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:com.netflix.iep.dynprop.RemoteConfigurationSource.java

private List<String> getHostsForVip(String vip, boolean useIp) {
    List<InstanceInfo> instances = client.getInstancesByVipAddress(vip, false);
    List<String> filtered = new ArrayList<>(instances.size());
    for (InstanceInfo info : instances) {
        if (info.getStatus() == InstanceInfo.InstanceStatus.UP) {
            String host = useIp ? info.getIPAddr() : info.getHostName();
            filtered.add(host + ":" + info.getPort());
        }//from w  ww  .j a  v a 2 s.c  o  m
    }
    Collections.shuffle(filtered);
    return filtered;
}

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From source file:net.sf.gazpachoquest.questionnaire.resolver.SectionBySectionResolver.java

@Override
protected List<SectionBreadcrumb> makeBreadcrumbs(QuestionnaireDefinition questionnaireDefinition,
        Questionnaire questionnaire) {/*from   www. j  a v  a  2 s.co m*/
    List<SectionBreadcrumb> breadcrumbs = new ArrayList<>();
    SectionBreadcrumb breadcrumb = null;
    Integer questionnaireDefinitionId = questionnaireDefinition.getId();
    RandomizationStrategy randomizationStrategy = questionnaireDefinition.getRandomizationStrategy();
    if (RandomizationStrategy.SECTIONS_RANDOMIZATION.equals(randomizationStrategy)) {
        List<Section> sections = sectionService.findByExample(
                Section.with()
                        .questionnaireDefinition(
                                QuestionnaireDefinition.with().id(questionnaireDefinitionId).build())
                        .build(),
                new SearchParameters());
        Collections.shuffle(sections);
        for (Section section : sections) {
            breadcrumb = SectionBreadcrumb.with().questionnaire(questionnaire).section(section)
                    .last(Boolean.FALSE).renderingMode(RenderingMode.SECTION_BY_SECTION).build();
            breadcrumbs.add(breadcrumb);
        }
        populateQuestionsBreadcrumbs(breadcrumbs, QUESTION_NUMBER_START_COUNTER);
    } else if (RandomizationStrategy.QUESTIONS_RANDOMIZATION.equals(randomizationStrategy)) {
        List<Question> questions = questionnaireDefinitionService.getQuestions(questionnaireDefinitionId);
        Collections.shuffle(questions);
        Integer questionPerPage = questionnaireDefinition.getQuestionsPerPage();
        int questionIdx = 0;
        Integer questionNumberCounter = QUESTION_NUMBER_START_COUNTER;
        for (Question question : questions) {
            if (questionIdx % questionPerPage == 0) {
                breadcrumb = SectionBreadcrumb.with().questionnaire(questionnaire).last(Boolean.FALSE)
                        .renderingMode(RenderingMode.SECTION_BY_SECTION).build();
                breadcrumbs.add(breadcrumb);
            }
            breadcrumb.addBreadcrumb(QuestionBreadcrumb.with().question(question).last(Boolean.FALSE)
                    .questionNumber(questionNumberCounter++).build());
            questionIdx++;
        }

    } else {
        Section section = sectionService.findOneByPositionInQuestionnaireDefinition(questionnaireDefinitionId,
                INITIAL_POSITION);
        breadcrumb = SectionBreadcrumb.with().questionnaire(questionnaire).section(section)
                .renderingMode(RenderingMode.SECTION_BY_SECTION).build();
        breadcrumbs.add(breadcrumb);
        populateQuestionsBreadcrumbs(breadcrumbs, QUESTION_NUMBER_START_COUNTER);
    }
    breadcrumbs.get(0).setLast(Boolean.TRUE);
    return breadcrumbs;
}

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From source file:de.whs.poodle.controllers.student.StudentMcWorksheetController.java

@RequestMapping
@PreAuthorize("@studentSecurity.hasAccessToMcWorksheet(authentication.name, #mcWorksheetId)")
public String get(@ModelAttribute Student student, @PathVariable int mcWorksheetId, Model model) {
    // get the worksheet
    McWorksheet mcWorksheet = mcWorksheetRepo.getByMcWorksheetId(mcWorksheetId);
    if (mcWorksheet == null)
        throw new NotFoundException();

    // get the question that the student has to answer next
    Integer currentQuestionId = mcWorksheetRepo.getCurrentQuestionIdForStudentAndWorksheet(student.getId(),
            mcWorksheetId);/*from w  w  w  .j  a  v a2  s.  c  o m*/

