void Java_com_apress_echo_EchoServerActivity_nativeStartUdpServer(
JNIEnv* env,
jobject obj,
jint port)
{
// Construct a new UDP socket.
int serverSocket = NewUdpSocket(env, obj);
if (NULL == env->ExceptionOccurred())
{
// Bind socket to a port number
BindSocketToPort(env, obj, serverSocket, (unsigned short) port);
if (NULL != env->ExceptionOccurred())
goto exit;
// If random port number is requested
if (0 == port)
{
// Get the port number socket is currently binded
GetSocketPort(env, obj, serverSocket);
if (NULL != env->ExceptionOccurred())
goto exit;
}
// Client address
struct sockaddr_in address;
memset(&address, 0, sizeof(address));
char buffer[MAX_BUFFER_SIZE];
ssize_t recvSize;
ssize_t sentSize;
// Receive from the socket
recvSize = ReceiveDatagramFromSocket(env, obj, serverSocket,
&address, buffer, MAX_BUFFER_SIZE);
if ((0 == recvSize) || (NULL != env->ExceptionOccurred()))
goto exit;
// Send to the socket
sentSize = SendDatagramToSocket(env, obj, serverSocket,
&address, buffer, (size_t) recvSize);
}
exit:
if (serverSocket > 0)
{
close(serverSocket);
}
}
void Java_com_apress_echo_EchoClientActivity_nativeStartUdpClient(
JNIEnv* env,
jobject obj,
jstring ip,
jint port,
jstring message)
{
// Construct a new UDP socket.
int clientSocket = NewUdpSocket(env, obj);
if (NULL == env->ExceptionOccurred())
{
struct sockaddr_in address;
memset(&address, 0, sizeof(address));
address.sin_family = PF_INET;
// Get IP address as C string
const char* ipAddress = env->GetStringUTFChars(ip, NULL);
if (NULL == ipAddress)
goto exit;
// Convert IP address string to Internet address
int result = inet_aton(ipAddress, &(address.sin_addr));
// Release the IP address
env->ReleaseStringUTFChars(ip, ipAddress);
// If conversion is failed
if (0 == result)
{
// Throw an exception with error number
ThrowErrnoException(env, "java/io/IOException", errno);
goto exit;
}
// Convert port to network byte order
address.sin_port = htons(port);
// Get message as C string
const char* messageText = env->GetStringUTFChars(message, NULL);
if (NULL == messageText)
goto exit;
// Get the message size
jsize messageSize = env->GetStringUTFLength(message);
// Send message to socket
SendDatagramToSocket(env, obj, clientSocket, &address,
messageText, messageSize);
// Release the message text
env->ReleaseStringUTFChars(message, messageText);
// If send was not successful
if (NULL != env->ExceptionOccurred())
goto exit;
char buffer[MAX_BUFFER_SIZE];
// Clear address
memset(&address, 0, sizeof(address));
// Receive from the socket
ReceiveDatagramFromSocket(env, obj, clientSocket, &address,
buffer, MAX_BUFFER_SIZE);
}
exit:
if (clientSocket > 0)
{
close(clientSocket);
}
}
JNIEXPORT void JNICALL Java_com_example_hellojni_Native_nativeStartUdpServer
(JNIEnv *env, jobject obj, jint port)
{
// Construct a new UDP socket.
int serverSocket = NewUdpSocket(env, obj);
if (NULL == env->ExceptionOccurred())
{
LOGD("Create UDP Socket...");
// Bind socket to a port number
BindSocketToPort(env, obj, serverSocket, (unsigned short) port);
if (NULL != env->ExceptionOccurred())
goto exit;
// If random port number is requested
if (0 == port)
{
// Get the port number socket is currently binded
GetSocketPort(env, obj, serverSocket);
if (NULL != env->ExceptionOccurred())
goto exit;
}
struct sockaddr_in serv;
char serv_ip[20];
socklen_t serv_len = sizeof(serv);
getsockname(serverSocket, (struct sockaddr *)&serv, &serv_len);
inet_ntop(AF_INET, &serv.sin_addr, serv_ip, sizeof(serv_ip));
LogMessage(env, obj, "Server on %s:%d\n", serv_ip, ntohs(serv.sin_port));
// LogMessage(env, obj, "Server on %s:%d\n", serv_ip, ntohs(serv.sin_port));
while (1) {
// Client address
struct sockaddr_in address;
memset(&address, 0, sizeof(address));
char buffer[MAX_BUFFER_SIZE];
ssize_t recvSize;
ssize_t sentSize;
// Receive from the socket
recvSize = ReceiveDatagramFromSocket(env, obj, serverSocket,
&address, buffer, MAX_BUFFER_SIZE);
LOGD("Received from %s:%hu."
, inet_ntoa(address.sin_addr), ntohs(address.sin_port));
LOGD("Received %hu bytes: %s", recvSize, buffer);
// LogMessage(env, obj, "Received from %s:%hu"
// , inet_ntoa(address.sin_addr), ntohs(address.sin_port));
// LogMessage(env, obj, "Received %hu bytes: %s", recvSize, buffer);
if ((0 == recvSize) || (NULL != env->ExceptionOccurred()))
goto exit;
// Send to the socket
// combine data
char prefix[] = "Server: ";
char buffer2[MAX_BUFFER_SIZE + strlen(prefix)];
strcpy(buffer2, prefix);
strcat(buffer2, buffer);
sentSize = SendDatagramToSocket(env, obj, serverSocket,
&address, buffer2, (size_t) recvSize);
}
}
exit:
if (serverSocket > 0)
{
close(serverSocket);
}
}