Question

In Java, I need to know what is the bind operation:

ServerSocket.bind()

From Javadoc:

Binds the ServerSocket to a specific address (IP address and port
number).

I know what is bind and EJB (from example) to a name. Is this similar?

How to bind a local address to a server socket?

I am using:

providerSocket.bind(new InetSocketAddress("192.168.0.1", 0));

And I got Already Bound error!

Answer 1

A connection requires a client and a server.

For a client to send data to the server, the client must have the server’s address and port number. Similarly, for the server to send data to the client, the server must have the client’s address and port number.

Binding a socket means assigning an address and port number to the socket.

When you do:

providerSocket.bind(new InetSocketAddress("192.168.0.1", 0));

You get Already Bound error because providerSocket already has an address and port number, and assigning a new address / port number is not allowed. Once a ServerSocket is created, it is bound (unless it uses the parameterless constructor java.net.ServerSocket.ServerSocket()).