Socket programming in Java allows programs to communicate over a computer network. A socket provides an interface to send and receive data through ports on a host. The core java.net package contains classes for network programming including Socket, ServerSocket, DatagramSocket, and InetAddress. TCP sockets provide connection-oriented reliable data streams while UDP sockets provide unreliable datagram-based communication. Examples show how to create server and client sockets to exchange data for both TCP and UDP.

1. Socket programming
in java

2. PRESENTED BY:
Name: Zahidul Islam Razu
ID:011 132 047
Section : A
Course Title: Object Oriented Programming Lab
Course code : CSI 212

3. WHAT IS a socket?

4. Ports in socket
Each host has 65,536 ports
Some ports are reserved for specific apps
A socket provides an interface to send data
to/from the network through a port

5. Classes for socket
•ContentHandler
•DatagramPacket
•DatagramSocket
•DatagramSocketImplHttpURLConnection
•InetAddress
•MulticastSocket
•ServerSocket
•Socket
•SocketImpl
•URL
•URLConnection
•URLEncoder
•URLStreamHandler
The core package
java.net contains
a number of
classes that allow
programmers to
carry out network
programming

6. ExCEPTIONS FOR SOCKET

7. Types of socket

9. Example of t.c.p socket
Server
• Create a ServerSocket object
ServerSocket servSocket = new
ServerSocket(1234);
• Put the server into a waiting
state
Socket link =
servSocket.accept();
• Set up input and output streams
• use thread to serve this client
via link
• Send and receive data
out.println(awaiting data…);
String input = in.readLine();
• Close the connection
link.close()

10. Example of t.c.p socket
Client
• Establish a connection to the
server
Socket link =
new
Socket(<server>,<port>);
• Set up input and output
streams
• Send and receive data
• Close the connection

11. U.D.P socket
•unreliable delivery
•no order guarantees
•no notion of “connection”
•can send or receive

12. Example of u.d.p socket
SERVER
•Create a DatagramSocket object
DatagramSocket dgramSocket =
new DatagramSocket(1234);
•Create a buffer for incoming datagrams
byte[] buffer = new byte[256];
•Create a DatagramPacket object for the incoming
datagram
•DatagramPacket inPacket =
new DatagramPacket(buffer, buffer.length);
•Accept an incoming datagram
dgramSocket.receive(inPacket)
•Accept the sender’s address and port from the packet
InetAddress clientAddress = inPacket.getAddress();
int clientPort = inPacket.getPort();
•Retrieve the data from the buffer
string message =
new String(inPacket.getData(), 0,
inPacket.getLength());
•Create the response datagram
•DatagramPacket outPacket =
new DatagramPacket(
response.getBytes(),
response.length(),
clientAddress, clientPort);
•Send the response datagram
dgramSocket.send(outPacket)
•Close the DatagramSocket: dgram.close();

13. Example of u.d.p socket
CLIENT
• Create a DatagramSocket object
DatagramSocket dgramSocket = new
DatagramSocket;
• Create the outgoing datagram
DatagramPacket outPacket =
• new DatagramPacket(message.getBytes(),
message.length(),host, port);
• Send the datagram message
dgramSocket.send(outPacket)
• Create a buffer for incoming datagrams
byte[] buffer = new byte[256];
• Create a DatagramPacket object for the incoming
datagram
• DatagramPacket inPacket =
new DatagramPacket(buffer, buffer.length);
• Accept an incoming datagram
dgramSocket.receive(inPacket)
• Retrieve the data from the buffer
string response = new String(inPacket.getData(), 0,
inPacket.getLength());
• Close the DatagramSocket:
dgram.close();

14. Applications of socket

15. ANY QUESTIONS?
 Thank you.