Example usage for java.util Deque offerLast

Introduction

In this page you can find the example usage for java.util Deque offerLast.

Prototype

boolean offerLast(E e);

Source Link

Document

Inserts the specified element at the end of this deque unless it would violate capacity restrictions.

Usage

From source file:Main.java

public static void main(String[] args) {
    Deque<String> deque = new LinkedList<>();
    deque.addLast("Oracle");
    deque.offerLast("Java");
    deque.offerLast("CSS");
    deque.offerLast("XML");

    System.out.println("Deque: " + deque);

    // remove elements from the Deque until it is empty
    while (deque.peekFirst() != null) {
        System.out.println("Head  Element: " + deque.peekFirst());
        deque.removeFirst();/*from   w  ww  .  jav a  2s. c  o m*/
        System.out.println("Removed one  element from  Deque");
        System.out.println("Deque: " + deque);
    }

    // the Deque is empty. Try to call its peekFirst(),
    // getFirst(), pollFirst() and removeFirst() methods
    System.out.println("deque.isEmpty(): " + deque.isEmpty());

    System.out.println("deque.peekFirst(): " + deque.peekFirst());
    System.out.println("deque.pollFirst(): " + deque.pollFirst());

    String str = deque.getFirst();
    System.out.println("deque.getFirst(): " + str);
    str = deque.removeFirst();
    System.out.println("deque.removeFirst(): " + str);

}

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From source file:Main.java

public static void main(String[] args) {

    Deque<Integer> deque = new ArrayDeque<Integer>(8);

    deque.add(1);/*from w  w  w  .java 2s  .c  o m*/
    deque.add(2);
    deque.add(3);
    deque.add(4);

    deque.offerLast(5);

    System.out.println(deque);
}

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From source file:com.mgmtp.perfload.core.console.status.StatusHandler.java

private void addThreadActivity(final Integer daemonId, final Integer processId, final int activeThreads) {
    StatusInfoKey key = new StatusInfoKey(daemonId, processId, null);

    Deque<ThreadActivity> taDeque = threadActivities.get(key);
    if (taDeque == null) {
        Deque<ThreadActivity> newDeque = new LinkedBlockingDeque<>();
        taDeque = threadActivities.putIfAbsent(key, newDeque);
        if (taDeque == null) {
            taDeque = newDeque;/*  w  w  w.  ja va2  s  . co  m*/
        }
    }
    String timestamp = TIMESTAMP_FORMAT.format(Calendar.getInstance());
    taDeque.offerLast(new ThreadActivity(daemonId, processId, activeThreads, timestamp));
}

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From source file:com.spotify.helios.client.DefaultRequestDispatcher.java

/**
 * Sets up a connection, retrying on connect failure.
 *//*w  ww . j a v  a  2s.c  o m*/
private HttpURLConnection connect(final URI uri, final String method, final byte[] entity,
        final Map<String, List<String>> headers)
        throws URISyntaxException, IOException, TimeoutException, InterruptedException, HeliosException {
    final long deadline = currentTimeMillis() + RETRY_TIMEOUT_MILLIS;
    final int offset = ThreadLocalRandom.current().nextInt();

    while (currentTimeMillis() < deadline) {
        final List<URI> endpoints = endpointSupplier.get();
        if (endpoints.isEmpty()) {
            throw new RuntimeException("failed to resolve master");
        }
        log.debug("endpoint uris are {}", endpoints);

        // Resolve hostname into IPs so client will round-robin and retry for multiple A records.
        // Keep a mapping of IPs to hostnames for TLS verification.
        final List<URI> ipEndpoints = Lists.newArrayList();
        final Map<URI, URI> ipToHostnameUris = Maps.newHashMap();

        for (final URI hnUri : endpoints) {
            try {
                final InetAddress[] ips = InetAddress.getAllByName(hnUri.getHost());
                for (final InetAddress ip : ips) {
                    final URI ipUri = new URI(hnUri.getScheme(), hnUri.getUserInfo(), ip.getHostAddress(),
                            hnUri.getPort(), hnUri.getPath(), hnUri.getQuery(), hnUri.getFragment());
                    ipEndpoints.add(ipUri);
                    ipToHostnameUris.put(ipUri, hnUri);
                }
            } catch (UnknownHostException e) {
                log.warn("Unable to resolve hostname {} into IP address: {}", hnUri.getHost(), e);
            }
        }

        for (int i = 0; i < ipEndpoints.size() && currentTimeMillis() < deadline; i++) {
            final URI ipEndpoint = ipEndpoints.get(positive(offset + i) % ipEndpoints.size());
            final String fullpath = ipEndpoint.getPath() + uri.getPath();

            final String scheme = ipEndpoint.getScheme();
            final String host = ipEndpoint.getHost();
            final int port = ipEndpoint.getPort();
            if (!VALID_PROTOCOLS.contains(scheme) || host == null || port == -1) {
                throw new HeliosException(String.format(
                        "Master endpoints must be of the form \"%s://heliosmaster.domain.net:<port>\"",
                        VALID_PROTOCOLS_STR));
            }

            final URI realUri = new URI(scheme, host + ":" + port, fullpath, uri.getQuery(), null);

            AgentProxy agentProxy = null;
            Deque<Identity> identities = Queues.newArrayDeque();
            try {
                if (scheme.equals("https")) {
                    agentProxy = AgentProxies.newInstance();
                    for (final Identity identity : agentProxy.list()) {
                        if (identity.getPublicKey().getAlgorithm().equals("RSA")) {
                            // only RSA keys will work with our TLS implementation
                            identities.offerLast(identity);
                        }
                    }
                }
            } catch (Exception e) {
                log.warn("Couldn't get identities from ssh-agent", e);
            }

            try {
                do {
                    final Identity identity = identities.poll();

                    try {
                        log.debug("connecting to {}", realUri);

                        final HttpURLConnection connection = connect0(realUri, method, entity, headers,
                                ipToHostnameUris.get(ipEndpoint).getHost(), agentProxy, identity);

                        final int responseCode = connection.getResponseCode();
                        if (((responseCode == HTTP_FORBIDDEN) || (responseCode == HTTP_UNAUTHORIZED))
                                && !identities.isEmpty()) {
                            // there was some sort of security error. if we have any more SSH identities to try,
                            // retry with the next available identity
                            log.debug("retrying with next SSH identity since {} failed", identity.getComment());
                            continue;
                        }

                        return connection;
                    } catch (ConnectException | SocketTimeoutException | UnknownHostException e) {
                        // UnknownHostException happens if we can't resolve hostname into IP address.
                        // UnknownHostException's getMessage method returns just the hostname which is a
                        // useless message, so log the exception class name to provide more info.
                        log.debug(e.toString());
                        // Connecting failed, sleep a bit to avoid hammering and then try another endpoint
                        Thread.sleep(200);
                    }
                } while (false);
            } finally {
                if (agentProxy != null) {
                    agentProxy.close();
                }
            }
        }
        log.warn("Failed to connect, retrying in 5 seconds.");
        Thread.sleep(5000);
    }
    throw new TimeoutException("Timed out connecting to master");
}

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