Open NetBeans and do the following:
1. Create a new project named UdpClient
2. Import java.net.* and java.io.*
3. Inside the main method type these statements:
public static void main(String args[])
{
DatagramSocket sock = null;
int port = 7777;
String s;
BufferedReader cin = new BufferedReader(new InputStreamReader(System.in));
try
{
sock = new DatagramSocket();
InetAddress host = InetAddress.getByName("localhost");
while(true)
{
//take input and send the packet
echo("Enter message to send : ");
s = (String)cin.readLine();
byte[] b = s.getBytes();
DatagramPacket dp = new DatagramPacket(b , b.length , host , port);
sock.send(dp);
//now receive reply
//buffer to receive incoming data
byte[] buffer = new byte[65536];
DatagramPacket reply = new DatagramPacket(buffer, buffer.length);
sock.receive(reply);
byte[] data = reply.getData();
s = new String(data, 0, reply.getLength());
//echo the details of incoming data - client ip : client port - client message
echo(reply.getAddress().getHostAddress() + " : " + reply.getPort() + " - " + s);
}
}
catch(IOException e)
{
System.err.println("IOException " + e);
}
}
//simple function to echo data to terminal
public static void echo(String msg)
{
System.out.println(msg);
}
}
4. Create a new project named UdpServer
5. Import java.net.* and java.io.*
6. Inside the main method type these statements:
public static void main(String args[])
{
DatagramSocket sock = null;
try
{
//1. creating a server socket, parameter is local port number
sock = new DatagramSocket(7777);
//buffer to receive incoming data
byte[] buffer = new byte[65536];
DatagramPacket incoming = new DatagramPacket(buffer, buffer.length);
//2. Wait for an incoming data
echo("Server socket created. Waiting for incoming data...");
//communication loop
while(true)
{
sock.receive(incoming);
byte[] data = incoming.getData();
String s = new String(data, 0, incoming.getLength());
//echo the details of incoming data - client ip : client port - client message
echo(incoming.getAddress().getHostAddress() + " : " + incoming.getPort() + " - " + s);
s = "OK : " + s;
DatagramPacket dp = new DatagramPacket(s.getBytes() , s.getBytes().length , incoming.getAddress() , incoming.getPort());
sock.send(dp);
}
}
catch(IOException e)
{
System.err.println("IOException " + e);
}
}
//simple function to echo data to terminal
public static void echo(String msg)
{
System.out.println(msg);
}
}
7. Run UdpClient and UdpServer
d7dcq9
lab5.docx
0
