How to use

first

method

in

org.apache.sis.internal.util.CollectionsExt

/**
 * Invoked by JAXB {@link javax.xml.bind.Marshaller} before this object is marshalled to XML.
 * This method sets the locale to be used for XML marshalling to the metadata language.
 */
@SuppressWarnings("unused")
private void beforeMarshal(final Marshaller marshaller) {
  Context.push(CollectionsExt.first(languages));
}

/**
 * Returns the "main" namespace of the given factory, or {@code null} if none.
 * Current implementation returns the first namespace, but this may be changed in any future SIS version.
 *
 * <p>The purpose of this method is to get a unique identifier of a factory, ignoring version number.</p>
 */
static String getCodeSpace(final AuthorityFactory factory) {
  return CollectionsExt.first(getCodeSpaces(factory));
}

/**
 * Returns the "main" namespace of the given factory, or {@code null} if none.
 * Current implementation returns the first namespace, but this may be changed in any future SIS version.
 *
 * <p>The purpose of this method is to get a unique identifier of a factory, ignoring version number.</p>
 */
static String getCodeSpace(final AuthorityFactory factory) {
  return CollectionsExt.first(getCodeSpaces(factory));
}

/**
 * Invoked by JAXB {@link javax.xml.bind.Marshaller} before this object is marshalled to XML.
 * This method sets the locale to be used for XML marshalling to the metadata language.
 */
private void beforeMarshal(final Marshaller marshaller) {
  Context.push(CollectionsExt.first(languages));
}

/**
 * Gets the default locale for this record (used in ISO 19115-3 format).
 */
@XmlElement(name = "defaultLocale")
private Locale getDefaultLocale() {
  return FilterByVersion.CURRENT_METADATA.accept() ? CollectionsExt.first(getLanguages()) : null;
}

/**
 * Gets the default locale for this record (used in ISO 19115-3 format).
 */
@XmlElement(name = "defaultLocale")
private Locale getDefaultLocale() {
  return FilterByVersion.CURRENT_METADATA.accept() ? CollectionsExt.first(getLanguages()) : null;
}

/**
 * Returns the default language used for documenting metadata.
 *
 * @return language used for documenting metadata, or {@code null}.
 *
 * @deprecated As of GeoAPI 3.1, replaced by {@link #getLanguages()}.
 */
@Override
@Deprecated
@XmlElement(name = "language")
@Dependencies("getLanguages")
public Locale getLanguage() {
  return CollectionsExt.first(getLanguages());
  /*
   * No warning if the collection contains more than one locale, because
   * this is allowed by the "getLanguage() + getLocales()" contract.
   */
}

/**
 * Sets the other locales for this record (used in ISO 19115-3 format).
 */
private void setOtherLocales(final Collection<? extends Locale> newValues) {
  setLanguages(OtherLocales.merge(CollectionsExt.first(languages), newValues));
}

switch (collection.size()) {
  case 0:  collection = Collections.emptySet(); break;
  case 1:  collection = Collections.singleton(CollectionsExt.first(collection)); break;
  default: collection = Collections.unmodifiableSet(new LinkedHashSet<>(collection)); break;

switch (collection.size()) {
  case 0:  collection = Collections.emptySet(); break;
  case 1:  collection = Collections.singleton(CollectionsExt.first(collection)); break;
  default: collection = Collections.unmodifiableSet(new LinkedHashSet<>(collection)); break;

/**
 * Sets information about an alternatively used localized character string for a linguistic extension.
 *
 * @param  newValues  the new locales.
 *
 * @deprecated As of GeoAPI 3.1, replaced by {@link #setLanguages(Collection)}.
 */
@Deprecated
public void setLocales(final Collection<? extends Locale> newValues) {
  checkWritePermission();
  setLanguages(OtherLocales.merge(CollectionsExt.first(languages), newValues)); // See "Note about deprecated methods implementation"
}

