DataGram Applet in java

Objective:

            Build an applet that sends a datagram to a server each time that it is started or stopped. Further build a server application that receives the sent datagram and prints it out

Packages used:

1. java.net.*         :Package used for coding in network connections.
2. java.applet.*    :Package  used while creating applet. Provides the classes necessary to create an applet and the classes an applet uses to communicate with its applet context.
3. java.awt.*;      :Contains all of the classes for creating user interfaces and for painting graphics and images.
4. java.awt.event.*: Provides interfaces and classes for dealing with different types of events fired by AWT components.

Classes used:

·         DatagramSocket : This class represents a socket for sending and receiving datagram packets.

·         DatagramPacket  : This class represents a datagram packet.

Logical flow of the program:

·         Server is created by DatagramSocket class.

·         When an applet is started, inside the start() method object of DatagramPacket is created. This object sends a message to server saying “Applet started”

·         When an applet is stopped,inside the stop() method object of DatagramPacket is created.This object sends a message to server saying “Applet stopped”.

Important notes:

1.      Open two command prompts for client and server respectively.

2.      Server side java code must be compiled and ececuted before compiling the client side java code.