Example usage for java.net DatagramPacket DatagramPacket

Introduction

In this page you can find the example usage for java.net DatagramPacket DatagramPacket.

Prototype

public DatagramPacket(byte buf[], int length) 

Source Link

Document

Constructs a DatagramPacket for receiving packets of length length .

Usage

From source file:Main.java

public static void main(String[] args) throws Exception {
    final int LOCAL_PORT = 12345;
    final String SERVER_NAME = "localhost";
    DatagramSocket udpSocket = new DatagramSocket(LOCAL_PORT, InetAddress.getByName(SERVER_NAME));

    System.out.println("Created UDP  server socket at " + udpSocket.getLocalSocketAddress() + "...");
    while (true) {
        System.out.println("Waiting for a  UDP  packet...");
        DatagramPacket packet = new DatagramPacket(new byte[1024], 1024);
        udpSocket.receive(packet);//from w ww.j ava2s  .c o  m
        displayPacketDetails(packet);
        udpSocket.send(packet);
    }
}

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From source file:Main.java

public static void main(String[] args) throws Exception {
    int mcPort = 12345;
    String mcIPStr = "230.1.1.1";
    MulticastSocket mcSocket = null;
    InetAddress mcIPAddress = null;
    mcIPAddress = InetAddress.getByName(mcIPStr);
    mcSocket = new MulticastSocket(mcPort);
    System.out.println("Multicast Receiver running at:" + mcSocket.getLocalSocketAddress());
    mcSocket.joinGroup(mcIPAddress);//from  ww  w . ja va 2 s  .c  om

    DatagramPacket packet = new DatagramPacket(new byte[1024], 1024);

    System.out.println("Waiting for a  multicast message...");
    mcSocket.receive(packet);
    String msg = new String(packet.getData(), packet.getOffset(), packet.getLength());
    System.out.println("[Multicast  Receiver] Received:" + msg);

    mcSocket.leaveGroup(mcIPAddress);
    mcSocket.close();
}

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From source file:UDPReceive.java

public static void main(String args[]) {
    try {/*from   w  w w.  j a v a2  s.c o  m*/
        int port = 90;

        // Create a socket to listen on the port.
        DatagramSocket dsocket = new DatagramSocket(port);

        // Create a buffer to read datagrams into. If a
        // packet is larger than this buffer, the
        // excess will simply be discarded!
        byte[] buffer = new byte[2048];

        // Create a packet to receive data into the buffer
        DatagramPacket packet = new DatagramPacket(buffer, buffer.length);

        // Now loop forever, waiting to receive packets and printing them.
        while (true) {
            // Wait to receive a datagram
            dsocket.receive(packet);

            // Convert the contents to a string, and display them
            String msg = new String(buffer, 0, packet.getLength());
            System.out.println(packet.getAddress().getHostName() + ": " + msg);

            // Reset the length of the packet before reusing it.
            packet.setLength(buffer.length);
        }
    } catch (Exception e) {
        System.err.println(e);
    }
}

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From source file:UDPReceive.java

public static void main(String args[]) {
    try {//from  w  w  w  . j  ava 2 s  .c o m
        if (args.length != 1)
            throw new IllegalArgumentException("Wrong number of args");

        // Get the port from the command line
        int port = Integer.parseInt(args[0]);

        // Create a socket to listen on the port.
        DatagramSocket dsocket = new DatagramSocket(port);

        // Create a buffer to read datagrams into. If anyone sends us a
        // packet containing more than will fit into this buffer, the
        // excess will simply be discarded!
        byte[] buffer = new byte[2048];

        // Create a packet to receive data into the buffer
        DatagramPacket packet = new DatagramPacket(buffer, buffer.length);

        // Now loop forever, waiting to receive packets and printing them.
        for (;;) {
            // Wait to receive a datagram
            dsocket.receive(packet);

            // Decode the bytes of the packet to characters, using the
            // UTF-8 encoding, and then display those characters.
            String msg = new String(buffer, 0, packet.getLength(), "UTF-8");
            System.out.println(packet.getAddress().getHostName() + ": " + msg);

            // Reset the length of the packet before reusing it.
            // Prior to Java 1.1, we'd just create a new packet each time.
            packet.setLength(buffer.length);
        }
    } catch (Exception e) {
        System.err.println(e);
        System.err.println(usage);
    }
}

