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

/**
 * @param collectionOfCollection/*w w  w  .  j a  va2 s . co m*/
 *            a Collection&lt;Collection&lt;T>>
 *
 * @return a Set&lt;T> containing all values of all Collections&lt;T>
 *         without any duplicates
 */
public static <T> Set<T> unionOfListOfLists(
        Collection<? extends Collection<? extends T>> collectionOfCollection) {
    return Optional.ofNullable(collectionOfCollection).map(Collection::stream).orElseGet(Stream::empty)
            .filter(Objects::nonNull).flatMap(x -> x.stream()).filter(Objects::nonNull).collect(toSet());
}

From source file:de.perdian.commons.lang.conversion.support.DelegatingConverter.java

protected DelegatingConverter(Converter<? super A, ? extends B> delegee) {
    this.setDelegee(Optional.ofNullable(delegee)
            .orElseThrow(() -> new IllegalArgumentException("Parameter 'delegee' must not be null")));
}

From source file:net.hamnaberg.json.Link.java

public static Link create(URI href, String rel, Optional<String> prompt, Optional<String> name,
        Optional<Render> render) {
    ObjectNode node = JsonNodeFactory.instance.objectNode();
    node.put("href", Optional.ofNullable(href)
            .orElseThrow(() -> new IllegalArgumentException("Href may not be null")).toString());
    node.put("rel", Optional.ofNullable(rel)
            .orElseThrow(() -> new IllegalArgumentException("Relation may not be null")));
    prompt.ifPresent(value -> node.put("prompt", value));
    render.ifPresent(value -> node.put("render", value.getName()));
    name.ifPresent(value -> node.put("name", value));
    return new Link(node);
}

From source file:com.asakusafw.runtime.stage.launcher.Util.java

private static List<File> list(File file) {
    return Optional.ofNullable(file.listFiles()).map(Arrays::asList).orElse(Collections.emptyList());
}

From source file:co.runrightfast.vertx.core.eventbus.MessageHeader.java

public static Optional<String> getCorrelationId(@NonNull final Message message) {
    return Optional.ofNullable(message.headers().get(MESSAGE_CORRELATION_ID.header));
}

From source file:com.teradata.benchto.service.rest.requests.GetTagsRequest.java

public Optional<ZonedDateTime> getEnd() {
    return Optional.ofNullable(end);
}

From source file:org.trustedanalytics.serviceinfo.MqttServiceInfoCreator.java

@Override
public boolean accept(Map<String, Object> serviceData) {
    Optional<String> label = Optional.ofNullable((String) serviceData.get("label"));
    if (label.isPresent()) {
        return label.get().equals(MQTT_ID);
    }/* w w w.j  a  va  2  s  .  c o  m*/
    return false;
}

From source file:alfio.controller.support.SessionUtil.java

public static Optional<String> retrievePromotionCodeDiscount(HttpServletRequest request) {
    return Optional.ofNullable((String) request.getSession().getAttribute(PROMOTIONAL_CODE_DISCOUNT));
}

From source file:de.perdian.commons.lang.conversion.support.DefaultWhenNullConverter.java

@Override
public B convert(A source) {
    return Optional.ofNullable(super.convert(source)).orElseGet(this::getDefaultResult);
}

From source file:com.teradata.benchto.service.rest.requests.GetTagsRequest.java

public Optional<ZonedDateTime> getStart() {
    return Optional.ofNullable(start);
}