Unicast messaging is used for all network processes in which a private or unique resource is requested.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 | import java.awt.*;import java.awt.event.*;import java.net.*;import javax.swing.JFrame;public class Unicast extends JFrame implements ActionListener{ Label entermsgl,receivedmsgl,sentmsgl,toportl; TextField entermsg,toport; TextArea receivedmsg,sentmsg; Button send,exit; int myport; DatagramSocket ds; DatagramPacket dp; Unicast(){ new InputDialog(this); } public void initialise(){ setTitle("Unicast --Port:"+myport); setVisible(true); setSize(600,400); entermsgl=new Label("Enter Message:"); receivedmsgl=new Label("Received Messages:"); sentmsgl=new Label("Sent Messages:"); toportl=new Label("To"); toport=new TextField(); entermsg=new TextField(); receivedmsg=new TextArea(); sentmsg=new TextArea(); send=new Button("Send"); exit=new Button("Exit"); setLayout(null); add(entermsgl); entermsgl.setBounds(25,25,100,25); add(receivedmsgl); receivedmsgl.setBounds(25,70,150,25); add(sentmsgl); sentmsgl.setBounds(25,185,150,25); add(toportl); toportl.setBounds(350,25,25,25); add(toport); toport.setBounds(380,25,70,25); add(entermsg); entermsg.setBounds(130,25,200,25); add(receivedmsg); receivedmsg.setBounds(180,70,370,100); add(sentmsg); sentmsg.setBounds(180,185,370,100); add(send); send.setBounds(470,25,100,25); add(exit); exit.setBounds(250,300,100,25); try{ ds=new DatagramSocket(myport); }catch(Exception e){ System.out.println(e); } send.addActionListener(this); exit.addActionListener(this); new Receive(); } class Receive extends Thread{ Receive(){ start(); } public void run(){ while(true){ try{ byte b[]=new byte[100]; dp=new DatagramPacket(b,b.length); ds.receive(dp); receivedmsg.append("From "+dp.getPort()+": "+new String(dp.getData(),0,dp.getLength())+"n"); }catch(Exception e){ } } } } public void actionPerformed(ActionEvent ae){ if(ae.getSource()==send){ byte b[]=entermsg.getText().getBytes(); try{ int port=Integer.parseInt(toport.getText()); if(port<1024 || port>65536){ toport.setText(""); return; } dp=new DatagramPacket(b,b.length,InetAddress.getLocalHost(),port); ds.send(dp); sentmsg.append("To "+port+": "+entermsg.getText()+"n"); }catch(NumberFormatException nfe){ toport.setText(""); }catch(Exception e){ } } else{ System.exit(0); } } public static void main(String args[]){ new Unicast(); }}class InputDialog extends Dialog implements ActionListener{ Button ok=new Button("Ok"); Button cancel=new Button("Cancel"); TextField tf=new TextField(); Label l=new Label("Enter the port number:"); Unicast parent; InputDialog(Unicast f){ super(f,"Unicast - Port number"); parent=f; setVisible(true); setSize(400,200); setLayout(null); add(l); l.setBounds(25,50,200,25); add(tf); tf.setBounds(225,50,100,25); add(ok); ok.setBounds(100,100,100,25); add(cancel); cancel.setBounds(220,100,100,25); ok.addActionListener(this); cancel.addActionListener(this); } public void actionPerformed(ActionEvent ae){ if(ae.getSource()==ok){ try{ int n=Integer.parseInt(tf.getText()); if(n>1023 && n<65536){ parent.myport=n; parent.initialise(); this.dispose(); } else{ tf.setText(""); tf.requestFocus(); } }catch(NumberFormatException nfe){ tf.setText(""); tf.requestFocus(); } } else if(ae.getSource()==cancel){ System.exit(0); } }} |