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From source file:ChatClient.java

public static void main(String[] args) throws Exception {
        int PORT = 4000;
        byte[] buf = new byte[1000];
        DatagramPacket dgp = new DatagramPacket(buf, buf.length);
        DatagramSocket sk;//from w  w  w  .java2 s . co m

        sk = new DatagramSocket(PORT);
        System.out.println("Server started");
        while (true) {
            sk.receive(dgp);
            String rcvd = new String(dgp.getData(), 0, dgp.getLength()) + ", from address: " + dgp.getAddress()
                    + ", port: " + dgp.getPort();
            System.out.println(rcvd);

            BufferedReader stdin = new BufferedReader(new InputStreamReader(System.in));
            String outMessage = stdin.readLine();
            buf = ("Server say: " + outMessage).getBytes();
            DatagramPacket out = new DatagramPacket(buf, buf.length, dgp.getAddress(), dgp.getPort());
            sk.send(out);
        }
    }

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From source file:MulticastClient.java

 public static void main(String[] args) throws IOException {

   MulticastSocket socket = new MulticastSocket(4446);
   InetAddress address = InetAddress.getByName("230.0.0.1");
   socket.joinGroup(address);//from   ww  w.ja  va2  s .c om

   DatagramPacket packet;

   // get a few quotes
   for (int i = 0; i < 5; i++) {

      byte[] buf = new byte[256];
      packet = new DatagramPacket(buf, buf.length);
      socket.receive(packet);

      String received = new String(packet.getData());
      System.out.println("Quote of the Moment: " + received);
   }

   socket.leaveGroup(address);
   socket.close();
}

---

From source file:SDRecord.java

public static void main(String[] args) {

    boolean recordToInf = false;
    long recordTo = 0, txsize = 0, wr = 0, max = 0;
    int sourcePort = 0, destPort = 0;
    String val;
    OutputStream writer = null;/*from  w  ww .  j  a  va 2  s. c om*/
    InetAddress rhost = null, lhost = null;
    DatagramSocket socket = null;

    //Default values
    int buffSize = 1500;
    try {
        lhost = InetAddress.getByName("0.0.0.0");
    } catch (UnknownHostException e1) {
        System.err.println("ERROR!: Host not reconized");
        System.exit(3);
    }
    recordToInf = true;
    sourcePort = 7355;

    Options options = new Options();

    options.addOption("m", true, "Minutes to record, default is no limit");
    options.addOption("l", true, "Bind to a specific local address, default is 0.0.0.0");
    options.addOption("p", true, "Local port to use, default is 7355");
    options.addOption("r", true, "Remote address where to send data");
    options.addOption("d", true, "Remote port, to use with -r option");
    options.addOption("f", true, "Output file where to save the recording");
    options.addOption("s", true, "Stop recording when reaching specified MBs");
    options.addOption("h", false, "Help");

    CommandLineParser parser = new DefaultParser();
    CommandLine cmd = null;
    try {
        cmd = parser.parse(options, args);
    } catch (ParseException e1) {
        System.err.println("ERROR!: Error while parsing the command line");
        System.exit(1);
    }

    if (cmd.hasOption("m")) {
        val = cmd.getOptionValue("m");
        try {
            if (Long.parseLong(val) < 0) {
                System.err.println("ERROR!: -m argument value cannot be negative");
                System.exit(3);
            }
            recordTo = System.currentTimeMillis() + (Long.parseLong(val) * 60000);
            recordToInf = false;
        } catch (NumberFormatException e) {
            System.err.println("ERROR!: -m argument not an integer");
            System.exit(3);
        }
    }

    if (cmd.hasOption("l")) {
        val = cmd.getOptionValue("l");
        try {
            lhost = InetAddress.getByName(val);
        } catch (UnknownHostException e) {
            System.err.println("ERROR!: Host not reconized");
            System.exit(3);
        }
    }

    if (cmd.hasOption("p")) {
        val = cmd.getOptionValue("p");
        try {
            sourcePort = Integer.parseInt(val);
        } catch (NumberFormatException e) {
            System.err.println("ERROR!: -p argument not an integer");
            System.exit(3);
        }
    }

    if (cmd.hasOption("r")) {
        val = cmd.getOptionValue("r");
        try {
            rhost = InetAddress.getByName(val);
        } catch (UnknownHostException e) {
            System.err.println("ERROR!: Host not reconized");
            System.exit(3);
        }
    }

