
	balance = accountMsg1[uid].balance - rMsg.money;
	int tuid;
	for(tuid=0;tuid<10;tuid++)

	{
		//核对转账账号是否存在
		if(rMsg.account == accountMsg1[tuid].account && tuid != uid)
		{	
			break;
		}
	}
	//账号不存在
	if(tuid>=10)
	{
		printf("__________account do not exit_________\n\n");
		balance = -1;
	}
	iSendLen = send(iSocketClient, &balance, sizeof(balance), 0);
	if (iSendLen <= 0)
	{
		printf("___________transfer Money failed__________\n\n");
		close(iSocketClient);
		return -1;
	}
	else if(balance >= 0 && tuid < 10)//send成功后再修改账户余额
	{
		accountMsg1[uid].balance = balance; //登录用户账号余额
		accountMsg1[tuid].balance = accountMsg1[tuid].balance + rMsg.money; //被转账用户账号余额
	}
	printf("___________transfer Money END__________\n\n");
	return 0;
}


int balanceEnquire(int iSocketClient,struct recvMsg rMsg,int uid)
{	
	printf("___________balance Enquire ing__________\n");
	int iSendLen;
	iSendLen = send(iSocketClient, &accountMsg1[uid].balance, sizeof(accountMsg1[uid].balance), 0);
	if (iSendLen <= 0)
	{
		printf("___________balance Enquire failed__________\n\n");
		close(iSocketClient);
		return -1;
	}
	printf("___________balance Enquire succeed__________\n\n");
	return 0;
}


//———————————————————————创建套接字——————————————————————————
int creatSocket()
{
	int iSocketServer;
	iSocketServer = socket(AF_INET, SOCK_STREAM, 0);
	if (-1 == iSocketServer)
	{
		printf("socket error!\n");
		return -1;
	}

	struct sockaddr_in tSocketServerAddr;//服务器地址结构
	
	tSocketServerAddr.sin_family = AF_INET;
	tSocketServerAddr.sin_port   = htons(SERVER_PORT); 
 	tSocketServerAddr.sin_addr.s_addr = INADDR_ANY;
	memset(tSocketServerAddr.sin_zero, 0, 8);
	
	int iRet;
	iRet = bind(iSocketServer, (const struct sockaddr *)&tSocketServerAddr, sizeof(struct sockaddr));
	if (-1 == iRet)
	{
		printf("bind error!\n");
		return -1;
	}
  
	iRet = listen(iSocketServer, BACKLOG);
	if (-1 == iRet)
	{
		printf("listen error!\n");
		return -1;
	}
	return iSocketServer;
}

//——————————————————————线程处理函数——————————————————————————
void *handle_client(void *arg)
{	
    int iSocketClient = *(int*)arg;
	int uid;
	printf("_____________________at handle thread____________________\n");
	while (1)
	{
		printf("____________________waiting client operation...____________________\n\n");
		struct recvMsg rMsg;
		memset(&rMsg,0,sizeof(rMsg));
		char buf[1024]={0};
		int iRecvLen = recv(iSocketClient, buf,1025, 0);
		memcpy(&rMsg,buf,sizeof(rMsg));	
		if (iRecvLen <= 0)
		{
			printf("_________________error recv_______________\n");
			break;
		}
		buf[iRecvLen] = '\0';
		//printf("_____3 rMsg.account:  %d  rMsg.password:  %d  rMsg.taskID: %d___\n",rMsg.account,rMsg.password,rMsg.taskID);	
		switch(rMsg.taskID)
		{
			case 0: uid = login(iSocketClient,rMsg);
					break;
			case 1: saveMoney(iSocketClient,rMsg,uid);
					break;
			case 2: withdrawMoney(iSocketClient,rMsg,uid);
					break;
			case 3: transferMoney(iSocketClient,rMsg,uid); 
					break;
			case 4: balanceEnquire(iSocketClient,rMsg,uid); 
					break;
			default:
					break;					
		 }
	 }
	//close(iSocketClient);
}


int main()
{
	memset(accountMsg1, 0, sizeof(accountMsg1)*10);
	accountMsg1[0].account = 123;
	accountMsg1[0].password = 456;
	accountMsg1[0].balance = 800;
	//accountMsg1[0].uCal = 1;//普通用户
	accountMsg1[1].account = 1212;
	accountMsg1[1].password = 3456;
	accountMsg1[1].balance = 500;
	int iSocketServer;
	iSocketServer=creatSocket();
	if (-1 == iSocketServer)
	{
		printf("create socket failed!\n");
		return -1;
	}
	
