Example usage for java.util Collections shuffle

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:net.nelz.simplesm.test.ReadThroughMultiCacheTest.java

@Test
public void test() {
    final Long rawNow = System.currentTimeMillis();
    final Long now = (rawNow / 1000) * 10000;
    final List<Long> subset = new ArrayList<Long>();
    final List<Long> superset = new ArrayList<Long>();
    final List<Long> jumbleset = new ArrayList<Long>();

    for (Long ix = 1 + now; ix < 35 + now; ix++) {
        if (ix % 3 == 0) {
            subset.add(ix);/*w ww  .j av  a 2  s .  com*/
        }
        superset.add(ix);
        jumbleset.add(ix);
    }
    Collections.shuffle(jumbleset);

    final TestSvc test = (TestSvc) context.getBean("testSvc");

    // Get all the results for the subset ids.
    // Ensure the ids line up with the results, and have the same timestamp.
    final List<String> subsetResult = test.getTimestampValues(subset);
    assertEquals(subset.size(), subsetResult.size());
    String subsetTime = null;
    for (int ix = 0; ix < subset.size(); ix++) {
        final Long key = subset.get(ix);
        final String value = subsetResult.get(ix);
        System.out.println("Subset: " + value);
        final String[] parts = value.split("-X-");
        if (subsetTime == null) {
            subsetTime = parts[0];
        } else {
            assertEquals(subsetTime, parts[0]);
        }
        assertEquals(key.toString(), parts[1]);
    }

    // Now call the full list.
    // Ensure id's line up, and that results from ids that got passed in the subset
    // have the older time stamp.
    final List<String> supersetResult = test.getTimestampValues(superset);
    assertEquals(superset.size(), supersetResult.size());
    String supersetTime = null;
    for (int ix = 0; ix < superset.size(); ix++) {
        final Long key = superset.get(ix);
        final String value = supersetResult.get(ix);
        System.out.println("Superset: " + value);
        final String[] parts = value.split("-X-");
        final boolean inSubset = subset.contains(key);
        if (!inSubset && supersetTime == null) {
            supersetTime = parts[0];
        } else if (inSubset) {
            assertEquals(subsetTime, parts[0]);
        } else {
            assertEquals(supersetTime, parts[0]);
        }
        assertEquals(key.toString(), parts[1]);
    }

    // Now call for the results again, but with a randomized
    // set of keys.  This is to ensure the proper values line up with
    // the given keys.
    final List<String> jumblesetResult = test.getTimestampValues(jumbleset);
    assertEquals(jumbleset.size(), jumblesetResult.size());
    for (int ix = 0; ix < jumbleset.size(); ix++) {
        final Long key = jumbleset.get(ix);
        final String value = jumblesetResult.get(ix);
        System.out.println("Jumbleset: " + value);
        final String[] parts = value.split("-X-");
        final boolean inSubset = subset.contains(key);
        if (inSubset) {
            assertEquals(subsetTime, parts[0]);
        } else {
            assertEquals(supersetTime, parts[0]);
        }
        assertEquals(key.toString(), parts[1]);
    }

}

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From source file:com.rabbitmq.jms.sample.StockQuoter.java

@Scheduled(fixedRate = 5000L) // every 5 seconds
public void publishQuote() {

    // Pick a random stock symbol
    Collections.shuffle(stocks);
    String symbol = stocks.get(0);

    // Toss a coin and decide if the price goes...
    if (RandomUtils.nextBoolean()) {
        // ...up by a random 0-10%
        lastPrice.put(symbol, new Double(
                Math.round(lastPrice.get(symbol) * (1 + RandomUtils.nextInt(10) / 100.0) * 100) / 100));
    } else {//from   w w w  .  j  av  a  2s.c o m
        // ...or down by a similar random amount
        lastPrice.put(symbol, new Double(
                Math.round(lastPrice.get(symbol) * (1 - RandomUtils.nextInt(10) / 100.0) * 100) / 100));
    }

    // Log new price locally
    log.info("Quote..." + symbol + " is now " + lastPrice.get(symbol));

    // Coerce a javax.jms.MessageCreator
    MessageCreator messageCreator = (Session session) -> {
        return session.createObjectMessage("Quote..." + symbol + " is now " + lastPrice.get(symbol));
    };

    // And publish to RabbitMQ using Spring's JmsTemplate
    jmsTemplate.send("rabbit-trader-channel", messageCreator);
}

