从PC TCP套接字将数据传输到Android设备（Android的NDK） [英] TCP socket Transfer data from PC to android device (Android NDK)
问题描述
我的工作来实现的Android设备（客户端）和PC（服务器）TCP套接字，用C实现了code ++（安卓NDK）。
I am working to implement TCP socket between Android device (client) and the PC (server), the code implemented by c++ (Android NDK).
每一件事情它的做工精细，当我运行在服务器端的输出服务器启动它等待连接到客户端。当我运行客户端的另一侧工作的时候，直到连接到服务器，我发现这个错误套接字连接到服务器错误
every thing it's work fine, when i do run to the server side the output "server starts" it waiting for connect to the client. and the other side when I do run for the client it work when until the connect to server and I find this error "socket connect to server error"
任何一个可以告诉我要的是什么问题？
can any one tell me want is the problem?
我想从服务器转移矩阵16 * 16的客户，形成客户机到服务器的想法......
the idea I want to transfer matrix 16*16 from server to client and form client to server...
服务器端：
MyServerThread::MyServerThread()
{
startServer();
}
void MyServerThread::run()
{
//std::cout<<"hi"<<std::endl;
for(int i=0;i<16;i++)
matrix[i]=(float)i;
memcpy(buf,matrix,4*16);
sendMSG();
}
//TCP socket
/* now create the server socket
make it an IPV4 socket (PF_INET) and stream socket (TCP)
and 0 to select default protocol type */
if ( (server_skt = socket(AF_INET, SOCK_STREAM, 0)) == -1 ){
std::cerr<<"socket creation failed"<<std::endl;
exit(1);
}
//Initail, bind to port
/* now fill in values of the server sockaddr_in struct
s_addr and sin_port are in Network Byte Order (Big Endian)
Since Intel CPUs use Host Byte Order (Little Endian), conversion
is necessary (e.g. htons(), and htonl() */
server_addr.sin_family = AF_INET;//IPv4
server_addr.sin_port = htons(PORT);
server_addr.sin_addr.s_addr = htonl(INADDR_ANY);
memset(server_addr.sin_zero, 0, 8);
//binding
/* now bind server port
associate socket (server) with IP address:port (server_addr) */
if ( bind(server_skt, (struct sockaddr*)&server_addr, sizeof(struct sockaddr)) == -1 ){
std::cerr<<"socket bind failed"<<std::endl;
exit(1);
}
int queueSize=1;
//Start listening, wait for connection from client with a pending queue of size
if ( listen(server_skt, queueSize) == -1 ){
std::cerr<<"socket listen failed"<<std::endl;
exit(1);
}
//Wait for connect!
bool gotClient=false;
while(!gotClient){
sin_size = sizeof(struct sockaddr_in);
socklen_t temp=sin_size;
std::cout<<"server starts"<<std::endl;
if ( (client_skt = accept(server_skt, (struct sockaddr*)&clients_addr, &temp)) == -1 ){
std::cerr<<"socket error"<<std::endl;}
else
{
gotClient=true;
std::cout<<"Got client"<<std::endl;
}
}
void MyServerThread::sendMSG()
{
if ( (numbytes = send(client_skt, buf, strlen(buf),0)) == -1){
std::cerr<<"server, normal send error"<<std::endl;
exit(1);
}
}
void MyServerThread::recvMSG()
{
if ( (numbytes = recv(client_skt, buf, bufferSize,0)) == -1 ){
std::cerr<<"server, normal recv error"<<std::endl;
exit(1);
}
}
客户端：
Client::Client()
{
}
void Client::startClient()
{
/* now fill in sockaddr_in for remote address */
serv_addr.sin_family = AF_INET;
/* save the server IP (input from Java */
serv_addr.sin_addr.s_addr = inet_addr(serverIP);
/* set port */
serv_addr.sin_port = htons(PORT);
memset(serv_addr.sin_zero, 0, 8);
/* create local stream socket */
client_skt = socket(PF_INET, SOCK_STREAM, 0);
if (client_skt < 0) {
__android_log_print(ANDROID_LOG_ERROR,"jni client","socket creation error");
exit(-1);
}
/* bind local socket to any port number */
local_addr.sin_family = AF_INET;
local_addr.sin_addr.s_addr = htonl(INADDR_ANY);
//local_addr.sin_addr.s_addr = inet_addr("127.0.0.1");
local_addr.sin_port = htons(PORT);
memset(local_addr.sin_zero, 0, 8);
rc = bind(client_skt, (struct sockaddr *) &local_addr, sizeof(local_addr));
if (rc < 0)
{
__android_log_print(ANDROID_LOG_ERROR,"jni client","socket bind error");
exit(1);
}
__android_log_print(ANDROID_LOG_INFO,"jni client","client start finished");
}
void Client::connectServer()
{
__android_log_print(ANDROID_LOG_INFO,"jni client","connect to server starts");
/* connect to server */
rc = connect(client_skt, (struct sockaddr *) &serv_addr, sizeof(serv_addr));
if (rc < 0)
{
__android_log_print(ANDROID_LOG_ERROR,"jni client","socket connect to server error");
exit(1);
}
__android_log_print(ANDROID_LOG_ERROR,"jni client","server connected");
}
void Client::sendMSG()
{
if ( (numbytes = send(client_skt, "hello!", strlen("hello!"),0) )== -1 ){
__android_log_print(ANDROID_LOG_ERROR,"jni client","send error");
//exit(1);
}
}
void Client::recvMSG()
{
if ( (numbytes = recv(client_skt, buf, bufferSize,0) ) == -1 ){
__android_log_print(ANDROID_LOG_ERROR,"jni client","recv error");
//exit(1);
}
else
{
memcpy (matrix, buf, numbytes);
for(int i=0;i<4;i++)
__android_log_print(ANDROID_LOG_INFO,"matrix","%f, %f, %f, %f",matrix[i*4],matrix[i*4+1],matrix[i*4+2],matrix[i*4+3]);
}
}
问候，
推荐答案
如果客户端和服务器在同一台机器上，你的连接（）可能会失败，EADDRINUSE（本地地址已在使用），因为你绑定的客户端和服务器相同的端口号：
If the client and server are on the same machine, your connect() might fail with EADDRINUSE (Local address is already in use) because you're binding both client and server to the same port number:
local_addr.sin_port = htons(PORT);
编辑客户机code，客户端绑定到端口0（即内核将选择一个未使用的临时端口为你），然后再试一次。
Edit the client code, binding the client to port 0 (which means the kernel will pick an unused ephemeral port for you), and try again.
即便这不是你有确切的问题，你应该总是记录了什么错误是由库函数返回。经过连接（）失败，登录字符串错误的值（错误）。
Even if this is not the exact problem you're having, you should always log what error was returned by library functions. After connect() fails, log the value of strerror(errno).
这篇关于从PC TCP套接字将数据传输到Android设备（Android的NDK）的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