	struct sockaddr_in iSocketClientAddr;//客户端地址结构：当客户端来连接时会传过来
	int iAddrLen;
	int iRecvLen;
	printf("____server running,waiting for client conneting...__\n");
		
	while (1)
	{
		iAddrLen = sizeof(struct sockaddr);
		
		int iSocketClient = accept(iSocketServer, (struct sockaddr *)&iSocketClientAddr, &iAddrLen);
		if (-1 != iSocketClient)
		{
			printf("___accepted client message successed!__\n");
			pthread_t pid;
			pthread_create(&pid,NULL,handle_client,&iSocketClient);

			pthread_detach(pid);				
		}	
		//close(iSocketServer);
	}
	close(iSocketServer);
	return 0;
}

客户端 client.c

#include <sys/types.h>        
#include <sys/socket.h>
#include <string.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <unistd.h>
#include <stdio.h>
#include <pthread.h>


#define SERVER_PORT 8888

struct sendMsg
{
	//char *name;		//户主姓名
	int account;		//账号
	int password;		//密码
	int money;		//金额
	int uCal;		//账户类型
	int taskID;		//操作任务类型
	
};


int verify(int iSocketClient,struct sendMsg sMsg) 	//验证密码
{
	printf("_________verify user info ing_______\n\n");
	int iSendLen;
	int iRecvLen;
	iSendLen = send(iSocketClient, (char *)&sMsg, sizeof(sMsg)+1, 0);
	//free(buf);
	if (iSendLen <= 0)
	{
		close(iSocketClient);
		return -1;
	}
	//char accessBuf[20];
	int accessBuf=0;
	iRecvLen = recv(iSocketClient, &accessBuf, sizeof(accessBuf), 0);
	if (iRecvLen <= 0)
	{	
		close(iSocketClient);
		return -1;
	}
	if(0 == accessBuf)
	{
		return -1;
	}
	printf("_________verify user info succeed!_______\n\n");
	return 0;
}

void login(int iSocketClient)
{
	struct sendMsg sMsg;	
	loop0:printf("\n_____Welcome to bank client!_____\n\n");
	memset(&sMsg,0,sizeof(sMsg));
	loop1:printf("Please choose your identity:\n");
	printf("0 Manager		1 User\n");
	scanf("%d",&sMsg.uCal);
	if(1 != sMsg.uCal)
	{
		if(0 != sMsg.uCal)
		{
			printf("identity error! \n");
			goto loop1;
		}
	}		
	loop2:printf("account: ");
	scanf("%d",&sMsg.account);
	printf("password: ");
	scanf("%d",&sMsg.password);
	if(0 != verify(iSocketClient,sMsg))
	{
		printf("account or password error,please relogin! \n");
		goto loop2;
	}
	while(1)
	{
		printf("_____________Welcome to bank client!_____________\n");
		printf("_____________Main Business_____________\n\n");
		printf("1 saveMoney \n2 withdrawMoney \n3 transferMoney \n4 balanceEnquire \n5 exit\n");
		printf("\nPlease enter the business ID:");
		scanf("%d",&sMsg.taskID);
		printf("\n");
		switch(sMsg.taskID)
		{
			case 1: saveMoney(iSocketClient,sMsg);
					break;
			case 2: withdrawMoney(iSocketClient,sMsg);
					break;
			case 3: transferMoney(iSocketClient,sMsg); 
					break;
			case 4: balanceEnquire(iSocketClient,sMsg); 
					break;
			case 5: goto loop0;
					break;
			default:
					break;			
		}
	}
	
