Vector trouble 1

[ankursaxena]

Hi, I have a Vector of sockets, every so often I send packets to all the sockets in the vector using the following code. Before sending I check if the socket is connected, if it is cont sending, else close the socket, input/output streams and remove it from the vector, but it doesnt seem to work. Here you go...

		AppConstants.traceln("Sockets to send to: " + status_manager.rt_comm.outStreams.size());
		ListIterator iter = status_manager.rt_comm.outStreams.listIterator();
		ListIterator iter_sock = status_manager.rt_comm.clientSockets.listIterator();
		ListIterator iter_in = status_manager.rt_comm.inStreams.listIterator();

		int o_count = 0;
		while (iter.hasNext())
		  {
		    try
		      {
			Socket sock = (Socket)iter_sock.next();
			ObjectOutputStream oos = (ObjectOutputStream)iter.next();
			ObjectInputStream ois = (ObjectInputStream)iter_in.next();

			if(sock.isConnected())
			  {
			    oos.writeObject((id == 0? "PTxAS_1" : "PTxAS_2"));
			    oos.writeObject(ids);
			    oos.writeObject(vals);
			    oos.flush();
			    AppConstants.traceln("Writting to " + o_count + " socket");
			  }
			else
			  {
			    //remove sock and steam
			    oos.close();
			    ois.close();
			    sock.close();
			    status_manager.rt_comm.inStreams.remove(ois);
			    status_manager.rt_comm.outStreams.remove(oos);
			    status_manager.rt_comm.clientSockets.remove(sock);
			    AppConstants.traceln("Removed socket/IO-Streams from vectors because conn was closed by client");
			  }
			
			o_count++;
		      }
		    catch(Exception exc)
		      {
			AppConstants.traceln("Exception occured while sending to socket " + o_count);
			exc.printStackTrace(AppConstants.log_file);
		      }

Is it that when I get the object from the vector it really is a copy and when I close that, it doesnt close the actual connection?

I keep getting this error..

3213: Sockets to send to: 3
3214: Exception occured while sending to socket 0
java.net.SocketException: Broken pipe
at java.net.SocketOutputStream.socketWrite0(Native Method)
at java.net.SocketOutputStream.socketWrite(Unknown Source)
at java.net.SocketOutputStream.write(Unknown Source)
at java.ibjectOutputStream$BlockDataOutputStream.drain(Unknown Source)
at java.ibjectOutputStream$BlockDataOutputStream.writeByte(Unknown Source)
at java.ibjectOutputStream.writeFatalException(Unknown Source)
at java.ibjectOutputStream.writeObject(Unknown Source)
at PTXConnThread.run(PTXStatus.java:292)
at java.lang.Thread.run(Unknown Source)
3215: Exception occured while sending to socket 0
java.net.SocketException: Broken pipe
at java.net.SocketOutputStream.socketWrite0(Native Method)
at java.net.SocketOutputStream.socketWrite(Unknown Source)
at java.net.SocketOutputStream.write(Unknown Source)
at java.ibjectOutputStream$BlockDataOutputStream.drain(Unknown Source)
at java.ibjectOutputStream$BlockDataOutputStream.writeByte(Unknown Source)
at java.ibjectOutputStream.writeFatalException(Unknown Source)
at java.ibjectOutputStream.writeObject(Unknown Source)
at PTXConnThread.run(PTXStatus.java:292)
at java.lang.Thread.run(Unknown Source)
3216: Exception occured while sending to socket 0

I had the code in place, where in the excpetion I would close everything, but that didnt affect, so I removed it and really the time when the exception is thrown the connection.isconnected() should return a false, next time and automatically remove it.

Dont know whats happening here, thanks

Thanks for any help.

Ankur

 

[ankursaxena]

Whats the difference between remove and removeELemet??

they seem to be one and the same

 

[sedj]

I admittedly have not read your entire [long] post, but one thing struck me from the first line. Why, oh why, are you storing socket objects in a vector ? This is just asking for a nightmare. I have no doubt you have a broken pipe.

When working with sockets, IMO, the golden rule is :
open socket, send/recv data, close socket.

Simple as that. Do NOT keep sockets open unecesssarily. This is just bad programming technique.

--------------------------------------------------
Free Database Connection Pooling Software

http://www.primrose.org.uk

 

[ankursaxena]

See I have not seen much that you open a socket and close it after sending and recving information. Here I have to keep the connection alive because I have to non-stop send or recv information, it has to be open all the time, I dont know when I will recv data and I dont know when I will have to send data.

plus I dont know how many client will be connecting to me, so what do I do, I cant close the connection plus I dont know how many will connect, so where else will I store the connections?

But thanks for looking into it.

Ankur

 

[sedj]

If you are recieving data, you should use a ServerSocket object, and so listen constantly on a port.

If you are sending data, you should open a Socket object, send the data, read any response, and then close it.

--------------------------------------------------
Free Database Connection Pooling Software

http://www.primrose.org.uk

 

[timw]

I'd have a read up on client/server coding using sockets at

http://java.sun.com/docs/books/tutorial/networking/sockets/

Tim

 

[Diancecht]

I think this has nothign to do with a Vector problem but anyway:

- remove and removeElement methods have the same functionality. The remove one is just there to implement the List interface.

- Vector and ArrayList offer the same functionality, but ArrayList is not synchronized. So if you're not accesing concurrently, you should use ArrayList.

Anyway, instead of a Vector I think you need a pool here.

Cheers,

Dian

 

[ascotta]

Giving timw a star becuase I had fallen by the wayside in teaching myself Java, by following his link it has re-ignited my ambition to do some more stuff.


[blue]Arguably the best cat skinner around ! [/blue]

Cheers
Scott