OOP Lecture 24-Network Programming-Part1.pptx
- 1. CS3135/CS2135 Object Oriented Programming (Java) BSCS-3 / MCS-3 Lecture # 24 Network Programming Part-1
- 2. Java Network Programming • Network Programming refers to writing programs that execute across multiple devices (computers), in which the devices are all connected to each other using a network. • IP address is a unique number assigned to a node of a network e.g. 192.168.0.1 . It is composed of octets that range from 0 to 255. It is a logical address that can be changed. • Protocol is a set of rules basically that is followed for communication. For example: • TCP, FTP, Telnet, SMTP, POP etc. • Port Number is used to uniquely identify different applications. It acts as a communication endpoint between applications. • The port number is associated with the IP address for communication between two applications. • In connection-oriented protocol, acknowledgement is sent by the receiver. So it is reliable but slow. The example of connection-oriented protocol is TCP. • In connection-less protocol, acknowledgement is not sent by the receiver. So it is not reliable but fast. The example of connection-less protocol is UDP. • Socket is an endpoint between two way communication. Instructor: Tanzila Kehkashan 2
- 3. Socket Programming • Java Socket programming can be of two types: • Connection-oriented uses classes Socket and ServerSocket • Connection-less.uses classes DatagramSocket and DatagramPacket • The client in socket programming must know two information. • IP Address of Server, and Port number. java.net.Socket • Socket class can be used to create a socket and to connect to a remote host. • Socket(String, int) //host, port • InputStream getInputStream() //returns the InputStream attached with current socket object. • OutputStream getOutputStream() //returns the OutputStream attached with curent socket object. • synchronized void close() //closes this socket Instructor: Tanzila Kehkashan 3
- 4. Socket Programming java.net.ServerSocket • The ServerSocket class can be used to create a server socket. This object is used to accept connections from client sockets. • ServerSocket(int) //port • Socket accept() //returns the socket and establish a connection between server and client. • synchronized void close() //closes the server socket. Instructor: Tanzila Kehkashan 4
- 5. • Run two instances of Command Prompt. • Run server file first. Instructor: Tanzila Kehkashan 5
- 6. • Both server and client communicates Instructor: Tanzila Kehkashan 6