Help! fail to connect in tcpip

[lilyaaa]

I am new to Symbian C++ and I try to write a tcpip client to send data.
I also use java to write the server and run on the same computer.

I find some code on the web write it inside one file and like that but the emulator close after runing a while,
it seems fail in lSocket.Connect(lServSockAddr,status) and my Java Server doesn't get any client.
Does anyone can tell me what's wrong? Thank you very much!

This is all my code:

#include <e32cons.h>
#include <es_sock.h>
#include <in_sock.h>

// Function prototype
LOCAL_C void UseBasicTypesL();

//////////////////////////////////////////////////////////////////////////////
//
// Main function called by E32
//
//////////////////////////////////////////////////////////////////////////////
GLDEF_C TInt E32Main()
{

// Catch any Leaves thrown
TRAPD(error, UseBasicTypesL());

_LIT(KMsgPanic,"Error in Symbian OS Basics Lab: ");
__ASSERT_ALWAYS(!error, User::Panic(KMsgPanic, error));

return 0;
}


//////////////////////////////////////////////////////////////////////////////

LOCAL_C void UseBasicTypesL()
{
// Constant text used for the console app title
_LIT(KLabTitle,"Testing");

CConsoleBase* console = Console::NewL(KLabTitle, TSize(KConsFullScreen, KConsFullScreen));

TRequestStatus status;
RSocketServ lSession;
RSocket lListenSocket, lSocket;

TInt lErr;

// Connect to the socket server
lErr=lSession.Connect();
User::LeaveIfError(lErr);

lErr = lListenSocket.Open(lSession,KAfInet, KSockStream,KProtocolInetTcp);
User::LeaveIfError(lErr);

TInetAddr lServSockAddr;

const TUint32 KInetAddr = INET_ADDR(127,0,0,1);

lServSockAddr.SetAddress(KInetAddr);

lServSockAddr.SetPort(5888);

lSocket.Connect(lServSockAddr,status); // it seems fail at here when I use debug mode

const TText8* txt = (TText8*)_S("My Tcpip client test");
TBuf8<100> sbuf(txt);
lSocket.Send(sbuf, 0, status));

TBuf8<100> rbuf;
TSockXfrLength aLen;
lSocket.RecvOneOrMore(rbuf,0,status, aLen);
console->Printf(_L("Received Data is:: "),rbuf);


// Continue
_LIT(KMsgPressAnyKey,"Press any key to end");
console->Printf(KMsgPressAnyKey);
console->Getch();

delete console;
}

[wizard_hu_]

Communication over sockets is an asynchronous activity. It means that Connect, Send, RecvOneOrMore calls return immediately, and they will notify you about the result in the TRequestStatus variable, later.
In such test code, you can put "User::WaitForRequest(status);" after each of these calls, then it will work.
Printing the received data will not succeed, because it is in a 8-bit descriptor, while Printf works with Unicode data.

TBuf<100> rbuf16;
rbuf16.Copy(rbuf);
console->Printf(_L("Received Data is:: %S"),&rbuf16);

does the conversion, and also print something.

[lilyaaa]

Thanks for your reply , I try the way you say to modify the code, but the problem still the same: it close immediately when it
goes to the connect part. I have read many documents and it seems it is a very simple code, I don't know why it has problem.
My java server program is listen to port 1234 and it can accept other java tcp client in my computer but except this.
Please Help Me.

CConsoleBase* console = Console::NewL(KLabTitle, TSize(KConsFullScreen, KConsFullScreen));
TRequestStatus status;
RSocketServ lSession;
RSocket lListenSocket, lSocket;

TInt lErr;

// Connect to the socket server
lErr=lSession.Connect();
User::LeaveIfError(lErr);

lErr = lListenSocket.Open(lSession,KAfInet, KSockStream,KProtocolInetTcp);
User::LeaveIfError(lErr);

TInetAddr lServSockAddr;

const TUint32 KInetAddr = INET_ADDR(192,168,10,211);
lServSockAddr.SetAddress(KInetAddr);
lServSockAddr.SetPort(1234);

lSocket.Connect(lServSockAddr,status); // it close suddenly here
User::WaitForRequest(status);

const TText8* txt = (TText8*)_S("TCP Client Testing!");
TBuf8<100> sbuf(txt);
lSocket.Send(sbuf, 0, status);
User::WaitForRequest(status);

TBuf8<100> rbuf;
TSockXfrLength aLen;
lSocket.RecvOneOrMore(rbuf,0,status, aLen);
User::WaitForRequest(status);

TBuf<100> rbuf16;
rbuf16.Copy(rbuf);
console->Printf(_L("Received Data is:: %S"),&rbuf16);
..........

[symbianyucca]

Check the panic code: http://wiki.forum.nokia.com/index.ph...ded_panic_code

Also it would be a lot better to actually use active objects and not WaitForRequest.

