I started to program client/server applications in J2ME recently.Now I'm working with c++ builder 2010 indy components (e.g. TidTTCPServer) and J2ME. My application is designed to restart the kerio winroute firewall service from a remote machine.
My server application is written in c++ builder 2010, I've put a TidTCTServer component into a form which binded to 127.0.0.1:4500. That's listening on port 4500 in local machine.
Then i've added a listbox that i need to add every upcoming packets converted to UnicodeString.
//void __fastcall TForm1::servExecute(TIdContext *AContext)
UnicodeString s;
UnicodeString txt;
txt=Trim(AContext->Connection->IOHandler->ReadLn());
otvet->Items->Add(txt);
otvet->ItemIndex=otvet->Items->Count-1;
if (txt=="1") {
AContext->Connection->IOHandler->WriteLn("Suhrob");
AContext->Connection->Disconnect();
}
if (txt=="2") {
AContext->Connection->IOHandler->WriteLn("Shodi");
AContext->Connection->Disconnect();
}
//----------------------------------------------------------------------------
// void __fastcall TForm1::servConnect(TIdContext *AContext)
++counter;
status->Panels->Items[0]->Text="Connections:" + IntToStr(counter);
status->Panels->Items[1]->Text="Connected to " + AContext->Connection->Socket->Binding->PeerIP + ":" + AContext->Connection->Socket->Binding->PeerPort;
and my client side code looks smth like this:
else if (command == send) {
// write pre-action user code here
InputStream is=null;
OutputStream os=null;
SocketConnection client=null;
ServerSocketConnection server=null;
try {
server = (ServerSocketConnection) Connector.open("socket://"+IP.getString()+":"+PORT.getString());
// wait for a connection
client = (SocketConnection) Connector.open("socket://"+IP.getString()+":"+PORT.getString());
// set application-specific options on the socket. Call setSocketOption to set other options
client.setSocketOption(SocketConnection.DELAY, 0);
client.setSocketOption(SocketConnection.KEEPALIVE, 0);
is = client.openInputStream();
os = client.openOutputStream();
// send something to server
os.write("texttosend".getBytes());
// read server response
int c = 0;
while((c = is.read()) != -1) {
// do something with the response
System.out.println((char)c);
}
// close streams and connection
}
catch( ConnectionNotFoundException error )
{
Alert alert = new Alert(
"Error", "Not responding!", null, null);
alert.setTimeout(Alert.FOREVER);
alert.setType(AlertType.ERROR);
switchDisplayable(alert, list);
}
catch (IOException e)
{
Alert alert = new Alert("ERror", e.toString(), null, null);
alert.setTimeout(Alert.FOREVER);
alert.setType(AlertType.ERROR);
switchDisplayable(alert, list);
e.printStackTrace();
}
finally {
if (is != null) {
try {
is.close();
} catch (Exception ex) {
System.out.println("Failed to close is!");
}
try {
os.close();
} catch (Exception ex) {
System.out.println("Failed to close os!");
}
}
if (server != null) {
try {
server.close();
} catch (Exception ex) {
System.out.println("Failed to close server!");
}
}
if (client != null) {
try {
client.close();
} catch (Exception ex) {
System.out.println("Failed to close client!");
}
}
}
my client application gets connected with the server but when i try to send data such as
os.write("texttosend".getBytes());
I cannot get text data on the server using. That's I am not getting sent packets in the server from client.
txt=Trim(AContext->Connection->IOHandler->ReadLn());
Guys, where am I wrong? is the way i'm doing is ok?
Or do I need to use StreamConnection instead of SocketConnection?
And when i use telnet to send data it works cool, strings will be added to listbox
telnet 127.0.0.1 4500
texttosend
23
asf
Any help is appreciated !!!
Thanks in advance!
The main problem is that you are using ReadLn() on the server end. ReadLn() does not exit until a data terminator is encountered (a LF line break character is the default terminator) or if a reading timeout occurs (Indy uses infinite timeouts by default). Your J2ME code is not sending any data terminator, so there is nothing to tell ReadLn() when to stop reading. The reason it works with Telnet is because it does send line break characters.
