Example usage for com.google.common.base Optional fromNullable

Introduction

In this page you can find the example usage for com.google.common.base Optional fromNullable.

Prototype

public static <T> Optional<T> fromNullable(@Nullable T nullableReference)

Source Link

Document

If nullableReference is non-null, returns an Optional instance containing that reference; otherwise returns Optional#absent .

Usage

From source file:com.shufudong.GuavaExample.collect.OptionalExample.java

/**
 * @return/*from  w w w  .ja  v  a  2 s. com*/
 * @category <p>??</p>
 * <ol>
 * <li>Optional.of(T)Optional??nullT?T=null</li>
 * <li>Optional.absent()Optional?</li>
 * <li>Optional.fromNullable(T)T?OptionalT???[Optional.fromNullable(null)Optional.absent()</li>
 * </ol>
 * @throw
 */
public static void testOptional2() throws Exception {
    Optional<Integer> possible = Optional.of(6);
    Optional<Integer> absentOpt = Optional.absent();
    Optional<Integer> NullableOpt = Optional.fromNullable(null);
    Optional<Integer> NoNullableOpt = Optional.fromNullable(10);
    if (possible.isPresent()) {
        System.out.println("possible isPresent:" + possible.isPresent());
        System.out.println("possible value:" + possible.get());
    }
    if (absentOpt.isPresent()) {
        System.out.println("absentOpt isPresent:" + absentOpt.isPresent());
    }
    if (NullableOpt.isPresent()) {
        System.out.println("fromNullableOpt isPresent:" + NullableOpt.isPresent());
    }
    if (NoNullableOpt.isPresent()) {
        System.out.println("NoNullableOpt isPresent:" + NoNullableOpt.isPresent());
    }
}

From source file:org.elasticsearch.river.subversion.crawler.LogEntryFilter.java

public LogEntryFilter(boolean contentToBeFiltered, boolean crawlingToBePrevented, String reason) {
    this.contentToBeFiltered = contentToBeFiltered;
    this.crawlingToBePrevented = crawlingToBePrevented;
    this.reason = Optional.fromNullable(reason);
}

From source file:org.geogig.osm.internal.log.ReadOSMMappingLogEntry.java

@Override
protected Optional<OSMMappingLogEntry> _call() {
    BlobStore blobStore = context().blobStore();
    final String pathPrefix = "osm/map/";
    final String path = pathPrefix + this.path;
    Optional<String> blob = Blobs.getBlobAsString(blobStore, path);
    OSMMappingLogEntry entry = null;/*  ww  w .  j a  v a2s .c om*/
    if (blob.isPresent()) {
        entry = OSMMappingLogEntry.fromString(blob.get());
    }
    return Optional.fromNullable(entry);
}

From source file:org.apache.hadoop.hdfs.protocolPB.ReconfigurationProtocolUtils.java

public static ReconfigurationTaskStatus getReconfigurationStatus(
        GetReconfigurationStatusResponseProto response) {
    Map<PropertyChange, Optional<String>> statusMap = null;
    long startTime;
    long endTime = 0;

    startTime = response.getStartTime();
    if (response.hasEndTime()) {
        endTime = response.getEndTime();
    }/*from  w  w  w  . j ava  2  s.co  m*/
    if (response.getChangesCount() > 0) {
        statusMap = Maps.newHashMap();
        for (GetReconfigurationStatusConfigChangeProto change : response.getChangesList()) {
            PropertyChange pc = new PropertyChange(change.getName(), change.getNewValue(),
                    change.getOldValue());
            String errorMessage = null;
            if (change.hasErrorMessage()) {
                errorMessage = change.getErrorMessage();
            }
            statusMap.put(pc, Optional.fromNullable(errorMessage));
        }
    }
    return new ReconfigurationTaskStatus(startTime, endTime, statusMap);
}

From source file:org.sonar.db.ce.CeActivityDao.java

public Optional<CeActivityDto> selectByUuid(DbSession dbSession, String uuid) {
    return Optional.fromNullable(mapper(dbSession).selectByUuid(uuid));
}

From source file:ec.tss.tsproviders.spreadsheet.engine.CellParser.java

@Nonnull
public Optional<T> tryParse(@Nonnull Sheet sheet, int rowIndex, int columnIndex) {
    return Optional.fromNullable(parse(sheet, rowIndex, columnIndex));
}

From source file:org.croudtrip.db.UserDAO.java

public Optional<User> findByEmail(String email) {
    return Optional.fromNullable(
            uniqueResult(namedQuery(User.QUERY_NAME_FIND_BY_EMAIL).setParameter(User.QUERY_PARAM_MAIL, email)));
}

From source file:net.pterodactylus.sonitus.data.DataPacket.java

/**
 * Creates a new data packet./*from  ww w  .j  a  v a  2  s .co m*/
 *
 * @param metadata
 *       The metadata (may be {@code null})
 * @param buffer
 *       The audio data
 */
public DataPacket(Metadata metadata, byte[] buffer) {
    this(Optional.fromNullable(metadata), buffer);
}

From source file:springfox.documentation.schema.Annotations.java

@SuppressWarnings("PMD")
private static <A extends Annotation> Optional<A> tryGetGetterAnnotation(
        BeanPropertyDefinition beanPropertyDefinition, Class<A> annotationClass) {

    if (beanPropertyDefinition.hasGetter()) {
        return Optional.fromNullable(beanPropertyDefinition.getGetter().getAnnotation(annotationClass));
    }//  w  w w. j  a v  a2  s  .c  om
    return Optional.absent();
}

From source file:com.spotify.heroic.elasticsearch.NodeClientSetup.java

@JsonCreator
public NodeClientSetup(String clusterName, List<String> seeds) {
    this.clusterName = Optional.fromNullable(clusterName).or(DEFAULT_CLUSTER_NAME);
    this.seeds = seedsToDiscovery(seeds);
}