---

From source file:com.cloudera.oryx.ml.param.GridSearch.java

/**
 * @param ranges ranges of hyperparameters to try, one per hyperparameters
 * @param howMany how many combinations of hyperparameters to return
 * @return combinations of concrete hyperparameter values. For example, for 5 parameters each
 *  with 3 values to try, the total number of combinations returned could be up to pow(3,5)
 *  or 243. The number could be less if the ranges do not actually have that many distinct
 *  values. If {@code howMany} is smaller than the total number of combinations, a random
 *  subset of all combinations are returned. The order is shuffled randomly. If no parameters
 *  are specified or {@code perParam} is 0, a single empty combination is returned.
 *///from   ww w  . ja v  a  2 s.  co m
static List<List<?>> chooseHyperParameterCombos(List<HyperParamValues<?>> ranges, int howMany) {
    // Put some reasonable upper limit on the number of combos
    Preconditions.checkArgument(howMany > 0 && howMany <= MAX_COMBOS);

    int numParams = ranges.size();
    int perParam = chooseValuesPerHyperParam(ranges, howMany);
    if (numParams == 0 || perParam == 0) {
        return Collections.singletonList(Collections.emptyList());
    }

    int howManyCombos = 1;
    List<List<?>> paramRanges = new ArrayList<>(numParams);
    for (HyperParamValues<?> range : ranges) {
        List<?> values = range.getTrialValues(perParam);
        paramRanges.add(values);
        howManyCombos *= values.size();
    }

    List<List<?>> allCombinations = new ArrayList<>(howManyCombos);
    for (int combo = 0; combo < howManyCombos; combo++) {
        List<Object> combination = new ArrayList<>(numParams);
        for (int param = 0; param < numParams; param++) {
            int whichValueToTry = combo;
            for (int i = 0; i < param; i++) {
                whichValueToTry /= paramRanges.get(i).size();
            }
            whichValueToTry %= paramRanges.get(param).size();
            combination.add(paramRanges.get(param).get(whichValueToTry));
        }
        allCombinations.add(combination);
    }

    if (howMany >= howManyCombos) {
        Collections.shuffle(allCombinations);
        return allCombinations;
    }
    RandomDataGenerator rdg = new RandomDataGenerator(RandomManager.getRandom());
    int[] indices = rdg.nextPermutation(howManyCombos, howMany);
    List<List<?>> result = new ArrayList<>(indices.length);
    for (int i = 0; i < indices.length; i++) {
        result.add(allCombinations.get(i));
    }
    Collections.shuffle(result);
    return result;
}

---

From source file:com.joyent.manta.client.MantaObjectDepthComparatorTest.java

public void verifyOrderingWithMoreSubdirectoriesDataSet() {
    List<MantaObject> objects = new ArrayList<>();
    List<MantaObject> dirs = dirObjects(29);

    for (MantaObject dir : dirs) {
        objects.add(dir);//from   ww  w.  j  a v  a2  s.  c om
        objects.addAll(fileObjects(dir, 24));

        MantaObject subdir = mockDirectory(dir.getPath() + MantaClient.SEPARATOR + "subdir");
        objects.add(subdir);
        objects.addAll(fileObjects(subdir, 3));
    }

    Collections.shuffle(objects);

    objects.sort(MantaObjectDepthComparator.INSTANCE);

    assertOrdering(objects);
}

---

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

CountBasedStreamChooser(Map<SocketAddress, Set<String>> streams) {
    Preconditions.checkArgument(streams.size() > 0, "Only support no-empty streams distribution");
    streamsDistribution = new ArrayList<Pair<SocketAddress, LinkedList<String>>>(streams.size());
    for (Map.Entry<SocketAddress, Set<String>> entry : streams.entrySet()) {
        LinkedList<String> randomizedStreams = new LinkedList<String>(entry.getValue());
        Collections.shuffle(randomizedStreams);
        streamsDistribution.add(Pair.of(entry.getKey(), randomizedStreams));
    }/*  w w w  .  j  a  va 2 s  .  c  o  m*/
    // sort the hosts by the number of streams in descending order
    Collections.sort(streamsDistribution, this);
    pivot = 0;
    pivotCount = streamsDistribution.get(0).getValue().size();
    findNextPivot();
    next = 0;
}

---

From source file:com.github.fge.uritemplate.SpecExamplesBySectionTest.java

@DataProvider
public Iterator<Object[]> getData() {
    final List<Object[]> list = Lists.newArrayList();

    VariableMapBuilder builder;/*from ww  w. ja  va2 s . com*/
    Iterator<Map.Entry<String, JsonNode>> iterator;
    Map.Entry<String, JsonNode> entry;

    for (final JsonNode node : data) { // Cycle through values
        builder = VariableMap.newBuilder();
        iterator = node.get("variables").fields();
        while (iterator.hasNext()) {
            entry = iterator.next();
            if (entry.getValue().isNull())
                continue;
            builder.addValue(entry.getKey(), Util.fromJson(entry.getValue()));
        }
        for (final JsonNode n : node.get("testcases"))
            list.add(new Object[] { n.get(0).textValue(), builder.freeze(), n.get(1) });
    }

    Collections.shuffle(list);

    return list.iterator();
}

---

From source file:com.serphacker.serposcope.di.CaptchaSolverFactoryImpl.java

@Override
public CaptchaSolver get(Config config) {
    if (config == null) {
        return null;
    }/*from w  ww .j ava 2s.  c  om*/

