Java in a Nutshell, 5th Edition

Name

Socket

Synopsis

This class implements a socket for stream-based communication over the network. See URL for a higher-level interface to networking and DatagramSocket for a lower-level interface.

Before you can use a socket for communication, it must be bound to a local address and connected to a remote address. Binding and connection are done automatically for you when you call any of the Socket( ) constructors except the no-argument constructor. These constructors allow you to specify either the name or the InetAddress of the computer to connect to, and also require you to specify the port number to connect to. Two of these constructors also allow you to specify the local InetAddress and port number to bind the socket to. Most applications do not need to specify a local address, and can simply use one of the two-argument versions of Socket( ) and can allow the constructor to choose an ephemeral local port to bind the socket to.

The no-argument Socket( ) constructor is different from the others: it creates an unbound and unconnected socket. In Java 1.4 and later, you can explicitly call bind( ) and connect( ) to bind and connect the socket. It can be useful to do this when you want to set a socket option (described below) that must be set before binding or connection. bind( ) uses a SocketAddress object to describe the local address to bind to, and connect( ) uses a SocketAddress to specify the remote address to connect to. There is also a version of connect( ) that takes a ...