本文整理了Java中org.apereo.cas.util.CollectionUtils.firstElement()方法的一些代码示例，展示了CollectionUtils.firstElement()的具体用法。这些代码示例主要来源于Github/Stackoverflow/Maven等平台，是从一些精选项目中提取出来的代码，具有较强的参考意义，能在一定程度帮忙到你。CollectionUtils.firstElement()方法的具体详情如下：
包路径：org.apereo.cas.util.CollectionUtils
类名称：CollectionUtils
方法名：firstElement

CollectionUtils.firstElement介绍

[英]Converts the provided object into a collection and return the first element, or empty.
[中]将提供的对象转换为集合并返回第一个元素，或为空。

代码示例

代码示例来源：origin: org.apereo.cas/cas-server-core-util-api

private static Optional<Object> getFirstAttributeByName(final Principal principal, final String attribute) {
  val value = principal.getAttributes().get(attribute);
  return CollectionUtils.firstElement(value);
}

代码示例来源：origin: org.apereo.cas/cas-server-support-x509-core

/**
 * Get alternate principal if alternate attribute configured.
 * @param certificate X509 Certificate of user
 * @return principal using alternate attribute or null if none configured
 */
protected String getAlternatePrincipal(final X509Certificate certificate) {
  if (alternatePrincipalAttribute == null) {
    return null;
  }
  val attributes = extractPersonAttributes(certificate);
  val attribute = attributes.get(alternatePrincipalAttribute);
  if (attribute == null) {
    LOGGER.debug("Attempt to get alternate principal with attribute {} was unsuccessful.", alternatePrincipalAttribute);
    return null;
  }
  val optionalAttribute = CollectionUtils.firstElement(attribute);
  if (optionalAttribute.isEmpty()) {
    LOGGER.debug("Alternate attribute list for {} was empty.", alternatePrincipalAttribute);
    return null;
  }
  val alternatePrincipal = optionalAttribute.get().toString();
  if (StringUtils.isNotEmpty(alternatePrincipal)) {
    LOGGER.debug("Using alternate principal attribute {} ", alternatePrincipal);
    return alternatePrincipal;
  }
  LOGGER.debug("Returning null principal id...");
  return null;
}

代码示例来源：origin: org.apereo.cas/cas-server-core-authentication-api

LOGGER.debug("Found attribute [{}] with value(s) [{}]", key, values);
if (values.size() == 1) {
  val value = CollectionUtils.firstElement(values).get();
  convertedAttributes.put(key, value);
} else {
  val values = result.get();
  if (!values.isEmpty()) {
    principalId = CollectionUtils.firstElement(values).get().toString();
    LOGGER.debug("Found principal id attribute value [{}] and removed it from the collection of attributes", principalId);

代码示例来源：origin: org.apereo.cas/cas-server-core-services-api

@Override
public String generate(final Principal principal, final Service service) {
  val attributes = principal.getAttributes();
  LOGGER.debug("Found principal attributes [{}] to use when generating persistent identifiers", attributes);
  val principalId = FunctionUtils.doIf(
    StringUtils.isNotBlank(this.attribute) && attributes.containsKey(this.attribute),
    () -> {
      val attributeValue = attributes.get(this.attribute);
      LOGGER.debug("Using attribute [{}] to establish principal id", this.attribute);
      return CollectionUtils.firstElement(attributeValue).get().toString();
    },
    () -> {
      LOGGER.debug("Using principal id [{}] to generate persistent identifier", principal.getId());
      return principal.getId();
    }
  ).get();
  return generate(principalId, service != null ? service.getId() : null);
}

代码示例来源：origin: org.apereo.cas/cas-server-core-authentication-mfa-api

@Override
public Optional<MultifactorAuthenticationProvider> isActivated(final Authentication authentication,
                                final RegisteredService registeredService,
                                final HttpServletRequest httpServletRequest, final Service service) {
  if (authentication == null) {
    LOGGER.debug("No authentication is available to determine event for principal");
    return Optional.empty();
  }
  val principal = getPrincipalForMultifactorAuthentication(authentication);
  val result = resolveMultifactorAuthenticationProvider(Optional.empty(), registeredService, principal);
  if (result != null && !result.isEmpty()) {
    val id = CollectionUtils.firstElement(result);
    return MultifactorAuthenticationUtils.getMultifactorAuthenticationProviderById(id.toString(), ApplicationContextProvider.getApplicationContext());
  }
  return Optional.empty();
}

代码示例来源：origin: org.apereo.cas/cas-server-support-wsfederation

val result = CollectionUtils.firstElement(idAttributeAsList);
if (result.isPresent()) {
  val principalId = result.get().toString();