    if (cmd.hasOption("d")) {
        val = cmd.getOptionValue("d");
        try {
            destPort = Integer.parseInt(val);
        } catch (NumberFormatException e) {
            System.err.println("-ERROR!: -d argument not an integer");
            System.exit(3);
        }
    }

    if (cmd.hasOption("f")) {
        val = cmd.getOptionValue("f");
        try {
            writer = new FileOutputStream(val);
        } catch (FileNotFoundException e) {
            System.err.println("ERROR!: File not found");
            System.exit(3);
        }
    }

    if (cmd.hasOption("s")) {
        val = cmd.getOptionValue("s");

        try {
            max = (long) (Double.parseDouble(val) * 1000000);
        } catch (NumberFormatException e) {
            System.err.println("ERROR!: -s argument not valid");
            System.exit(3);
        }

        if (Double.parseDouble(val) < 0) {
            System.err.println("ERROR!: -s argument value cannot be negative");
            System.exit(3);
        }

    }

    if (cmd.hasOption("h")) {
        HelpFormatter formatter = new HelpFormatter();
        formatter.printHelp("SDRecord", options);
        System.exit(0);
    }

    try {
        socket = new DatagramSocket(sourcePort, lhost);
        //socket options
        socket.setReuseAddress(true);
    } catch (SocketException e) {
        e.printStackTrace();
        System.exit(3);
    }

    byte[] buffer = new byte[buffSize];
    DatagramPacket packet = new DatagramPacket(buffer, buffer.length);

    System.err.println("Listening " + lhost.toString() + " on port " + sourcePort);

    while (recordToInf == true || System.currentTimeMillis() <= recordTo) {
        //Stop recording when reaching max bytes
        if (max != 0 && txsize >= max)
            break;

        packet.setData(buffer);
        try {
            socket.receive(packet);
        } catch (IOException e) {
            e.printStackTrace();
            System.exit(4);
        }

        //Ignoring packets with no data
        if (basicFilter(packet) == null)
            continue;

        if (writer == null && rhost == null)
            wr = recordToStdout(packet);
        if (writer != null)
            wr = recordToFile(packet, writer);
        if (rhost != null)
            wr = recordToSocket(packet, socket, rhost, destPort);

        txsize += wr;
        System.err
                .print("\r" + formatSize(txsize) + " transferred" + "\033[K" + "\t Press Ctrl+c to terminate");
    }
    //closing socket and exit
    System.err.print("\r" + formatSize(txsize) + " transferred" + "\033[K");
    socket.close();
    System.out.println();
    System.exit(0);
}

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From source file:Main.java

private static DatagramPacket getRequestPacket() {
    String request = "00002";
    byte[] start_request_array = request.getBytes();
    DatagramPacket request_packet = new DatagramPacket(start_request_array, start_request_array.length);
    return request_packet;
}

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From source file:Main.java

private static void receive(Map<Integer, byte[]> map, DatagramSocket socket, int[] length) {
    byte[] b = new byte[limit + 4];
    DatagramPacket p = new DatagramPacket(b, b.length);
    try {/*w  w  w . ja  va2 s . c o  m*/
        socket.receive(p);
    } catch (IOException ex) {
        ex.printStackTrace();
    }
    if (p.getLength() != 0) {
        ByteBuffer buf = ByteBuffer.wrap(b);
        int key = buf.getInt();
        byte[] bytes = new byte[p.getLength() - 4];
        length[0] += bytes.length;
        buf.get(bytes);
        map.put(key, bytes);
        receive(map, socket, length);
    }
}

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From source file:Main.java

public static DatagramPacket getPacket(String msg) throws UnknownHostException {
    int PACKET_MAX_LENGTH = 1024;
    byte[] msgBuffer = msg.getBytes();

    int length = msgBuffer.length;
    if (length > PACKET_MAX_LENGTH) {
        length = PACKET_MAX_LENGTH;/*from  ww w .  ja va  2 s .co  m*/
    }
    DatagramPacket packet = new DatagramPacket(msgBuffer, length);
    InetAddress serverIPAddress = InetAddress.getByName("localhost");
    packet.setAddress(serverIPAddress);
    packet.setPort(15900);
    return packet;
}

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