Example usage for java.util Collections shuffle

List of usage examples for java.util Collections shuffle

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Introduction

In this page you can find the example usage for java.util Collections shuffle.

Prototype

public static void shuffle(List<?> list)

Source Link

Document

Randomly permutes the specified list using a default source of randomness.

Usage

From source file:com.graphaware.neo4j.webexpo.database.DataGenerator.java

private String[] randomNumberOfRandomTopics(List<String> allTopics) {
    if (allTopics.size() < MAX_NUMBER_OF_INTERESTS) {
        throw new IllegalStateException("There must be at least " + MAX_NUMBER_OF_INTERESTS + " topics");
    }/*from   w ww .ja va2s .  co m*/

    Collections.shuffle(allTopics);

    int numberOfTopics = random.nextInt(MAX_NUMBER_OF_INTERESTS) + 1; //at least 1 topic, maximum MAX_NUMBER_OF_INTERESTS
    String[] randomTopics = new String[numberOfTopics];
    for (int i = 0; i < numberOfTopics; i++) {
        randomTopics[i] = allTopics.get(i);
    }

    return randomTopics;
}

From source file:edu.berkeley.sparrow.daemon.scheduler.Scheduler.java

/** Adds constraints such that tasks in the job will be spread evenly across the cluster.
 *
 *  We expect three of these special jobs to be submitted; 3 sequential calls to this
 *  method will result in spreading the tasks for the 3 jobs across the cluster such that no
 *  more than 1 task is assigned to each machine.
 *///from  w w  w.ja  v a2s .  co  m
private TSchedulingRequest addConstraintsToSpreadTasks(TSchedulingRequest req) throws TException {
    LOG.info("Handling spread tasks request: " + req);
    int specialCaseIndex = specialCaseCounter.incrementAndGet();
    if (specialCaseIndex < 1 || specialCaseIndex > 3) {
        LOG.error("Invalid special case index: " + specialCaseIndex);
    }

    // No tasks have preferences and we have the magic number of tasks
    TSchedulingRequest newReq = new TSchedulingRequest();
    newReq.user = req.user;
    newReq.app = req.app;
    newReq.probeRatio = req.probeRatio;

    List<InetSocketAddress> allBackends = Lists.newArrayList();
    List<InetSocketAddress> backends = Lists.newArrayList();
    // We assume the below always returns the same order (invalid assumption?)
    for (InetSocketAddress backend : state.getBackends(req.app)) {
        allBackends.add(backend);
    }

    // Each time this is called, we restrict to 1/3 of the nodes in the cluster
    for (int i = 0; i < allBackends.size(); i++) {
        if (i % 3 == specialCaseIndex - 1) {
            backends.add(allBackends.get(i));
        }
    }
    Collections.shuffle(backends);

    if (!(allBackends.size() >= (req.getTasks().size() * 3))) {
        LOG.error("Special case expects at least three times as many machines as tasks.");
        return null;
    }
    LOG.info(backends);
    for (int i = 0; i < req.getTasksSize(); i++) {
        TTaskSpec task = req.getTasks().get(i);
        TTaskSpec newTask = new TTaskSpec();
        newTask.message = task.message;
        newTask.taskId = task.taskId;
        newTask.preference = new TPlacementPreference();
        newTask.preference.addToNodes(backends.get(i).getHostName());
        newReq.addToTasks(newTask);
    }
    LOG.info("New request: " + newReq);
    return newReq;
}

From source file:ch.epfl.eagle.daemon.nodemonitor.NodeMonitor.java

public void requestTaskReservations() {
    LOG.info(Logging.functionCall());/* w w  w  .j  a v  a  2 s  .  co  m*/
    // 1. call sendTaskReservations to n workers
    List<InetSocketAddress> listBackends = getCleanWorkersList();
    // Get the big partition
    LOG.debug("STEALING: Initial node list size: " + listBackends.size());
    int last_nodeID = (int) (listBackends.size() * bigPartition / 100);
    listBackends = listBackends.subList(0, last_nodeID);
    LOG.debug("STEALING: Using nodes from 0 to " + last_nodeID + ". List consists of : " + listBackends);

    LOG.debug("STEALING: New list of backends " + listBackends.toString());
    Collections.shuffle(listBackends);
    InetSocketAddress chosenBackend = listBackends.get(0);

    try {
        InternalService.AsyncClient client = nodeMonitorClientPool.borrowClient(chosenBackend);
        stealingAttempts++;
        LOG.debug("STEALING: Launching sendTasksReservations on node: " + chosenBackend + " stealing attempts"
                + stealingAttempts);
        client.sendTasksReservations(new SendTaskReservationsCallback(chosenBackend, client));
        LOG.debug("STEALING: Finished launching sendTasksReservations on node: " + chosenBackend);
    } catch (Exception e) {
        LOG.error("Error enqueuing task on node " + chosenBackend.toString() + ":" + e);
    }