}

int balanceEnquire(int iSocketClient,struct sendMsg sMsg)
{	
	int iSendLen;
	int iRecvLen;
	printf("___________balance Enquire ing__________\n\n");	
	
	iSendLen = send(iSocketClient, &sMsg, sizeof(sMsg), 0);
	if (iSendLen <= 0)
	{
		close(iSocketClient);
		return -1;
	}
	
	int balanceBuf;
	iRecvLen = recv(iSocketClient, &balanceBuf, sizeof(balanceBuf), 0);
	if (iRecvLen <= 0)
	{
		close(iSocketClient);
		return -1;
	}
	else
	{
		printf("Your balance is:  %d\n\n",balanceBuf );
	}
	return 0;
}

int saveMoney(int iSocketClient,struct sendMsg sMsg)
{
	int iSendLen;
	int iRecvLen;
	printf("___________save Money ing__________\n\n");	
	printf("please enter the money: ");
	scanf("%d",&sMsg.money);
	
	iSendLen = send(iSocketClient, &sMsg, sizeof(sMsg), 0);
	if (iSendLen <= 0)
	{
		close(iSocketClient);
		return -1;
	}
	
	int balanceBuf;
	iRecvLen = recv(iSocketClient, &balanceBuf, sizeof(balanceBuf), 0);
	if (iRecvLen <= 0)
	{
		close(iSocketClient);
		return -1;
	}
	else
	{
		printf("Save Succeed!\n Your balance is:  %d\n\n",balanceBuf );
	}
	return 0;
}

int withdrawMoney(int iSocketClient,struct sendMsg sMsg)
{
	int iSendLen;
	int iRecvLen;
	printf("___________withdraw Money ing__________\n\n");	
	printf("please enter the money: ");
	scanf("%d",&sMsg.money);
	
	iSendLen = send(iSocketClient, &sMsg, sizeof(sMsg), 0);
	if (iSendLen <= 0)
	{
		close(iSocketClient);
		return -1;
	}
	
	int balanceBuf;
	iRecvLen = recv(iSocketClient, &balanceBuf, sizeof(balanceBuf), 0);
	if (iRecvLen <= 0)
	{
		close(iSocketClient);
		return -1;
	}
	else if(balanceBuf < 0)
	{
		printf("withdraw failed!\n Your balance is not sufficient!\n\n" );
	}
	else
	{
		printf("withdraw Succeed!\n Your balance is:  %d\n\n",balanceBuf );
	}
	return 0;

}

int transferMoney(int iSocketClient,struct sendMsg sMsg)
{
	printf("___________transfer Money ing__________\n\n");
	int iSendLen;
	int iRecvLen;
	
	printf("please enter payee's account: ");
	scanf("%d",&sMsg.account);
	printf("please enter the money: ");
	scanf("%d",&sMsg.money);
	
	iSendLen = send(iSocketClient, &sMsg, sizeof(sMsg), 0);
	if (iSendLen <= 0)
	{
		close(iSocketClient);
		return -1;
	}

	int balanceBuf;
	iRecvLen = recv(iSocketClient, &balanceBuf, sizeof(balanceBuf), 0);
	if (iRecvLen <= 0)
	{
		printf("___________transfer Money failed__________\n\n");
		close(iSocketClient);
		return -1;
	}
	else if(balanceBuf < 0)
	{
		printf("transfer failed!\n The account is wrong or your balance is not sufficient! \n\n" );
	}
	else
	{
		printf("transfer Succeed!\n Your balance is:  %d\n\n",balanceBuf );
	}
	
	return 0;
}


int CreatSocekt()
{
	int iSocketClient;
	iSocketClient = socket(AF_INET, SOCK_STREAM, 0);
	
	struct sockaddr_in tSocketServerAddr;	
	
	tSocketServerAddr.sin_family = AF_INET;
	tSocketServerAddr.sin_port   = htons(SERVER_PORT);
	tSocketServerAddr.sin_addr.s_addr = htonl(INADDR_ANY);   
 	if (0 == inet_aton("10.1.65.142", &tSocketServerAddr.sin_addr))
 	{
		printf("Server IP error!\n");
		return -1;
	}
	memset(tSocketServerAddr.sin_zero, 0, 8);
	
	int iRet;
	iRet = connect(iSocketClient, (const struct sockaddr *)&tSocketServerAddr, sizeof(struct sockaddr));	
	if (-1 == iRet)
	{
		printf("connect failed!!\n");
		return -1;
	}
	
	return iSocketClient;
}



int main()
{	
	int iSocketClient = CreatSocekt();
	if (-1 == iSocketClient)
	{
		printf("socket error!\n");
		return -1;
	}
	
		
	login(iSocketClient);
		
		
	close(iSocketClient);
	return 0;
}

注：linux系统中，因为使用了多线程函数，所以编译时加上 -lpthread

gcc server.c -o server -lpthread

gcc client.c -o client -lpthread