Examples with DatagramSocket java.net.DatagramSocket used on opensource projects

Example 31 with DatagramSocket

use of java.net.DatagramSocket in project hbase by apache.

the class HBaseTestingUtility method available.

/**
   * Checks to see if a specific port is available.
   *
   * @param port the port number to check for availability
   * @return <tt>true</tt> if the port is available, or <tt>false</tt> if not
   */
public static boolean available(int port) {
    ServerSocket ss = null;
    DatagramSocket ds = null;
    try {
        ss = new ServerSocket(port);
        ss.setReuseAddress(true);
        ds = new DatagramSocket(port);
        ds.setReuseAddress(true);
        return true;
    } catch (IOException e) {
    // Do nothing
    } finally {
        if (ds != null) {
            ds.close();
        }
        if (ss != null) {
            try {
                ss.close();
            } catch (IOException e) {
            /* should not be thrown */
            }
        }
    }
    return false;
}

Example 32 with DatagramSocket

use of java.net.DatagramSocket in project zookeeper by apache.

the class LeaderElection method lookForLeader.

/**
     * Invoked in QuorumPeer to find or elect a new leader.
     * 
     * @throws InterruptedException
     */
public Vote lookForLeader() throws InterruptedException {
    try {
        self.jmxLeaderElectionBean = new LeaderElectionBean();
        MBeanRegistry.getInstance().register(self.jmxLeaderElectionBean, self.jmxLocalPeerBean);
    } catch (Exception e) {
        LOG.warn("Failed to register with JMX", e);
        self.jmxLeaderElectionBean = null;
    }
    try {
        self.setCurrentVote(new Vote(self.getId(), self.getLastLoggedZxid()));
        // We are going to look for a leader by casting a vote for ourself
        byte[] requestBytes = new byte[4];
        ByteBuffer requestBuffer = ByteBuffer.wrap(requestBytes);
        byte[] responseBytes = new byte[28];
        ByteBuffer responseBuffer = ByteBuffer.wrap(responseBytes);
        /* The current vote for the leader. Initially me! */
        DatagramSocket s = null;
        try {
            s = new DatagramSocket();
            s.setSoTimeout(200);
        } catch (SocketException e1) {
            LOG.error("Socket exception when creating socket for leader election", e1);
            System.exit(4);
        }
        DatagramPacket requestPacket = new DatagramPacket(requestBytes, requestBytes.length);
        DatagramPacket responsePacket = new DatagramPacket(responseBytes, responseBytes.length);
        int xid = epochGen.nextInt();
        while (self.isRunning()) {
            HashMap<InetSocketAddress, Vote> votes = new HashMap<InetSocketAddress, Vote>(self.getVotingView().size());
            requestBuffer.clear();
            requestBuffer.putInt(xid);
            requestPacket.setLength(4);
            HashSet<Long> heardFrom = new HashSet<Long>();
            for (QuorumServer server : self.getVotingView().values()) {
                LOG.info("Server address: " + server.addr);
                try {
                    requestPacket.setSocketAddress(server.addr);
                } catch (IllegalArgumentException e) {
                    // in order to capture this critical detail.
                    throw new IllegalArgumentException("Unable to set socket address on packet, msg:" + e.getMessage() + " with addr:" + server.addr, e);
                }
                try {
                    s.send(requestPacket);
                    responsePacket.setLength(responseBytes.length);
                    s.receive(responsePacket);
                    if (responsePacket.getLength() != responseBytes.length) {
                        LOG.error("Got a short response: " + responsePacket.getLength());
                        continue;
                    }
                    responseBuffer.clear();
                    int recvedXid = responseBuffer.getInt();
                    if (recvedXid != xid) {
                        LOG.error("Got bad xid: expected " + xid + " got " + recvedXid);
                        continue;
                    }
                    long peerId = responseBuffer.getLong();
                    heardFrom.add(peerId);
                    //if(server.id != peerId){
                    Vote vote = new Vote(responseBuffer.getLong(), responseBuffer.getLong());
                    InetSocketAddress addr = (InetSocketAddress) responsePacket.getSocketAddress();
                    votes.put(addr, vote);
                //}
                } catch (IOException e) {
                    LOG.warn("Ignoring exception while looking for leader", e);
                // Errors are okay, since hosts may be
                // down
                }
            }
            ElectionResult result = countVotes(votes, heardFrom);
            // for a dead peer                 
            if (result.numValidVotes == 0) {
                self.setCurrentVote(new Vote(self.getId(), self.getLastLoggedZxid()));
            } else {
                if (result.winner.getId() >= 0) {
                    self.setCurrentVote(result.vote);
                    // To do: this doesn't use a quorum verifier
                    if (result.winningCount > (self.getVotingView().size() / 2)) {
                        self.setCurrentVote(result.winner);
                        s.close();
                        Vote current = self.getCurrentVote();
                        LOG.info("Found leader: my type is: " + self.getLearnerType());
                        /*
                             * We want to make sure we implement the state machine
                             * correctly. If we are a PARTICIPANT, once a leader
                             * is elected we can move either to LEADING or 
                             * FOLLOWING. However if we are an OBSERVER, it is an
                             * error to be elected as a Leader.
                             */
                        if (self.getLearnerType() == LearnerType.OBSERVER) {
                            if (current.getId() == self.getId()) {
                                // This should never happen!
                                LOG.error("OBSERVER elected as leader!");
                                Thread.sleep(100);
                            } else {
                                self.setPeerState(ServerState.OBSERVING);
                                Thread.sleep(100);
                                return current;
                            }
                        } else {
                            self.setPeerState((current.getId() == self.getId()) ? ServerState.LEADING : ServerState.FOLLOWING);
                            if (self.getPeerState() == ServerState.FOLLOWING) {
                                Thread.sleep(100);
                            }
                            return current;
                        }
                    }
                }
            }
            Thread.sleep(1000);
        }
        return null;
    } finally {
        try {
            if (self.jmxLeaderElectionBean != null) {
                MBeanRegistry.getInstance().unregister(self.jmxLeaderElectionBean);
            }
        } catch (Exception e) {
            LOG.warn("Failed to unregister with JMX", e);
        }
        self.jmxLeaderElectionBean = null;
    }
}

