www.pudn.com > 20051122095286.zip > DatagramReceiver.java

package ora.ch6; 
 
import java.io.IOException; 
import javax.microedition.io.Connector; 
import javax.microedition.io.Datagram; 
import javax.microedition.io.DatagramConnection; 
 
public class DatagramReceiver { 
    public static void main(String[] args) { 
        if (args.length != 1) { 
            System.out.println("Usage: DatagramReceiver port"); 
            System.exit(1); 
        } 
         
        try { 
            DatagramConnection receiver =  
                    (DatagramConnection)Connector.open("datagram://:" + args[0]); 
            byte[] buffer = new byte[256]; 
            Datagram dgram = receiver.newDatagram(buffer, buffer.length); 
            for (;;) { 
                dgram.setLength(buffer.length); 
                receiver.receive(dgram); 
                int length = dgram.getLength(); 
                System.out.println("Datagram received. Length is " + length); 
 
                // Show the content of the datagram. 
                for (int i = 0; i < length; i++) { 
                    System.out.print(buffer[i] + " "); 
                } 
                System.out.println(); 
                 
                // Send it back... 
                receiver.send(dgram); 
            } 
        } catch (IOException ex) { 
            System.out.println("IOException: " + ex); 
        } 
    } 
}