import java.net.*; 
import javax.sound.sampled.*; 

public class Phone { 
  public static final AudioFormat FORMAT = new AudioFormat(AudioFormat.Encoding.PCM_SIGNED, 8000.0f, 16, 1, 2, 8000.0f, true); 
  public static final int PORT = 6000; 

  public static void main(String[] args) { 
    new Phone(args); 
  } 

  public Phone(String[] args) { 
    DatagramSocket socket = null; 
    DatagramPacket packet = new DatagramPacket(new byte[]{1}, 1); 
    InetAddress remote = null; 
    try {     
      if (args.length == 0) { 
        System.out.println("Waiting for partner..."); 
        socket = new DatagramSocket(PORT); 
        socket.receive(packet); 
        socket.connect(packet.getAddress(), PORT); 
      } else { 
        socket = new DatagramSocket(PORT); 
        socket.connect(InetAddress.getByName(args[0]), PORT); 
      } 
    } catch(Exception e) { 
      System.out.println(e);
    } 
    System.out.println("Connected to partner..."); 
    new Recorder(socket); 
    new Player(socket); 
  } 
} 

class Recorder extends Thread {
  private TargetDataLine line = null;
  private DatagramSocket socket = null;
  private InetAddress address= null;
   
  public Recorder(DatagramSocket socket) {
    this.socket = socket;
    address = socket.getInetAddress();
    start();
  }
 
  public void run() {   
    DataLine.Info info = new DataLine.Info(TargetDataLine.class, Phone.FORMAT); 

    try {
      line = (TargetDataLine)AudioSystem.getLine(info); 
      line.open(Phone.FORMAT, line.getBufferSize()); 
    } catch (Exception e) {  
      System.out.println(e); 
    } 

    int frameSizeInBytes = Phone.FORMAT.getFrameSize(); 
    int bufferLengthInFrames = line.getBufferSize() / 8; 
    int bufferLengthInBytes = bufferLengthInFrames * frameSizeInBytes; 
    int minPacketSize = (int)(bufferLengthInBytes / 10.5); 
    byte[] data; 
    int bytesAvailable; 

    line.start(); 
    System.out.println("Record started..."); 
    while(true) { 
      // Send data only when we have a buffer of at least 50% 
      if ((bytesAvailable = line.available()) >= minPacketSize) { 
        data = new byte[bytesAvailable]; 
        line.read(data, 0, bytesAvailable);  
        try { 
          socket.send(new DatagramPacket(data, bytesAvailable)); 
        } catch(Exception e) { 
          System.out.println(e); 
        } 
      }
    }
/*
    line.stop(); 
    line.flush(); 
    line.close(); 
    line = null;
*/
  } 
} 
 
class Player extends Thread {
  public final int BUFFER = 8000; 
   
  private SourceDataLine line = null; 
  private DatagramSocket socket = null; 
   
  public Player(DatagramSocket socket) { 
    this.socket = socket;
    start();
  }
   
  public void run() { 
    DataLine.Info info = new DataLine.Info(SourceDataLine.class, Phone.FORMAT);

    try { 
        line = (SourceDataLine)AudioSystem.getLine(info); 
        line.open(Phone.FORMAT, BUFFER); 
    } catch(Exception e) {  
        System.out.println(e); 
    } 
    line.start(); 
    DatagramPacket packet = new DatagramPacket(new byte[65536], 65536); 
    System.out.println("Play started..."); 
    while(true) { 
      try { 
        socket.receive(packet); 
      } catch(Exception e) { 
        System.out.println(e); 
      } 
      line.write(packet.getData(), 0, packet.getLength()); 
      packet = new DatagramPacket(new byte[65536], 65536); 
      //yield(); 
    } 
/*
    line.stop(); 
    line.flush(); 
    line.close(); 
    line = null;
*/
  } 
}