The other problem with your code is that TIdTCPServer is a multi-threaded component, but your code is updating the UI components in a thread-unsafe manner. You MUST synchronize with the main thread, such as by using Indy's TIdSync and/or TIdNotify classes, in order to update your UI safely from inside of the server's event handlers.
Yes, flush method is necessary to call after sending bytes, but ..... finally....
then i tried to include my connection code in a new thread that implements Runnable worked perfectly. Now I've found where I was wrong!!!!!!!!!!!!!!
That's guys you need to include above code in the following block.
Thread t= new Thread(this);
t.start();
public void run()
{
//here paste the code
}
Try OutputStream.flush()?
If not, try writing to a known working server, instead of one you've created yourself (something like writing "HELO" to an SMTP server), this will help you figure out which end the error is at.
Related
I have a server method that waits for new incoming TCP connections, for each connection I'm creating two threads (detached) for handling various tasks.
void MyClass::startServer(boost::asio::io_service& io_service, unsigned short port) {
tcp::acceptor TCPAcceptor(io_service, tcp::endpoint(tcp::v4(), port));
bool UARTToWiFiGatewayStarted = false;
for (;;) {
auto socket(std::shared_ptr<tcp::socket>(new tcp::socket(io_service)));
/*!
* Accept a new connected WiFi client.
*/
TCPAcceptor.accept(*socket);
socket->set_option( tcp::no_delay( true ) );
MyClass::enableCommunicationSession();
// start one worker thread.
std::thread(WiFiToUARTWorkerSession, socket, this->LINport, this->LINbaud).detach();
// only if this is the first connected client:
if(false == UARTToWiFiGatewayStarted) {
std::thread(UARTToWifiWorkerSession, socket, this->UARTport, this->UARTbaud).detach();
UARTToWiFiGatewayStarted = true;
}
}
}
This works fine for starting the communication, but the problem appears when the client disconnects and connects again (or at least tries to connect again).
When the current client disconnects, I stop the communication (by stopping the internal infinite loops from both functions, then they'll return).
void Gateway::WiFiToUARTWorkerSession(std::shared_ptr<tcp::socket> socket, ...) {
/*!
* various code here...
*/
try {
while(true == MyClass::communicationSessionStatus) {
/*!
* Buffer used for storing the UART-incoming data.
*/
unsigned char WiFiDataBuffer[max_incoming_wifi_data_length];
boost::system::error_code error;
/*!
* Read the WiFi-available data.
*/
size_t length = socket->read_some(boost::asio::buffer(WiFiDataBuffer), error);
/*!
* Handle possible read errors.
*/
if (error == boost::asio::error::eof) {
break; // Connection closed cleanly by peer.
}
else if (error) {
// this will cause the infinite loops from the both worker functions to stop, and when they stop the functions will return.
MyClass::disableCommunicationSession();
sleep(1);
throw boost::system::system_error(error); // Some other error.
}
uart->write(WiFiDataBuffer, length);
}
}
catch (std::exception &exception) {
std::cerr << "[APP::exception] Exception in thread: " << exception.what() << std::endl;
}
}
I expect that when I reconnect the communication should work again (the MyClass::startServer(...) will create and detach again two worker threads that will do the same things.
The problem is that when I connect the second time I get:
terminate called after throwing an instance of 'boost::exception_detail::clone_impl<boost::exception_detail::error_info_injector<boost::system::system_error> >'
what(): write: Broken pipe
From what I found about this error it seems that the server (this application) sends something via TCP to a client that was disconnected.
What I'm doing wrong?
How can I solve this problem?
A read of length 0 with no error is also an indication of eof. The boost::asio::error::eof error code is normally more useful when you're checking the result of a composed operation.
When this error condition is missed, the code as presented will call write on a socket which has now been shutdown. You have used the form of write which does not take a reference to an error_code. This form will throw if there is an error. There will be an error. The read has failed.
I am working on LM4F232H5QD board and want to read com port data. Whenever i use Tera term or any other serial terminal i got data from com port.
But when i use this code i got Timeout Exception error.
// _serialPort
//
this->_serialPort->PortName = L"COM3";
this->_serialPort->ReadTimeout = 5000;
this->_serialPort->WriteTimeout = 5000;
.
.
.
.
