import java.io.*;
import java.net.*;

public class AnimUDPServerColor0{
	public static void main(String args[]){
		// 受信パケットの雛形を作成
		byte req[] = new byte[32];
		DatagramPacket receivePacket = new DatagramPacket(req,req.length);

		try{
			// UDPソケット作成
			final int port = 8001;
			DatagramSocket socket = new DatagramSocket(port);
			System.out.println("Running...");

			while(true){
				// クライアント待受
				socket.receive(receivePacket);
				String fname = new String(req,0,receivePacket.getLength());

				// クライアントデータを取得して新しいパケットを作成
				byte buf[] = receivePacket.getData();
				InetAddress address = receivePacket.getAddress();
				int clientPort = receivePacket.getPort();
				DatagramPacket newPacket = new DatagramPacket(buf, buf.length, address, clientPort);

				// 別スレッドでデータを送信する
				DataSendThread dataSendThread = new DataSendThread(newPacket, fname);
				Thread thread = new Thread(dataSendThread);
				thread.start();
			}
		}
		catch(Exception e){
			System.out.println("Exception : " + e );
			e.printStackTrace();
		}
	}
}

// データ送信スレッド
class DataSendThread extends Thread {
	// Ack用パケット
	DatagramPacket receivePacket;
	// ファイル名
	String fname;

	DataSendThread(DatagramPacket receivePacket, String fname) {
		this.receivePacket = receivePacket;
		this.fname = fname;
	}

	public void run() {
		try {
			//送信用DatagramPaket
			byte buf[] = new byte[1200];
			DatagramPacket sendPacket = new DatagramPacket(buf,buf.length);

			// レスポンスに使うデータを取得
			InetAddress clientAddress = receivePacket.getAddress();
			int clientPort = receivePacket.getPort();

			// 新しいUDP Socket
			DatagramSocket socket2 = new DatagramSocket();

			// Ackを返す
			socket2.send(receivePacket);

			// sendPacketのIPaddress,PortNo,データ長設定
			sendPacket.setAddress(clientAddress);
			sendPacket.setPort(clientPort);
			sendPacket.setLength(1200);

			// 動画ファイルをストリームに変換
			System.out.println(fname);
			BufferedInputStream biStream = new BufferedInputStream(new FileInputStream(fname));

			while(true) {
				for(int i = 0; i < 48; i++){
					// 送信データ読み出し
					biStream.read(buf,0,1200);
					// パケット送信
					socket2.send(sendPacket);
					// Ack返す
					socket2.receive(receivePacket);
					// ストリームが空なら終了
					if(buf[0] < 0)break;
				}
				if(buf[0] < 0)break;
				// Ackを返す
				socket2.receive(receivePacket);
			}

			biStream.close();
			socket2.close();
		} catch (Exception e) {
			System.out.println("Exception : " + e );
			e.printStackTrace();
		}
	}
}