DatagramSocket and DatagramPacket in Java

DatagramSocket and DatagramPacket

Datagrams are bundles of information passed between machines. They are somewhat like a hard throw from a well-trained but blindfolded catcher to the third baseman. Once the datagram has been released to its intended target, there is no assurance that it will arrive or even that someone will be there to catch it.

Likewise, when the datagram is received, there is no assurance that it hasn’t been damaged in transit or that whoever sent it is still there to receive a response. Java implements datagrams on top of the UDP protocol by using two classes: the DatagramPacket object is the data container, while the DatagramSocket is the mechanism used to send or receive the DatagramPackets.

DatagramSocket in Java

DatagramSocket defines four public constructors:

DatagramSocket( ) throws SocketException
DatagramSocket(int port) throws SocketException
DatagramSocket(int port, InetAddress ipAddress) throws SocketException
DatagramSocket(SocketAddress address) throws SocketException

DatagramPacket in Java

DatagramPacket defines four constructors:

DatagramPacket(byte data[ ], int size)
DatagramPacket(byte data[ ], int offset, int size)
DatagramPacket(byte data[ ], int size, InetAddress ipAddress, int port)
DatagramPacket(byte data[ ], int offset, int size, InetAddress ipAddress, int port)