}

From source file:cm.aptoide.pt.MainActivity.java

private void loadUIEditorsApps() {

    final int[] res_ids = { R.id.central, R.id.topleft, R.id.topright, R.id.bottomleft, R.id.bottomcenter,
            R.id.bottomright };//from ww  w.  jav a2 s .  c  o  m
    final ArrayList<HashMap<String, String>> image_urls = db.getFeaturedGraphics();
    final HashMap<String, String> image_url_highlight = db.getHighLightFeature();

    //        System.out.println(image_url_highlight + "ASDASDASDASD");
    //        System.out.println(image_urls + "ASDASDASDASD");

    runOnUiThread(new Runnable() {
        @Override
        public void run() {
            if (image_url_highlight.size() > 0) {
                a = 1;
                ImageView v = (ImageView) featuredView.findViewById(res_ids[0]);
                // imageLoader.DisplayImage(-1, image_url_highlight.get("url"), v,
                // mContext);
                DisplayImageOptions options = new DisplayImageOptions.Builder()
                        .displayer(new FadeInBitmapDisplayer(1000)).cacheOnDisc().cacheInMemory().build();
                cm.aptoide.com.nostra13.universalimageloader.core.ImageLoader.getInstance()
                        .displayImage(image_url_highlight.get("url"), v, options);
                v.setTag(image_url_highlight.get("id"));
                v.setOnClickListener(new OnClickListener() {

                    @Override
                    public void onClick(View arg0) {

                        Intent i = new Intent(MainActivity.this, ApkInfo.class);
                        i.putExtra("_id", Long.parseLong((String) arg0.getTag()));
                        i.putExtra("top", false);
                        i.putExtra("category", Category.EDITORSCHOICE.ordinal());
                        startActivity(i);

                    }
                });
                // v.setOnClickListener(featuredListener);
            }
        }
    });

    Collections.shuffle(image_urls);
    runOnUiThread(new Runnable() {

        public void run() {

            for (int i = a; i != res_ids.length; i++) {
                try {
                    ImageView v = (ImageView) featuredView.findViewById(res_ids[i]);

                    // imageLoader.DisplayImage(-1,
                    // image_urls.get(i).get("url"), v, mContext);
                    DisplayImageOptions options = new DisplayImageOptions.Builder()
                            .displayer(new FadeInBitmapDisplayer(1000)).cacheOnDisc().cacheInMemory().build();
                    cm.aptoide.com.nostra13.universalimageloader.core.ImageLoader.getInstance()
                            .displayImage(image_urls.get(i - a).get("url"), v, options);

                    v.setTag(image_urls.get(i - a).get("id"));
                    v.setOnClickListener(new OnClickListener() {

                        @Override
                        public void onClick(View arg0) {
                            Intent i = new Intent(MainActivity.this, ApkInfo.class);
                            i.putExtra("_id", Long.parseLong((String) arg0.getTag()));
                            i.putExtra("top", false);
                            i.putExtra("category", Category.EDITORSCHOICE.ordinal());
                            startActivity(i);
                        }
                    });
                    // v.setOnClickListener(featuredListener);
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }

        }
    });
}

From source file:com.twitter.distributedlog.service.balancer.ClusterBalancer.java

void moveStreams(List<Host> hosts, AtomicInteger hostIdxMoveFrom, int moveFromLowWaterMark,
        AtomicInteger hostIdxMoveTo, int moveToHighWaterMark, Optional<RateLimiter> rateLimiter) {
    if (hostIdxMoveFrom.get() < 0 || hostIdxMoveFrom.get() >= hosts.size() || hostIdxMoveTo.get() < 0
            || hostIdxMoveTo.get() >= hosts.size() || hostIdxMoveFrom.get() >= hostIdxMoveTo.get()) {
        return;/* w  w w . j a va 2 s . c  o  m*/
    }

    if (logger.isDebugEnabled()) {
        logger.debug(
                "Moving streams : hosts = {}, from = {}, to = {} : from_low_water_mark = {}, to_high_water_mark = {}",
                new Object[] { hosts, hostIdxMoveFrom.get(), hostIdxMoveTo.get(), moveFromLowWaterMark,
                        moveToHighWaterMark });
    }