代码示例来源：origin: org.apereo.cas/cas-server-core-tickets-api

@Override
protected String getExpirationPolicyNameFor(final TicketState ticketState) {
  val attrs = ticketState.getAuthentication().getAttributes();
  val rememberMeRes = CollectionUtils.firstElement(attrs.get(RememberMeCredential.AUTHENTICATION_ATTRIBUTE_REMEMBER_ME));
  if (rememberMeRes.isEmpty()) {
    return PolicyTypes.DEFAULT.name();
  }
  val b = (Boolean) rememberMeRes.get();
  if (b.equals(Boolean.FALSE)) {
    LOGGER.trace("Ticket is not associated with a remember-me authentication.");
    return PolicyTypes.DEFAULT.name();
  }
  return PolicyTypes.REMEMBER_ME.name();
}

代码示例来源：origin: org.apereo.cas/cas-server-core-authentication-mfa-api

val isBypass = Boolean.class.cast(CollectionUtils.firstElement(attributes.get(MultifactorAuthenticationProviderBypass.AUTHENTICATION_ATTRIBUTE_BYPASS_MFA)).get());
val bypassedId = CollectionUtils.firstElement(attributes.get(MultifactorAuthenticationProviderBypass.AUTHENTICATION_ATTRIBUTE_BYPASS_MFA_PROVIDER)).get().toString();
LOGGER.trace("Found multifactor authentication bypass attributes for provider [{}]", bypassedId);
if (isBypass && StringUtils.equals(bypassedId, requestedContext)) {

代码示例来源：origin: org.apereo.cas/cas-server-core-authentication-attributes

/**
 * Decide if credential password should be released as attribute.
 * The credential must have been cached as an authentication attribute
 * and the attribute release policy must be allowed to release the
 * attribute.
 *
 * @param attributes     the attributes
 * @param authentication the authentication
 * @param service        the service
 */
protected void decideIfCredentialPasswordShouldBeReleasedAsAttribute(final Map<String, Object> attributes, final Authentication authentication,
                                   final RegisteredService service) {
  val policy = service.getAttributeReleasePolicy();
  val isAuthorized = policy != null && policy.isAuthorizedToReleaseCredentialPassword() && isAttributeAllowedForRelease(CasViewConstants.MODEL_ATTRIBUTE_NAME_PRINCIPAL_CREDENTIAL);
  val element = CollectionUtils.firstElement(authentication.getAttributes().get(CasViewConstants.MODEL_ATTRIBUTE_NAME_PRINCIPAL_CREDENTIAL));
  val credential = element.map(Object::toString).orElse(null);
  decideAttributeReleaseBasedOnServiceAttributePolicy(attributes, credential,
    CasViewConstants.MODEL_ATTRIBUTE_NAME_PRINCIPAL_CREDENTIAL, service, isAuthorized);
}

代码示例来源：origin: org.apereo.cas/cas-server-core-authentication-mfa-api

input -> providers.stream().anyMatch(provider -> input != null && provider.matches(input)));
if (result != null && !result.isEmpty()) {
  val id = CollectionUtils.firstElement(result);
  return MultifactorAuthenticationUtils.getMultifactorAuthenticationProviderById(id.toString(), applicationContext);

代码示例来源：origin: org.apereo.cas/cas-server-core-authentication-mfa-api

val id = CollectionUtils.firstElement(result);
return MultifactorAuthenticationUtils.getMultifactorAuthenticationProviderById(id.toString(), ApplicationContextProvider.getApplicationContext());

代码示例来源：origin: org.apereo.cas/cas-server-support-pac4j-core

@Override
  public void authorize(final HttpServletRequest request, final Service service, final Assertion assertion) {
    val registeredService = this.servicesManager.findServiceBy(service);
    RegisteredServiceAccessStrategyUtils.ensureServiceAccessIsAllowed(service, registeredService);
    LOGGER.debug("Evaluating service [{}] for delegated authentication policy", service);
    val policy = registeredService.getAccessStrategy().getDelegatedAuthenticationPolicy();
    if (policy != null) {
      val attributes = assertion.getPrimaryAuthentication().getAttributes();

      if (attributes.containsKey(ClientCredential.AUTHENTICATION_ATTRIBUTE_CLIENT_NAME)) {
        val clientNameAttr = attributes.get(ClientCredential.AUTHENTICATION_ATTRIBUTE_CLIENT_NAME);
        val value = CollectionUtils.firstElement(clientNameAttr);
        if (value.isPresent()) {
          val client = value.get().toString();
          LOGGER.debug("Evaluating delegated authentication policy [{}] for client [{}] and service [{}]", policy, client, registeredService);

          val context = AuditableContext.builder()
            .registeredService(registeredService)
            .properties(CollectionUtils.wrap(Client.class.getSimpleName(), client))
            .build();
          val result = delegatedAuthenticationPolicyEnforcer.execute(context);
          result.throwExceptionIfNeeded();
        }
      }
    }
  }
}