[wizard_hu_]

TRequestStatus stores result code of asynchronous activities.
Whenever you wait for a given request, you could print its result after it has completed:

User::WaitForRequest(status);
console->Printf(_L("stat: %d"),status.Int());
console->Getch();

0 is KErrNone - everything is fine
-x is some error: http://wiki.forum.nokia.com/index.php/Error_codes
The Getch is there for enabling you to read the code prior to the crash :-)

Jukka: I think it is acceptable if beginners experiment with console-based "linear" code - I also do that rather often

[symbianyucca]

Jukka: I think it is acceptable if beginners experiment with console-based "linear" code - I also do that rather often

Certainly it is ok for experiment, anyway, some people think that they can actually do that in release code and still have application that behaves and responds well, so just trying to get people to use something that actually work in the long run..

[lilyaaa]

THank you for you reply. But the problem is still there. and I find out that my code hangs with KERN-EXEC 0 :trying to use a not created object in the line

lSocket.Connect(lServSockAddr,status);

Even I want to print out the status.

lSocket.Connect(lServSockAddr,status);
User::WaitForRequest(status);
console->Printf(_L("stat: %d"),status.Int());
console->Getch();

Since it quit immediately, I cannot see any status and I think it doesnot execute User::WaitForRequest(status) and after codes.
I found a post http://discussion.forum.nokia.com/fo...d.php?t=171997 and add CAPABILITY localservices but no use.

and the lErr are 0 in:

lErr=lSession.Connect();
User::LeaveIfError(lErr);

lErr = lListenSocket.Open(lSession,KAfInet, KSockStream,KProtocolInetTcp);
User::LeaveIfError(lErr);

SO I really don't know the problem is.

[wizard_hu_]

lSocket.Connect(lServSockAddr,status);

...

lErr = lListenSocket.Open(lSession,KAfInet, KSockStream,KProtocolInetTcp);
User::LeaveIfError(lErr);

SO I really don't know the problem is.

Well, I do: you have two sockets for some reason, initialize one of them, then attempting to use the other, that is why.
The client needs one socket only, thus you could avoid such issues via simply commenting the declaration of lListenSocket for now.

[lilyaaa]

Well, I do: you have two sockets for some reason, initialize one of them, then attempting to use the other, that is why.
The client needs one socket only, thus you could avoid such issues via simply commenting the declaration of lListenSocket for now.

Yes! You are right!!!!!! My server can recieve the connection now!!!!! Thank you very much!!!!!!!!

[lilyaaa]

Now my server can get the connection and my client can receive the data from server , but cannot reverse.

my Send is like this and the status is 0 and it seems send successfully:

const TText8* txt = (TText8*)_S("TCP Client Testing!");
TBuf8<100> sbuf(txt);
lSocket.Send(sbuf, 0, status);

and in my java code, I use

BufferedReader br = new BufferedReader(new InputStreamReader(clientSocket.getInputStream()));
String message = br.readLine(); // waits for input now
System.out.println("The message is " + message);

but its seem no message can be read and wait at the line with readline.
Does anybody know how to read the data from symbian c++ in java?

[wizard_hu_]

Note that _S creates a 16-bit (Unicode) string of your text, which means that its second byte of your message is going to be 0. It may or may not affect BufferedReader - but as far as I remember it expects normal ASCII stream by default.
What happens if you send _LIT8(KMessage,"TCP Client Testing!") or even an in-place _L8("TCP Client Testing!")?

[lilyaaa]

Note that _S creates a 16-bit (Unicode) string of your text, which means that its second byte of your message is going to be 0. It may or may not affect BufferedReader - but as far as I remember it expects normal ASCII stream by default.
What happens if you send _LIT8(KMessage,"TCP Client Testing!") or even an in-place _L8("TCP Client Testing!")?

THanks for you reply, I try

_LIT8(KMessage,"TCP Client Testing!");
lSocket.Send(KMessage, 0, status);
and

lSocket.Send(_L8("TCP Client Testing!"), 0, status);
and

lSocket.Write(_L8("I am Client "),status);
and
_LIT8(KMessage,"TCP Client Testing!");
lSocket.Write(KMessage,status);

status return is 0 but still cannot be received in java Server. Server keep waiting for reading.

[wizard_hu_]

Note that you do not send a line break, which probably cause readLine to wait until the socket gets closed.
You can also try if direct usage of InputStream makes a difference, in this case assumptions of Reader/BufferedReader would not matter since you get the raw bytes.

[lilyaaa]

Note that you do not send a line break, which probably cause readLine to wait until the socket gets closed.
You can also try if direct usage of InputStream makes a difference, in this case assumptions of Reader/BufferedReader would not matter since you get the raw bytes.

Yes, you are right! I add \n at the end of message and it's work.
Thank you very much!