ppt of socket

17
Group Members Gurpreet Kaur(155) Himani Kakria Ritika Sharma Reetu Rani

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Page 1: Ppt of socket

Group MembersGurpreet Kaur(155)

Himani KakriaRitika Sharma

Reetu Rani

Page 2: Ppt of socket

Contents

O Socket ProgrammingO Server-Client CommunicationO .net PackageO The InetAddress Class & its methods

O getLocalHost()O getByName(String hostName)O getAllByName(String hostName)O getAddress() & getHostName()

O Socket ClassO ServerSocketClass

Page 3: Ppt of socket

Socket ProgrammingNetworking - process of making two or more computers communicate.

The important concept associated with networking is the concept of Sockets and Ports.

SOCKET - A socket is one end-point of a two-way communication link between two programs running on the network.

Socket classes are used to represent the connection between a client program and a server program.

Page 4: Ppt of socket

Server-Client Communication

O Normally, a server has a socket that is bound to a specific port number.

O On the client-side: The client knows the hostname of the machine on which the server is running and the port number on which the server is listening.

O To make a connection request, the client tries to connect with the server on the server's machine and port.

O If everything goes well, the server accepts the connection.

O On the client side, if the connection is accepted, a socket is successfully created and the client can use the socket to communicate with the server.

Page 5: Ppt of socket

.net PackageO Provide support for networking.

O Contains classes and interfaces to encapsulate the “Socket” Paradigm.

O The java.net package provides two classes—O Socket - implement the client side of the

connectionO ServerSocket- implement the server side of the

connection

Page 6: Ppt of socket

The InetAddress Class

O It converts the domain name of Internet address into an Object. This class represents an Internet Protocol (IP) address.

O Doesn’t have Constructors.

O Three static methods are used to create instances.O getLocalHost()O getByName(String hostName)O getAllByName(String hostName)

O All these methods throw UnknownHostException if the method cannot resolve the host name.

Page 7: Ppt of socket

getLocalHost()import java.net.*;class obtainIP{

public static void main(String args []) throws UnknownHostException{

InetAddress adr;adr=InetAddress.getLocalHost();System.out.println("\nInfo about Machine: " + adr);

}}

Page 8: Ppt of socket

getByName(String hostName)import java.io.*;

import java.net.*;class obtainIP2{ public static void main(String args []) throws IOException

{ InetAddress adr;String host;DataInputStream input=new DataInputStream(System.in);System.out.println("Enter the Machine's Hostname");host=input.readLine();

try {adr=InetAddress.getByName(host);System.out.println("\nInfo about Host \"" + host + "\" is:- " + adr);

}catch( UnknownHostException e) {

System.out.println("No such host exist"); }}

}

Page 9: Ppt of socket

Output

Page 10: Ppt of socket

getAllByName(String hostName)

import java.io.*;import java.net.*;class obtainIP3{public static void main(String args [ ]) throws IOException { InetAddress adr[]; int j=0; String host; DataInputStream input=new DataInputStream(System.in);

System.out.println("Enter host "); host=input.readLine();

try { adr=InetAddress.getAllByName(host); for(int i=0;i<adr.length;i++) { j++; System.out.println(j +"\t" + adr[i]); } }

catch( UnknownHostException e) { System.out.println("No such host exist"); }}}

Page 11: Ppt of socket

Output

Page 12: Ppt of socket

getAddress() & getHostName()

import java.net.*;class obtainIP4{ public static void main(String args []) throws UnknownHostException

{String msg;byte num[];InetAddress adr;adr=InetAddress.getLocalHost();num=adr.getAddress();msg=adr.getHostName();System.out.println("LocalHost= " + adr);for(int i=0;i<num.length;i++){

msg +=(num[i] & 255) + ".";System.out.println("Num= " + msg);

}}

}

Page 13: Ppt of socket

Output

Page 14: Ppt of socket

Socket ClassO The Socket class ,basically used to create client

sockets, is designed to connect to server socket and initiate protocol exchanges.

O When Socket object is created, it implicitly establishes the connection b/w client and server.

O Socket defines the constructors to create client sockets.

Constructors:-Socket(String hostname, int port);Socket(InetAdrress ipaddr, int port);

Page 15: Ppt of socket

Socket Class MethodsMethods:-

1)InputStream getInputStream();

2)OutputStream getOutputStream();

3)void close();

Page 16: Ppt of socket

ServerSocket ClassThe ServerSocket class, basically used to create server sockets, is designed to be a listener, which waits for client to connect before doing anything.

Constructors:-ServerSocket ( int port );ServerSocket ( int port, int queueLength);

Method:-Socket accept();

accept() is a blocking call that waits for a client to initiate communication and returns a normal Socket, that is used for communication with the client.

Page 17: Ppt of socket