Example usage for java.util Optional ofNullable

Introduction

In this page you can find the example usage for java.util Optional ofNullable.

Prototype

@SuppressWarnings("unchecked")
public static <T> Optional<T> ofNullable(T value)

Source Link

Document

Returns an Optional describing the given value, if non- null , otherwise returns an empty Optional .

Usage

From source file:Main.java

/**
 * Convert a sequence of elements to the list.
 *
 * @param <I> Type of objects for input collection
 * @param <O> Type of objects for output collection
 * @param iterable The sequence of elements to convert. If the input
 *     sequence is empty, then the resulting collection will be empty
 * @param transformer The conversion function. If the transfer function is
 *     not set, the resulting collection will be empty
 * @return Reformed collection of input elements
 *///from   ww  w  . ja v  a 2  s . com
public static <I, O> List<O> transformWithoutNull(final Iterable<I> iterable,
        final Function<I, O> transformer) {
    return StreamSupport
            .stream(Optional.ofNullable(iterable).orElse(Collections.<I>emptySet()).spliterator(), false)
            .map(Optional.ofNullable(transformer).orElse(i -> null)).filter(Objects::nonNull)
            .collect(Collectors.toList());
}

From source file:ru.mystamps.web.support.spring.security.SecurityContextUtils.java

/**
 * @author Sergey Chechenev// w  w  w . j a  va  2s .c  o m
 * @author Slava Semushin
 */
public static Integer getUserId() {
    return Optional.ofNullable(SecurityContextHolder.getContext().getAuthentication())
            .map(Authentication::getPrincipal).filter(CustomUserDetails.class::isInstance)
            .map(CustomUserDetails.class::cast).map(CustomUserDetails::getUserId).orElse(null);
}

From source file:ch.ifocusit.livingdoc.plugin.utils.AsciidocUtil.java

public static Optional<String> getTitle(Asciidoctor asciidoctor, String pageContent) {
    return Optional.ofNullable(asciidoctor.readDocumentHeader(pageContent).getDocumentTitle())
            .map(title -> StringEscapeUtils.unescapeHtml4(title.getMain()));
}

From source file:pitayaa.nail.msg.core.account.service.AccountLicenseServiceImpl.java

@Override
public Optional<AccountLicense> findOne(UUID id) {
    return Optional.ofNullable(accountLicenseRepo.findOne(id));
}

From source file:cn.edu.zjnu.acm.judge.mapper.BestSubmissionsBuilder.java

public static String bestSubmissions(@Param("problemId") long problemId, @Param("pageable") Pageable pageable) {
    Set<String> dejaVu = new TreeSet<>(String.CASE_INSENSITIVE_ORDER);
    Sort sort = Optional.ofNullable(pageable.getSort()).map(s -> s.and(DEFAULT_SORT)).orElse(DEFAULT_SORT);
    Sort.Order[] orders = StreamSupport.stream(sort.spliterator(), false)
            .filter(order -> ALLOW_COLUMNS.contains(order.getProperty()) && dejaVu.add(order.getProperty()))
            .toArray(Sort.Order[]::new);
    final int length = orders.length;
    log.debug("{}", Arrays.asList(orders));

    StringBuilder sb = new StringBuilder(
            "select " + SubmissionMapper.LIST_COLUMNS + " from solution s where problem_id=").append(problemId)
                    .append(" and score=100 ");
    for (int i = length - 1; i >= 0; --i) {
        sb.append("and(user_id");
        for (int j = 0; j <= i; ++j) {
            sb.append(',').append(orders[j].getProperty());
        }//from w w  w .  ja v  a  2s .  com
        sb.append(")in(select user_id");
        for (int j = 0; j < i; ++j) {
            sb.append(',').append(orders[j].getProperty());
        }
        sb.append(',').append(orders[i].isAscending() ? "min" : "max").append("(")
                .append(orders[i].getProperty()).append(")").append(orders[i].getProperty())
                .append(" from solution where problem_id=").append(problemId).append(" and score=100 ");
    }
    for (int i = 0; i < length; ++i) {
        sb.append("group by user_id)");
    }
    if (length > 0) {
        sb.append(" order by ");
        for (int i = 0; i < length; ++i) {
            if (i > 0) {
                sb.append(",");
            }
            sb.append(orders[i].getProperty());
            if (!orders[i].isAscending()) {
                sb.append(" desc");
            }
        }
    }
    return sb.append(" limit ").append(pageable.getOffset()).append(",").append(pageable.getPageSize())
            .toString();
}

From source file:pitayaa.nail.msg.core.license.service.LicenseServiceImpl.java

@Override
public Optional<License> findOne(UUID uid) {
    return Optional.ofNullable(licenseRepo.findOne(uid));
}

From source file:Main.java

/**
 * @param <T> the key type/*from w  w  w  .ja  v a 2s .c om*/
 * @param s the set
 * @return an <b>UNMODIFIABLE</b> Set&lt;T&gt;
 */
public static <T> Set<T> unmodifiableSet(Set<? extends T> s) {
    return Optional.ofNullable(s).map(Collections::unmodifiableSet).orElseGet(Collections::emptySet);
}

From source file:org.zalando.riptide.Actions.java

public static ThrowingFunction<ClientHttpResponse, URI, IOException> contentLocation() {
    return response -> Optional.ofNullable(response.getHeaders().getFirst(CONTENT_LOCATION)).map(URI::create)
            .orElse(null);/* w w w .j a va 2  s  . c  o  m*/
}

From source file:eu.esdihumboldt.hale.io.haleconnect.internal.UserServiceHelper.java

/**
 * Build a {@link Credentials} object. Any null values passed in will be
 * converted to an empty string.//w ww. j ava2s .co m
 * 
 * @param username the user name
 * @param password the password
 * @return a Credentials object with the given credentials
 */
public static Credentials buildCredentials(String username, String password) {
    Credentials credentials = new Credentials();
    credentials.setUsername(Optional.ofNullable(username).orElse(""));
    credentials.setPassword(Optional.ofNullable(password).orElse(""));
    return credentials;
}

From source file:Main.java

/**
 * @param <K> the key type// www  . j a v a  2  s. com
 * @param <V> the value type
 * @param m   the map
 *
 * @return an <b>UNMODIFIABLE</b> Map&lt;K, V&gt;
 */
public static <K, V> Map<? extends K, ? extends V> unmodifiableMap(Map<? extends K, ? extends V> m) {
    return Optional.ofNullable(m).map(Collections::unmodifiableMap).orElseGet(Collections::emptyMap);
}