    Host hostMoveFrom = hosts.get(hostIdxMoveFrom.get());
    int numStreamsOnFromHost = hostMoveFrom.streams.size();
    if (numStreamsOnFromHost <= moveFromLowWaterMark) {
        // do nothing
        return;
    }

    int numStreamsToMove = numStreamsOnFromHost - moveFromLowWaterMark;
    LinkedList<String> streamsToMove = new LinkedList<String>(hostMoveFrom.streams);
    Collections.shuffle(streamsToMove);

    if (logger.isDebugEnabled()) {
        logger.debug("Try to move {} streams from host {} : streams = {}",
                new Object[] { numStreamsToMove, hostMoveFrom.address, streamsToMove });
    }

    while (numStreamsToMove-- > 0 && !streamsToMove.isEmpty()) {
        if (rateLimiter.isPresent()) {
            rateLimiter.get().acquire();
        }

        // pick a host to move
        Host hostMoveTo = hosts.get(hostIdxMoveTo.get());
        while (hostMoveTo.streams.size() >= moveToHighWaterMark) {
            int hostIdx = hostIdxMoveTo.decrementAndGet();
            logger.info("move to host : {}, from {}", hostIdx, hostIdxMoveFrom.get());
            if (hostIdx <= hostIdxMoveFrom.get()) {
                return;
            } else {
                hostMoveTo = hosts.get(hostIdx);
                if (logger.isDebugEnabled()) {
                    logger.debug("Target host to move moved to host {} @ {}", hostIdx, hostMoveTo);
                }
            }
        }

        // pick a stream
        String stream = streamsToMove.remove();

        // move the stream
        if (moveStream(stream, hostMoveFrom, hostMoveTo)) {
            hostMoveFrom.streams.remove(stream);
            hostMoveTo.streams.add(stream);
        }
    }

}

From source file:clummy.classes.DataHandlingClass.java

/**
 * to permutate the list into unique combination of list
 * @param filesToRead/* w w w . j av  a  2  s  .  com*/
 * @return 
 */
public List<String> getPermutationOfNames(String filesToRead) {
    List<String> listNames = new ArrayList<>();
    ICombinatoricsVector<String> initialVector = Factory.createVector(readFile(filesToRead));
    // Create a simple combination generator to generate 3-combinations of the initial vector
    Generator<String> gen = Factory.createSimpleCombinationGenerator(initialVector, 2);

    // Print all possible combinations in vector
    for (ICombinatoricsVector<String> combination : gen) {
        //transfer vector to list and trim unessacry characters
        listNames.add(
                combination.getVector().toString().replace(",", "").replace("[", "").replace("]", "").trim());

    }
    //shuffle the list
    Collections.shuffle(listNames);
    Collections.shuffle(listNames);
    totalListFromName = listNames.size();
    System.out.println(listNames);
    return listNames;
}

From source file:edu.ucla.cs.scai.swim.qa.ontology.dbpedia.tipicality.Test.java

private static ArrayList<HashSet<String>> extractEntities(File csvData, int nOfAttributes) throws IOException {
    CSVParser parser = CSVParser.parse(csvData, Charset.defaultCharset(), CSVFormat.RFC4180);
    int r = 0;//w  w w  .jav  a  2 s .  com
    ArrayList<Integer> attributePositions = new ArrayList<>();
    ArrayList<String> attributeNames = new ArrayList<>();
    ArrayList<HashSet<String>> res = new ArrayList<>();
    for (CSVRecord csvRecord : parser) {
        if (r == 0) {
            Iterator<String> it = csvRecord.iterator();
            it.next(); //skip URI
            if (!it.hasNext()) { //it is an empty file
                return res;
            }
            it.next(); //skip rdf-schema#label
            it.next(); //skip rdf-schema#comment
            int c = 2;
            for (; it.hasNext();) {
                c++;
                String attr = it.next();
                if (!attr.endsWith("_label")) {
                    attributePositions.add(c);
                }
            }
        } else if (r == 1) {
            Iterator<String> it = csvRecord.iterator();
            it.next(); //skip uri
            it.next(); //skip rdf-schema#label
            it.next(); //skip rdf-schema#comment
            int c = 2;
            int i = 0;
            while (i < attributePositions.size()) {
                c++;
                String attr = it.next();
                if (attributePositions.get(i) == c) {
                    if (!stopAttributes.contains(attr)) {
                        attributes.add(attr);
                    }
                    attributeNames.add(attr);
                    i++;
                }
            }
        } else if (r > 3) {
            ArrayList<String> attributesOfThisEntity = new ArrayList<>();
            Iterator<String> it = csvRecord.iterator();
            String uri = it.next();
            it.next(); //skip rdf-schema#label
            it.next(); //skip rdf-schema#comment
            int c = 2;
            int i = 0;
            while (i < attributePositions.size()) {
                c++;
                String val = it.next();
                if (attributePositions.get(i) == c) {
                    if (!val.equalsIgnoreCase("null")) {
                        String attribute = attributeNames.get(i);
                        if (!stopAttributes.contains(attribute)) {
                            attributesOfThisEntity.add(attribute);
                        }
                    }
                    i++;
                }
            }
            Collections.shuffle(attributesOfThisEntity);
            HashSet<String> s = new HashSet<>();
            for (int k = 0; k < Math.min(nOfAttributes, attributesOfThisEntity.size()); k++) {
                s.add(attributesOfThisEntity.get(k));
            }
            res.add(s);
        }
        r++;
    }
    return res;
}

