Examples with DatagramChannel java.nio.channels.DatagramChannel used on opensource projects

Example 31 with DatagramChannel

use of java.nio.channels.DatagramChannel in project xian by happyyangyuan.

the class GelfUDPSender method connect.

protected void connect() throws IOException {
    if (isConnected()) {
        return;
    }
    if (channel() == null) {
        setChannel(DatagramChannel.open());
    } else if (!channel().isOpen()) {
        Closer.close(channel());
        setChannel(DatagramChannel.open());
    }
    channel().configureBlocking(false);
    InetSocketAddress inetSocketAddress = new InetSocketAddress(getHost(), getPort());
    try {
        DatagramChannel connect = channel().connect(inetSocketAddress);
        setChannel(connect);
    } catch (SocketException e) {
        reportError(e.getMessage(), e);
    }
}

Example 32 with DatagramChannel

use of java.nio.channels.DatagramChannel in project pi314.notes by pi314.

the class ToyVpnService method run.

private boolean run(InetSocketAddress server) throws Exception {
    DatagramChannel tunnel = null;
    boolean connected = false;
    try {
        // Create a DatagramChannel as the VPN tunnel.
        tunnel = DatagramChannel.open();
        // Protect the tunnel before connecting to avoid loopback.
        if (!protect(tunnel.socket())) {
            throw new IllegalStateException("Cannot protect the tunnel");
        }
        // Connect to the server.
        tunnel.connect(server);
        // For simplicity, we use the same thread for both reading and
        // writing. Here we put the tunnel into non-blocking mode.
        tunnel.configureBlocking(false);
        // Authenticate and configure the virtual network interface.
        handshake(tunnel);
        // Now we are connected. Set the flag and show the message.
        connected = true;
        mHandler.sendEmptyMessage(R.string.connected);
        // Packets to be sent are queued in this input stream.
        FileInputStream in = new FileInputStream(mInterface.getFileDescriptor());
        // Packets received need to be written to this output stream.
        FileOutputStream out = new FileOutputStream(mInterface.getFileDescriptor());
        // Allocate the buffer for a single packet.
        ByteBuffer packet = ByteBuffer.allocate(32767);
        // We use a timer to determine the status of the tunnel. It
        // works on both sides. A positive value means sending, and
        // any other means receiving. We start with receiving.
        int timer = 0;
        // We keep forwarding packets till something goes wrong.
        while (true) {
            // Assume that we did not make any progress in this iteration.
            boolean idle = true;
            // Read the outgoing packet from the input stream.
            int length = in.read(packet.array());
            if (length > 0) {
                // Write the outgoing packet to the tunnel.
                packet.limit(length);
                tunnel.write(packet);
                packet.clear();
                // There might be more outgoing packets.
                idle = false;
                // If we were receiving, switch to sending.
                if (timer < 1) {
                    timer = 1;
                }
            }
            // Read the incoming packet from the tunnel.
            length = tunnel.read(packet);
            if (length > 0) {
                // Ignore control messages, which start with zero.
                if (packet.get(0) != 0) {
                    // Write the incoming packet to the output stream.
                    out.write(packet.array(), 0, length);
                }
                packet.clear();
                // There might be more incoming packets.
                idle = false;
                // If we were sending, switch to receiving.
                if (timer > 0) {
                    timer = 0;
                }
            }
            // fraction of time to avoid busy looping.
            if (idle) {
                Thread.sleep(100);
                // Increase the timer. This is inaccurate but good enough,
                // since everything is operated in non-blocking mode.
                timer += (timer > 0) ? 100 : -100;
                // heartbeat
                if (timer < -15000) {
                    // Send empty control messages.
                    packet.put((byte) 0).limit(1);
                    for (int i = 0; i < 3; ++i) {
                        packet.position(0);
                        tunnel.write(packet);
                    }
                    packet.clear();
                    // Switch to sending.
                    timer = 1;
                }
                // We are sending for a long time but not receiving.
                if (timer > 20000) {
                    throw new IllegalStateException("Timed out");
                }
            }
        }
    } catch (InterruptedException e) {
        throw e;
    } catch (Exception e) {
        Log.e(TAG, "Got " + e.toString());
    } finally {
        try {
            tunnel.close();
        } catch (Exception e) {
        // ignore
        }
    }
    return connected;
}

Example 33 with DatagramChannel

use of java.nio.channels.DatagramChannel in project xian by happyyangyuan.

the class GelfUDPSender method initiateChannel.

private DatagramChannel initiateChannel() throws IOException {
    DatagramChannel resultingChannel = DatagramChannel.open();
    resultingChannel.socket().bind(new InetSocketAddress(0));
    resultingChannel.connect(new InetSocketAddress(this.host, this.port));
    resultingChannel.configureBlocking(false);
    return resultingChannel;
}

Example 34 with DatagramChannel

use of java.nio.channels.DatagramChannel in project xian by happyyangyuan.

the class GraylogUdpConnPool method initiateChannel.

private DatagramChannel initiateChannel() throws IOException {
    DatagramChannel resultingChannel = DatagramChannel.open();
    resultingChannel.socket().bind(new InetSocketAddress(0));
    resultingChannel.connect(new InetSocketAddress(this.host, port));
    resultingChannel.configureBlocking(false);
    return resultingChannel;
}

Example 35 with DatagramChannel

use of java.nio.channels.DatagramChannel in project reactor-netty by reactor.

the class UdpServerTests method supportsReceivingDatagrams.

@Test
@Ignore
public void supportsReceivingDatagrams() throws InterruptedException {
    final int port = SocketUtils.findAvailableUdpPort();
    final CountDownLatch latch = new CountDownLatch(4);
    final NettyContext server = UdpServer.create(port).newHandler((in, out) -> {
        in.receive().asByteArray().log().subscribe(bytes -> {
            if (bytes.length == 1024) {
                latch.countDown();
            }
        });
        return Flux.never();
    }).doOnSuccess(v -> {
        try {
            DatagramChannel udp = DatagramChannel.open();
            udp.configureBlocking(true);
            udp.connect(new InetSocketAddress(InetAddress.getLocalHost(), port));
            byte[] data = new byte[1024];
            new Random().nextBytes(data);
            for (int i = 0; i < 4; i++) {
                udp.write(ByteBuffer.wrap(data));
            }
            udp.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }).block(Duration.ofSeconds(30));
    assertThat("latch was counted down", latch.await(10, TimeUnit.SECONDS));
    server.dispose();
}