    List<CaptchaSolver> solvers = new ArrayList<>();

    if (!StringUtils.isEmpty(config.getDbcUser()) && !StringUtils.isEmpty(config.getDbcPass())) {
        DeathByCaptchaSolver solver = new DeathByCaptchaSolver(config.getDbcUser(), config.getDbcPass());
        if (init(solver)) {
            solvers.add(solver);
        }
    }

    if (!StringUtils.isEmpty(config.getDecaptcherUser()) && !StringUtils.isEmpty(config.getDecaptcherPass())) {
        DecaptcherSolver solver = new DecaptcherSolver(config.getDecaptcherUser(), config.getDecaptcherPass());
        if (init(solver)) {
            solvers.add(solver);
        }
    }

    if (!StringUtils.isEmpty(config.getAnticaptchaKey())) {
        AntiCaptchaSolver solver = new AntiCaptchaSolver(config.getAnticaptchaKey());
        if (init(solver)) {
            solvers.add(solver);
        }
    }

    if (solvers.isEmpty()) {
        return null;
    }

    Collections.shuffle(solvers);
    return new FailoverCaptchaSolver(solvers);
}

---

From source file:com.adaptris.core.fs.enhanced.FileSorterCase.java

protected List<File> createFiles(int count, String prefix, String suffix, long pause) throws Exception {
    List<Integer> nums = new ArrayList<Integer>();
    List<File> result = new ArrayList<File>();
    for (int i = 1; i <= count; i++) {
        nums.add(Integer.valueOf(i));
    }//from  ww w  . j av  a  2  s.  co m
    Collections.shuffle(nums);
    for (Integer i : nums) {
        File f = new File(baseDir, String.format("%1$s-%2$03d%3$s", prefix, i, suffix));
        // Write it in gradients of 512bytes
        ensureSize(512 * i, f);
        result.add(f);
        if (pause > 0) {
            Thread.sleep(pause);
        }
    }
    log("createFiles", result);
    return result;
}

---

From source file:com.streamreduce.util.SecurityUtil.java

public static String generateRandomString(int n) {

    Random rd = new Random();

    char lowerChars[] = "abcdefghijklmnopqrstuvwxyz".toCharArray();
    char upperChars[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZ".toCharArray();
    char numbers[] = "0123456789".toCharArray();
    //char specialChars[] = "~!@#$%^&*()-_=+[{]}|;:<>/?".toCharArray();
    char specialChars[] = "!$-_+".toCharArray(); // limited subset

    List<Character> pwdLst = new ArrayList<>();
    for (int g = 0; g <= n; g++) {
        for (int z = 0; z < 1; z++) {
            if (g == 0) {
                pwdLst.add(numbers[rd.nextInt(10)]); // must match char array length(s) above
            } else if (g == 1) {
                pwdLst.add(lowerChars[rd.nextInt(26)]);
            } else if (g == 2) {
                pwdLst.add(upperChars[rd.nextInt(26)]);
            } else if (g == 3) {
                pwdLst.add(specialChars[rd.nextInt(5)]);
            }//from   w  w w.ja  va  2  s.  co m
        }
        if (pwdLst.size() == n) {
            break;
        }
        if (g + 1 == 4) {
            g = (int) (Math.random() * 5);

        }
    }
    StringBuilder password = new StringBuilder();
    Collections.shuffle(pwdLst);
    for (Character aPwdLst : pwdLst) {
        password.append(aPwdLst);
    }
    return password.toString();
}

---

From source file:org.flite.cach3.test.l2.L2ReadThroughSingleTest.java

@Test
public void test() {
    final TestSvc test = (TestSvc) context.getBean("testSvc");

    final String g1 = RandomStringUtils.randomAlphabetic(4) + "-";
    final List<Long> ids = new ArrayList<Long>();
    final long base = System.currentTimeMillis() - 200000;
    for (int ix = 0; ix < 10; ix++) {
        final long id = base + ix;
        ids.add(id);//from ww  w  .  ja  v  a2s .  c o m
        assertTrue(test.getL2SingleDelta(id, g1).startsWith(g1));
    }

    final String g2 = RandomStringUtils.randomAlphabetic(6) + "-";
    final List<Long> addls = new ArrayList<Long>();
    addls.addAll(ids);
    for (int ix = 0; ix < 10; ix++) {
        addls.add(1000L + ix);
    }

    Collections.shuffle(addls);
    final List<String> results = test.getL2MultiAlpha(addls, g2);
    for (int ix = 0; ix < addls.size(); ix++) {
        final Long key = addls.get(ix);
        final String result = results.get(ix);
        System.out.println(result);
        assertTrue(StringUtils.contains(result, key.toString()));
        assertTrue(result.startsWith(ids.contains(key) ? g1 : g2));
    }

}

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