Example 33 with DatagramSocket

use of java.net.DatagramSocket in project zookeeper by apache.

the class QuorumPeer method startLeaderElection.

public synchronized void startLeaderElection() {
    try {
        if (getPeerState() == ServerState.LOOKING) {
            currentVote = new Vote(myid, getLastLoggedZxid(), getCurrentEpoch());
        }
    } catch (IOException e) {
        RuntimeException re = new RuntimeException(e.getMessage());
        re.setStackTrace(e.getStackTrace());
        throw re;
    }
    //}
    if (electionType == 0) {
        try {
            udpSocket = new DatagramSocket(myQuorumAddr.getPort());
            responder = new ResponderThread();
            responder.start();
        } catch (SocketException e) {
            throw new RuntimeException(e);
        }
    }
    this.electionAlg = createElectionAlgorithm(electionType);
}

Example 34 with DatagramSocket

use of java.net.DatagramSocket in project android by cSploit.

the class PacketForger method onClick.

@Override
public void onClick(View v) {
    if (!mRunning) {
        if (v.getId() == R.id.sendButton) {
            mResponse.setText("");
            mRunning = true;
            mThread = new Thread(new Runnable() {

                @Override
                public void run() {
                    int protocol = mProtocol.getSelectedItemPosition(), port = -1;
                    String data = mData.getText() + "", error = null;
                    boolean waitResponse = mWaitResponse.isChecked();
                    try {
                        port = Integer.parseInt(mPort.getText() + "".trim());
                        if (port <= 0 || port > 65535)
                            port = -1;
                    } catch (Exception e) {
                        port = -1;
                    }
                    if (port == -1)
                        error = getString(R.string.invalid_port);
                    else if (data.isEmpty())
                        error = getString(R.string.request_empty);
                    else {
                        try {
                            if (protocol == TCP_PROTOCOL) {
                                mSocket = new Socket(System.getCurrentTarget().getCommandLineRepresentation(), port);
                                OutputStream writer = mSocket.getOutputStream();
                                writer.write(data.getBytes());
                                writer.flush();
                                if (waitResponse) {
                                    BufferedReader reader = new BufferedReader(new InputStreamReader(mSocket.getInputStream()));
                                    String line;
                                    final StringBuilder responseBuilder = new StringBuilder();
                                    while ((line = reader.readLine()) != null) {
                                        responseBuilder.append(line).append("\n");
                                    }
                                    final String text = responseBuilder.toString();
                                    PacketForger.this.runOnUiThread(new Runnable() {