    // no next question, this must mean that the worksheets has been completed, show the results
    if (currentQuestionId == null) {
        return "redirect:/student/multipleChoiceResults/{mcWorksheetId}";
    }

    // get the question
    McQuestionOnWorksheet currentQuestion = mcWorksheet.getQuestions().stream()
            .filter(q -> q.getId() == currentQuestionId).findFirst().orElse(null);

    if (currentQuestion == null)
        throw new RuntimeException(
                "the current question for this worksheet is not in the worksheet, this shouldn't be possible...");

    // shuffle the answers
    Collections.shuffle(currentQuestion.getQuestion().getAnswers());

    // make sure to set a timestamp for "seen_at"
    mcWorksheetRepo.prepareMcStatistics(student.getId(), mcWorksheet.getCourseTerm().getId(),
            currentQuestion.getId());

    model.addAttribute("worksheet", mcWorksheet);
    model.addAttribute("questionOnWs", currentQuestion);

    return "student/answerMcQuestion";
}

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From source file:co.mafiagame.engine.command.internalcommand.StartGameCommand.java

private void assignRoles(List<Player> players, GameState gameState) {
    Collections.shuffle(players);
    int assigned = 0;
    for (int i = 0; i < gameState.getCitizenNum(); i++)
        players.get(assigned + i).setRole(Role.CITIZEN);
    assigned += gameState.getCitizenNum();
    for (int i = 0; i < gameState.getMafiaNum(); i++)
        players.get(assigned + i).setRole(Role.MAFIA);
    assigned += gameState.getMafiaNum();
    for (int i = 0; i < gameState.getDetectiveNum(); i++)
        players.get(assigned + i).setRole(Role.DETECTIVE);
    assigned += gameState.getDetectiveNum();
    for (int i = 0; i < gameState.getDoctorNum(); i++)
        players.get(assigned + i).setRole(Role.DOCTOR);
    Collections.shuffle(players);
}

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From source file:com.google.code.ssm.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  w w  .j  a  v a  2  s.  c o  m*/
        }
        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.linkedin.pinot.tools.query.comparison.StarTreeQueryGenerator.java

/**
 * Generate the aggregation section of the query, returns at least one aggregation.
 * @return//from ww  w .ja va  2s.co  m
 */
private String generateAggregations() {
    int numAggregations = _random.nextInt(_metricColumns.size() + 1);
    numAggregations = Math.max(numAggregations, 1);
    List<String> aggregations = new ArrayList<>(numAggregations);

    Collections.shuffle(_metricColumns);
    for (int i = 0; i < numAggregations; i++) {
        aggregations.add(generateAggregation(_metricColumns.get(i)));
    }

    return StringUtils.join(aggregations, ", ");
}

---

From source file:net.myrrix.batch.common.iterator.sequencefile.SequenceFileDirIterator.java

/**
 * Constructor that uses either {@link FileSystem#listStatus(Path)} or
 * {@link FileSystem#globStatus(Path)} to obtain list of files to iterate over
 * (depending on pathType parameter)./*w  w w. j a va2 s. co  m*/
 */
public SequenceFileDirIterator(Path path, PathType pathType, PathFilter filter, Comparator<FileStatus> ordering,
        final boolean reuseKeyValueInstances, final Configuration conf) throws IOException {

    FileStatus[] statuses;
    FileSystem fs = path.getFileSystem(conf);
    if (filter == null) {
        statuses = pathType == PathType.GLOB ? fs.globStatus(path) : fs.listStatus(path);
    } else {
        statuses = pathType == PathType.GLOB ? fs.globStatus(path, filter) : fs.listStatus(path, filter);
    }

    if (statuses == null) {
        statuses = NO_STATUSES;
    } else {
        if (ordering == null) {
            // If order does not matter, use a random order
            Collections.shuffle(Arrays.asList(statuses));
        } else {
            Arrays.sort(statuses, ordering);
        }
    }

    closer = Closer.create();