// Read button --------------------------------------
//this will start the asyn for backgroundwork
private: System::Void button3_Click(System::Object^ sender, System::EventArgs^ e) {
// check if port is ready for reading
if(this->_serialPort->IsOpen){
// Reset the text in the result label.
this->textBox2->Text = String::Empty;
// this will read manually
try{
this->textBox2->Text=this->_serialPort->ReadLine();
// printf("trying to read data");
}
catch(TimeoutException^){
this->textBox2->Text="Timeout Exception";
}
// Disable the init button
// the asynchronous operation is done.
this->button2->Enabled = false;
this->ovalShape1->FillColor= Color::Green;
}
else
// give error warning
this->textBox2->Text="Port Not Opened";
}
But when i short Rx and Tx pins it works good.
Can anyone please tell me how can i solve this problem?
If you are sure the data looks good from a terminal, shorting the pins won't help. The only read function you use is ReadLine(), which will wait until it receive a NewLine. Are you sure you are sending a NewLine correctly ? Also, you should check the actual value of _serialPort->NewLine, maybe it is set to CRLF and you are only receiving a LF.
I have a NodeJS / SocketIO app which connects to my Minecraft server through RCON protocol and it works perfectly, keep the connection open and listens for any kind of data which is retrieved.
Example, if I type a command which isn't available, it will respond with a message.
Now I'm trying to whenever any player on the Minecraft server chats, my Bukkit plugin will take that message and send it through to any connected on RCON.
This is part of my Bukkit plugin which fires when the player chats.
#EventHandler
public void onPlayerChat( AsyncPlayerChatEvent e ) {
Bukkit.getLogger().info("Test 1");
this.getLogger().info("Test 2");
Bukkit.getServer().getConsoleSender().sendMessage("Test 3");
this.getServer().getConsoleSender().sendMessage("Test 4");
}
The messages are recorded in the server log, though I do not get anything back through the rcon protocol.
RCON used by minecraft does not have a mechanism to send messages back after the initial packets. If you need a mechanism like this, you need to invent your own protocol, or make a command that returns the last chat log if it's executed.
To make this command, we can simple make a Queue<String> where we are putting our messages (like chat) into.
final Queue<String> messages = new ArrayDeque<>(64);
public void insertMessage(String message) {
synchronized (messages) {
messages.add(message);
if (messages.size() == 64) // full
messages.remove();
}
}
We can then hook up this method to our chat event:
#EventHandler(priority=EventPriority.MONITOR,ignoreCancelled=true)
public void onChat(AsyncPlayerChatEvent evt) {
insertMessage("[CHAT] " + evt.getPlayer() + " : " + evt.getMessage());
}
Then we only need to make a command to read out our messages list, this is easy to make:
private String getMessage() {
synchronized (messages) {
return messages.poll();
}
}
#Override
public boolean onCommand(CommandSender sender, Command cmd, String label, String[] args) {
if(!cmd.testPermissions()) {
return true;
}
String message;
while((message = getMessage()) != null) {
sender.sendMessage(message);
}
}
This allows you to get the server log from rcon by just typing in a command or making your client application so that it executes this command every second or so.
Im building a TCP client using Boost::asio Libs. My program has a write() thread that sends a command to the server
write(*_socket,boost::asio::buffer("sspi l1\n\n",sizeof("sspi l1\n\n")));
Then a read thread is started that reads from the buffer all the time, as there can be messages broadcasted from the server due to any other client
void TCP_IP_Connection::readTCP()
{
size_t l=0;
this->len=0;
boost::system::error_code error;
try
{//loop reading all values from router
while(1)
{
//wait for reply??
l=_socket->read_some(boost::asio::buffer(this->reply,sizeof(this->reply)),error);
if(error)
throw boost::system::system_error(error);
if(l>0)
{
this->dataProcess(l);
}
else
boost::this_thread::sleep(boost::posix_time::milliseconds(5000));
_io.run();
if(error==boost::asio::error::eof) //connection closed by router
std::cout<<"connection closed by router";
_io.reset();
}
}
catch (std::exception& e)
{
std::cerr << e.what() << std::endl;
}
}
This thread runs al time in a while(1) loop and is supposed to sleep when the received data length is less than zero. It reads all the data and calls the data parser function. After that the write thread is used to send another command, with read thread running. But instead of the required response the server sends back
? ""
ERROR: Unknown command
I tried using the wireshark. I can see the command being send properly. What can be mistake I'm doing here?
sizeof("sspi l1\n\n") returns 10, but I can only count 9 characters in that string.