                                        public void run() {
                                            mResponse.setText(text);
                                        }
                                    });
                                    reader.close();
                                }
                                writer.close();
                                mSocket.close();
                            } else if (protocol == UDP_PROTOCOL) {
                                mUdpSocket = new DatagramSocket();
                                DatagramPacket packet = null;
                                if (mBinaryData != null)
                                    packet = new DatagramPacket(mBinaryData, mBinaryData.length, System.getCurrentTarget().getAddress(), port);
                                else
                                    packet = new DatagramPacket(data.getBytes(), data.length(), System.getCurrentTarget().getAddress(), port);
                                mUdpSocket.send(packet);
                                if (waitResponse) {
                                    byte[] buffer = new byte[1024];
                                    DatagramPacket response = new DatagramPacket(buffer, buffer.length);
                                    mUdpSocket.receive(response);
                                    final String text = new String(buffer);
                                    PacketForger.this.runOnUiThread(new Runnable() {

                                        public void run() {
                                            mResponse.setText(text);
                                        }
                                    });
                                }
                                mUdpSocket.close();
                            }
                        } catch (Exception e) {
                            error = e.getMessage();
                        }
                    }
                    mBinaryData = null;
                    final String errorMessage = error;
                    PacketForger.this.runOnUiThread(new Runnable() {

                        public void run() {
                            Toast.makeText(PacketForger.this, getString(R.string.request_sent), Toast.LENGTH_SHORT).show();
                            setStoppedState(errorMessage);
                        }
                    });
                }
            });
            mThread.start();
        } else {
            Endpoint endpoint = System.getCurrentTarget().getEndpoint();
            byte[] mac = endpoint.getHardware();
            int i;
            if (mac != null) {
                mResponse.setText("");
                mProtocol.setSelection(UDP_PROTOCOL);
                mPort.setText("9");
                mBinaryData = new byte[6 + 16 * mac.length];
                for (i = 0; i < 6; i++) {
                    mBinaryData[i] = (byte) 0xFF;
                }
                for (i = 6; i < mBinaryData.length; i += mac.length) {
                    java.lang.System.arraycopy(mac, 0, mBinaryData, i, mac.length);
                }
                final StringBuilder hexBuilder = new StringBuilder();
                for (i = 0; i < mBinaryData.length; i++) hexBuilder.append("\\x").append(Integer.toHexString(0xFF & mBinaryData[i]).toUpperCase());
                mData.setText(hexBuilder.toString());
                Toast.makeText(this, getString(R.string.customize_wol_port), Toast.LENGTH_SHORT).show();
            } else
                Toast.makeText(this, getString(R.string.couldnt_send_wol_packet), Toast.LENGTH_SHORT).show();
        }
    } else {
        setStoppedState(null);
    }
}

Example 35 with DatagramSocket

use of java.net.DatagramSocket in project jcollectd by collectd.

the class UdpReceiver method getSocket.

public DatagramSocket getSocket() throws IOException {
    if (_socket == null) {
        if (_bindAddress == null) {
            _socket = new DatagramSocket(_port);
        } else {
            InetAddress addr = InetAddress.getByName(_bindAddress);
            if (addr.isMulticastAddress()) {
                MulticastSocket mcast = new MulticastSocket(_port);
                if (_ifAddress != null) {
                    mcast.setInterface(InetAddress.getByName(_ifAddress));
                }
                mcast.joinGroup(addr);
                _socket = mcast;
            } else {
                _socket = new DatagramSocket(_port, addr);
            }
        }
    }
    return _socket;
}