Multiple input streams

Question

hey folks newbie here
i am designing a client server program
with my client i want to send serialized objects & primitive types across the socket to the server
is it possible to creat two output streams on the same socket i.e an ObjectOutputStream & a DataOutputStream on the same socket, i have tried this but get some errors so i don't think this is possible
if not possible how would i be able to send both primitive types & serialized objects across the same socket

Answer 1

Forget about the first person's post. He his correct, but it is not the solution used by most developers.
Multiple Input Streams/Output Streams are easy to create. A better "management" deal would be like FTP - FTP uses two port, one for data and one for commands.
Socket objectSocket = new Socket("www.object-server.com", objectPort);
Socket dataSocket = new Socket("www.data-server.com", dataPort);
The server should implement a class which represents the connection of both sockets as a single client. Somethig like this:
public class Connection {
    Socket dataSocket;
    Socket objectSocket;
    public Connection(Socket s1) {
        dataSocket = s1;
    public void addObjectSocket(Socket s2) {
        objectSocket = s2;
}You can then use this class (permission given to copy and use without license hereby granted) to manage the task.
There are also many other ways of doing this. You can also apply multiple i/o streams to the same socket - but your server/client needs to know which data type is being sent or to which stream the data needs to be read from.
Example: Client sends binary file to server (such as FTP)
ObjectOutputStream out = new ObjectOutputStream(socket.getOutputStream());
PrintWriter out2 = new PrintWriter(socket.getOutputStream());
The code above will work, but data send in one stream will not show up in the other stream. The server does the reverse for the input > adding different InputStreams to the socket, but when data is sent from the client's object stream both of the server's streams (BufferedReader or other text-based input) and the object stream will receieve the file, so you need to communicate between the client and server which stream to read from/write to.
Client: Send file via socket to server by means of ObjectOutputStream
Note: You should not need to implement the try-catch logic when passing the argument of the socket - since it would throw that in the class which was calling the constructor, but you CAN implement it here as long as it is not handled in the calling class. If you do, the complier should throw an error saying that the exception would not be thrown at this point.