Try this instead:
const std::string cmd("sspi l1\n\n");
write(*_socket,boost::asio::buffer(cmd, cmd.length()));
Or when you have it as a string it is enough to do
const std::string cmd("sspi l1\n\n");
write(*_socket,boost::asio::buffer(cmd));
The second argument specifies a maximum length of the string to use. But since it is a constant string, the second argument is not strictly necessary.
I have an java app for blackberry, created with Java Plug-in for Eclipse. I want to invoke a webservice on a webserver through Blackberry mds. The code I am using works, but is not stabile. Meaning that I get successfully get in contact with web server 100 times in a row, but after a while, the connection is broken. The log files from Blackberry are many and not easy to read, but at least I a feel that the phrase "Invalid socket" is not good for me.
I am using StreamConnection class in my code, but I see from some sample code that httpConnection is used instead. Anyone know when to use HttpConnection instead of StreamConnection?
I paste my code here. Perhaps some of you see anything I should have done different:
private boolean sendStatusMessage(String phoneNumber, String status) {
StreamConnection conn = null;
OutputStream output = null; //mari added
try {
String body = "<soapenv:Envelope xmlns:soapenv=\"http://schemas.xmlsoap.org/soap/envelope/\" xmlns:i3w=\"http://I3WebAction\">"
+ "<soapenv:Header/>"
+ "<soapenv:Body>"
+ "<i3w:I3SetMobileStatus><i3w:p_Status>"
+ status
+ "</i3w:p_Status><i3w:p_PhoneNumber>"
+ phoneNumber
+ "</i3w:p_PhoneNumber>"
+ "</i3w:I3SetMobileStatus></soapenv:Body></soapenv:Envelope>";
String URL = "socket://" + soapServer + ":" + port
+ ";deviceside=false";
conn = (StreamConnection) Connector.open(URL);
//OutputStream output = conn.openOutputStream();
output = conn.openOutputStream();
OutputStreamWriter writer = new OutputStreamWriter(output);
writer.write("POST /SOAPListener/I3SOAPISAPIU.dll HTTP/1.1\r\n");
writer.write("Accept-Encoding: gzip,deflate\r\n");
writer.write("Content-Type: text/xml;charset=UTF-8\r\n");
writer.write("SOAPAction: \"http://I3WebAction/I3SetMobileStatus\"\r\n");
writer.write("User-Agent: Jakarta Commons-HttpClient/3.1\r\n");
writer.write("Host: lvkdb01\r\n");
writer.write("Content-Length: " + body.length() + "\r\n");
writer.write("\r\n");
writer.write(body);
writer.flush();
writer.close(); //mari added
} catch (Exception e) {
Dialog.alert(e.getMessage());
return false;
} finally {
try {
// Close stream regardless of exceptions and return-points
output.close();
} catch (IOException e) {
// If closing the stream causes exception, the stream is most
// likely not open or available. We display an error message,
// and continues the program.
Dialog.alert(e.getMessage());
return false;
}
try {
// Close stream regardless of exceptions and return-points
conn.close();
} catch (IOException e) {
// If closing the stream causes exception, the stream is most
// likely not open or available. We display an error message,
// and continues the program.
Dialog.alert(e.getMessage());
return false;
}
}
return true;
}
I appreciate any comments or ideas on why this code is not running stabile.
By default all requests through BES are transcoded. Try to turn off transcoding and see if that resolves your issue. To turn off transcoding you would need to pass the below header.
Turn off MD transcoding: ("x-rim-transcode-content", "none) as a header
MDS logs would be useful(default location c:\Program Files\Research In Motion\BlackBerryEnterprise Server\Logs)/
They end with “MDAT”. The logging level can be changed by following these instructions.
http://docs.blackberry.com/en/admin/deliverables/14334/Change_logging_level_for_MDSCS_552126_11.jsp
You may also way to enable Verbose HTTP logging for testing, found here, which can help trace through the http messages.
http://docs.blackberry.com/en/admin/deliverables/14334/Change_activities_MDSCS_writes_to_log_827932_11.jsp