/**
 * Returns the default language used for documenting metadata.
 *
 * @return language used for documenting metadata, or {@code null}.
 *
 * @deprecated As of SIS 0.5, replaced by {@link #getLanguages()}.
 */
@Override
@Deprecated
@Dependencies("getLanguages")
@XmlElement(name = "language", namespace = LegacyNamespaces.GMD)
@XmlJavaTypeAdapter(LocaleAdapter.class)
public Locale getLanguage() {
  return FilterByVersion.LEGACY_METADATA.accept() ? CollectionsExt.first(getLanguages()) : null;
  /*
   * No warning if the collection contains more than one locale, because
   * this is allowed by the "getLanguage() + getLocales()" contract.
   */
}

/**
 * If the given property is a link, returns the name of the referenced property.
 * Otherwise returns {@code null}.
 *
 * @param  property  the property to test, or {@code null} if none.
 * @return the referenced property name, or {@code null} if none.
 */
static String linkOf(final AbstractIdentifiedType property) {
  if (property instanceof AbstractOperation) {
    final AbstractOperation op = (AbstractOperation) property;
    if (op.getParameters() == LINK_PARAMS) {
      /*
       * The dependencies collection contains exactly one element on Apache SIS implementation.
       * However the user could define his own operation with the same parameter descriptor name.
       * This is unlikely since it would probably be a bug, but we are paranoiac.
       */
      return CollectionsExt.first(op.getDependencies());
    }
  }
  return null;
}

  /**
   * If the given property is a link, returns the name of the referenced property.
   * Otherwise returns {@code null}.
   *
   * @param  property  the property to test, or {@code null} if none.
   * @return the referenced property name, or {@code null} if none.
   */
  static String linkOf(final AbstractIdentifiedType property) {
    if (property instanceof AbstractOperation) {
      final AbstractOperation op = (AbstractOperation) property;
      if (op.getParameters() == LINK_PARAMS) {
        /*
         * The dependencies collection contains exactly one element on Apache SIS implementation.
         * However the user could define his own operation with the same parameter descriptor name.
         * This is unlikely since it would probably be a bug, but we are paranoiac.
         */
        return CollectionsExt.first(op.getDependencies());
      }
    }
    return null;
  }
}

GenericName name = first(wkt.getAlias());
if (name == null) {

GenericName name = first(wkt.getAlias());
if (name == null) {

checkWritePermission();
AbstractIdentification firstId = AbstractIdentification.castOrCopy(CollectionsExt.first(info));
if (firstId == null) {
  firstId = new DefaultDataIdentification();
DefaultOnlineResource firstOnline = DefaultOnlineResource.castOrCopy(CollectionsExt.first(onlineResources));
if (firstOnline == null) {
  firstOnline = new DefaultOnlineResource();

AbstractIdentification firstId = AbstractIdentification.castOrCopy(CollectionsExt.first(info));
if (firstId == null) {
  firstId = new DefaultDataIdentification();
DefaultOnlineResource firstOnline = DefaultOnlineResource.castOrCopy(CollectionsExt.first(onlineResources));
if (firstOnline == null) {
  firstOnline = new DefaultOnlineResource();

final InternationalString expectedAltTitle = first(fromDB.getAlternateTitles());
final InternationalString actualAltTitle   = first(fromFB.getAlternateTitles());
if (fromFB.getTitle().equals(expectedAltTitle)) {
  assertNull(name, actualAltTitle);
final Identifier expectedID = first(fromDB.getIdentifiers());
final Identifier actualID   = first(fromFB.getIdentifiers());
if (expectedID == null) {
  assertNull(name, actualID);
final ResponsibleParty expectedResp = first(fromDB.getCitedResponsibleParties());
final ResponsibleParty actualResp   = first(fromFB.getCitedResponsibleParties());
if (expectedResp == null) {
  assertNull(name, actualResp);
assertEquals(name, first(fromDB.getPresentationForms()),
          first(fromFB.getPresentationForms()));

final ResponsibleParty re = CollectionsExt.first(original.getCitedResponsibleParties());
final ResponsibleParty ra = CollectionsExt.first(clone   .getCitedResponsibleParties());
assertNotSame("citedResponsibleParty", re, ra);
assertSame("role", re.getRole(), ra.getRole());