Definition: Network Programming
Computer network programming involves writing computer programs that Allow processes to communicate with each other across a computer network.
Below is the lists of Some Java.NET Package Classes
| Java.NET Package | |
| Classes Description | |
| InetAddress | This class represents an Internet Protocol (IP) address. |
| URL | Class URL represents a Uniform Resource Locator, a pointer to a “resource” on the World Wide Web. |
| URLConnection | The abstract class URLConnection is the superclass of all classes that represent a communications link between the application and a URL. |
| ServerSocket | This class implements server sockets. |
| Socket | This class implements client sockets (also called just “sockets”). |
| DatagramPacket | This class represents a datagram packet. |
| DatagramSocket | This class represents a socket for sending and receiving datagram packets. |
Socket Basics
A Socket is one end point of two way communication link between two programs running on the network
A Socket is combination of an IP Address and a Port Number
Client – Server Communication
- Two Machines must Connect
- Server waits for Connection
- Client initiates Connection
- Server respond to the client request
Socket Overview
The server is just like any ordinary program running on a computer
Each Computer is equipped with some ports.
The server connects to one of the ports
This process is called Binding to a port
The Connection is called a server Socket
The Java server code that does this is as given below
Here 2412 is the port number
Server waits for the client machine to connect
Client possibly running on different machine
Client then connect to the connects to the port of the server’s computer
Connection is called a Client Socket
Clients already know the port 80
Now we can say connection is established between the client and server, Every time a client is found, its socket is extracted, and loop again waits for the next client.