    Iterator<Iterator<Pair<K, V>>> fsIterators = Iterators.transform(Iterators.forArray(statuses),
            new Function<FileStatus, Iterator<Pair<K, V>>>() {
                @Override
                public Iterator<Pair<K, V>> apply(FileStatus from) {
                    try {
                        SequenceFileIterator<K, V> iterator = new SequenceFileIterator<K, V>(from.getPath(),
                                reuseKeyValueInstances, conf);
                        closer.register(iterator);
                        return iterator;
                    } catch (IOException ioe) {
                        throw new IllegalStateException(from.getPath().toString(), ioe);
                    }
                }
            });

    delegate = Iterators.concat(fsIterators);
}

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From source file:de.unisb.cs.st.javalanche.rhino.coverage.CoberturaParser.java

private static void getCoveragePrioritization() {
    File[] files = getXmlFiles();
    Map<CoverageData, String> map = parseFiles(files);
    FailureMatrix fm = FailureMatrix/*  w ww.j av  a  2s .c  o m*/
            .parseFile(new File("/scratch/schuler/subjects/ibugs_rhino-0.1/failureMatrix.csv"));
    ArrayList<CoverageData> coverageDataList = new ArrayList<CoverageData>(map.keySet());
    List<List<PriorizationResult>> averageList = new ArrayList<List<PriorizationResult>>();
    final int SHUFFLES = 1000;
    for (int i = 1; i < SHUFFLES; i++) {
        if (i % 100 == 0) {
            System.out.println("Computing result " + i);
        }
        Collections.shuffle(coverageDataList);
        List<PriorizationResult> prioritizedTotal = CoverageData.prioritizeTotal(coverageDataList);
        averageList.add(new ArrayList<PriorizationResult>(prioritizedTotal));
        if (i == 1) {
            double[] averageData = generateAverageData(fm, averageList);
            writeRData(averageData, "total-coverage");
        }
    }
    double[] avarageData = generateAverageData(fm, averageList);
    writeRData(avarageData, "total-coverage-average");
    averageList = new ArrayList<List<PriorizationResult>>();
    for (int i = 1; i < SHUFFLES; i++) {
        if (i % 100 == 0) {
            System.out.println("Computing result " + i);
        }
        Collections.shuffle(coverageDataList);
        List<PriorizationResult> prioritizedAdditional = CoverageData.prioritizeAdditional(coverageDataList);
        averageList.add(new ArrayList<PriorizationResult>(prioritizedAdditional));
        if (i == 1) {
            double[] averageData = generateAverageData(fm, averageList);
            writeRData(averageData, "additional-coverage");
        }

    }
    double[] avarageDataAdd = generateAverageData(fm, averageList);
    writeRData(avarageDataAdd, "additional-coverage-average");
}

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From source file:c5db.tablet.tabletCreationBehaviors.RootTabletLeaderBehavior.java

private List<Long> shuffleListAndReturnMetaRegionPeers(final List<Long> peers) {
    Collections.shuffle(new ArrayList<>(peers));
    return peers.subList(0, (int) numberOfMetaPeers);
}

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From source file:com.google.android.apps.santatracker.games.cityquiz.CityQuizUtil.java

private static List<City> getCities(Context context) {
    List<City> cities = new ArrayList<>();
    JSONArray jCities = getCitiesFromFile(context);
    for (int i = 0; jCities != null && i < jCities.length(); i++) {
        try {//from  ww  w.ja  va  2s. c om
            JSONObject jCity = jCities.getJSONObject(i);
            double lat = jCity.getDouble("lat");
            double lng = jCity.getDouble("lng");
            String cityResourceName = jCity.getString("name");
            int cityNameResourceId = context.getResources().getIdentifier(cityResourceName, "string",
                    context.getPackageName());
            String cityName;
            // Check if city name string resource is found.
            if (cityNameResourceId != 0) {
                // Use string resource for city name.
                cityName = context.getResources().getString(cityNameResourceId);
            } else {
                // Use default English city name.
                cityName = jCity.getString("default_name");
            }
            String imageUrl = jCity.getString("image_name");
            String imageAuthor = jCity.getString("image_author");
            City city = new City(lat, lng, imageUrl, imageAuthor, cityName);
            cities.add(city);
        } catch (JSONException e) {
            Log.e(TAG, "Unable to get city from json, " + e);
        }
    }

    // Check if there are enough cities to set fake ones.
    if (cities.size() > 3) {
        // Set fake locations for each city.
        for (int i = 0; i < cities.size(); i++) {
            City city = cities.get(i);
            List<City> tempCities = new ArrayList<>(cities);
            // Sort tempCities in order of closest to the current city.
            Collections.sort(tempCities, new CityLocationComparator(city));

            // Get the closest three cities, excluding the current city.
            List<City> closestCities = tempCities.subList(1, 4);
            Collections.shuffle(closestCities);

            // Choose the first two of the three cities from the closestCities list.
            city.setIncorrectLoaciton(City.FIRST_FAKE_INDEX, closestCities.get(0).getCorrectLocation());
            city.setIncorrectLoaciton(City.SECOND_FAKE_INDEX, closestCities.get(1).getCorrectLocation());
        }
    }

    return cities;
}

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