From source file:com.caved_in.commons.utilities.StringUtil.java

/**
 * Scramble text; What else is there?// w w w.ja  v a2 s.  c  o  m
 *
 * @param text
 * @return
 */
public static String scrambleText(String text) {
    StringBuilder Scrambled = new StringBuilder();
    if (text.contains(" ")) {
        String[] Words = text.split(" ");
        for (String word : Words) {
            ArrayList<Character> chars = new ArrayList<>(word.length());
            for (char c : word.toCharArray()) {
                chars.add(c);
            }
            Collections.shuffle(chars);
            char[] shuffled = new char[chars.size()];
            for (int i = 0; i < shuffled.length; i++) {
                shuffled[i] = chars.get(i);
            }
            Scrambled.append(" ").append(shuffled);
        }
        return Scrambled.toString();
    } else {
        ArrayList<Character> chars = new ArrayList<>(text.length());
        for (char c : text.toCharArray()) {
            chars.add(c);
        }
        Collections.shuffle(chars);
        char[] shuffled = new char[chars.size()];
        for (int i = 0; i < shuffled.length; i++) {
            shuffled[i] = chars.get(i);
        }
        return new String(shuffled);
    }
}

From source file:br.com.autonomiccs.autonomic.plugin.common.services.AutonomiccsSystemVmDeploymentService.java

/**
 * This method tries to find a suitable host to deploy an Autonomiccs system VM.
 * The process is the following:/*w ww. j av a2  s  .  co m*/
 * <ul>
 *   <li>We load all hosts of the given cluster, we also shuffle the host list;
 *   <li>after that, we go over the host list and check if it can host the system VM {@link #canHostSupportVm(ServiceOfferingVO, HostResources)}
 *   <li>if the host has resources to support the system VM, we check if its hypervisor type has a system VM template registered for it, if so we use it as the host to deploy the system VM
 * </ul>
 * @param c cluster to look for a host to deploy a system VM
 * @param excludeHosts hosts to exclude from the search
 * @return {@link HostVO} to deploy a system VM, it may return null if no suitable hosts have been found
 */
private HostVO searchForAnotherRandomHostInTheClusterToStartSystemVmExcludingHosts(ClusterVO c,
        List<HostVO> excludeHosts) {
    List<HostVO> allHostsInCluster = hostService.listAllHostsInCluster(c);
    allHostsInCluster.removeAll(excludeHosts);
    Collections.shuffle(allHostsInCluster);
    for (HostVO h : allHostsInCluster) {
        if (canDeployAutonomiccsSystemVmOnHost(h)) {
            return h;
        }
    }
    logger.info(String.format(
            "Could not find any suitable hosts to deploy the system VM into cluster [clusterId=%d, clusterName=%s]",
            c.getId(), c.getName()));
    return null;
}

From source file:de.Keyle.MyPet.entity.MyPet.java

public boolean autoAssignSkilltree() {
    if (skillTree == null && this.petOwner.isOnline()) {
        if (Configuration.Skilltree.AUTOMATIC_SKILLTREE_ASSIGNMENT) {
            if (SkillTreeMobType.getSkillTreeNames(this.getPetType()).size() > 0) {
                List<SkillTree> skilltrees = SkillTreeMobType.getSkillTrees(this.getPetType());
                if (Configuration.Skilltree.RANDOM_SKILLTREE_ASSIGNMENT) {
                    Collections.shuffle(skilltrees);
                }/*from  w w w  .j a  v a2 s. com*/
                for (SkillTree skillTree : skilltrees) {
                    if (Permissions.hasLegacy(this.petOwner.getPlayer(), "MyPet.skilltree.",
                            skillTree.getPermission())) {
                        return setSkilltree(skillTree);
                    }
                }
            }
        } else {
            for (SkillTree skillTree : SkillTreeMobType.getSkillTrees(this.getPetType())) {
                if (Permissions.hasLegacy(this.petOwner.getPlayer(), "MyPet.skilltree.",
                        skillTree.getPermission())) {
                    getOwner().sendMessage(Util.formatText(
                            Translation.getString("Message.Skilltree.SelectionPrompt", getOwner()),
                            getPetName()));
                    break;
                }
            }
            return false;
        }
    }
    return true;
}