本文整理了Java中java.util.Optional.ifPresent()方法的一些代码示例，展示了Optional.ifPresent()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。Optional.ifPresent()方法的具体详情如下：
包路径：java.util.Optional
类名称：Optional
方法名：ifPresent

Optional.ifPresent介绍

[英]If a value is present, invoke the specified consumer with the value, otherwise do nothing.
[中]如果存在值，则使用该值调用指定的使用者，否则不执行任何操作。

代码示例

代码示例来源：origin: prestodb/presto

@Override
public List<Node> getChildren()
{
  ImmutableList.Builder<Node> nodes = ImmutableList.builder();
  window.ifPresent(nodes::add);
  filter.ifPresent(nodes::add);
  orderBy.map(OrderBy::getSortItems).map(nodes::addAll);
  nodes.addAll(arguments);
  return nodes.build();
}

代码示例来源：origin: prestodb/presto

public void rollback()
{
  Optional.ofNullable(rollbackAction.getAndSet(null)).ifPresent(Runnable::run);
}

代码示例来源：origin: neo4j/neo4j

public void forEach( BiConsumer<String,URI> consumer )
{
  entries.stream().collect( Collectors.groupingBy( e -> e.key ) )
      .forEach( ( key, list ) -> list.stream()
          .max( Comparator.comparing( e -> e.precedence ) )
          .ifPresent( e -> consumer.accept( key, e.uri ) ) );
}

代码示例来源：origin: ethereum/ethereumj

public DefaultConfig() {
  Thread.setDefaultUncaughtExceptionHandler((t, e) -> {
    logger.error("Uncaught exception", e);
    FATAL_EXCEPTIONS.stream()
        .filter(errType -> errType.isInstance(e))
        .findFirst()
        .ifPresent(errType -> System.exit(1));
  });
}

代码示例来源：origin: prestodb/presto

private void validateSelectors(List<ResourceGroupSpec> groups, SelectorSpec spec)
{
  spec.getQueryType().ifPresent(this::validateQueryType);
  List<ResourceGroupNameTemplate> selectorGroups = spec.getGroup().getSegments();
  StringBuilder fullyQualifiedGroupName = new StringBuilder();
  while (!selectorGroups.isEmpty()) {
    ResourceGroupNameTemplate groupName = selectorGroups.get(0);
    fullyQualifiedGroupName.append(groupName);
    Optional<ResourceGroupSpec> match = groups
        .stream()
        .filter(groupSpec -> groupSpec.getName().equals(groupName))
        .findFirst();
    if (!match.isPresent()) {
      throw new IllegalArgumentException(format("Selector refers to nonexistent group: %s", fullyQualifiedGroupName.toString()));
    }
    fullyQualifiedGroupName.append(".");
    groups = match.get().getSubGroups();
    selectorGroups = selectorGroups.subList(1, selectorGroups.size());
  }
}

代码示例来源：origin: apache/incubator-dubbo

@Override
public synchronized void notify(List<URL> urls) {
  List<URL> categoryUrls = urls.stream()
      .filter(this::isValidCategory)
      .filter(this::isNotCompatibleFor26x)
      .collect(Collectors.toList());
  /**
   * TODO Try to refactor the processing of these three type of urls using Collectors.groupBy()?
   */
  this.configurators = Configurator.toConfigurators(classifyUrls(categoryUrls, UrlUtils::isConfigurator))
      .orElse(configurators);
  toRouters(classifyUrls(categoryUrls, UrlUtils::isRoute)).ifPresent(this::addRouters);
  // providers
  refreshOverrideAndInvoker(classifyUrls(categoryUrls, UrlUtils::isProvider));
}

代码示例来源：origin: jenkinsci/jenkins

/**
 * Returns initial {@link Method} as well as all matching ones found in interfaces.
 * This allows to introspect metadata for a method which is both declared in parent class and in implemented
 * interface(s). <code>interfaces</code> typically is obtained by {@link ClassUtils#getAllInterfacesAsSet}
 */
Collection<Method> getMethodAndInterfaceDeclarations(Method method, Collection<Class> interfaces) {
  final List<Method> methods = new ArrayList<>();
  methods.add(method);
  // we search for matching method by iteration and comparison vs getMethod to avoid repeated NoSuchMethodException
  // being thrown, while interface typically only define a few set of methods to check.
  interfaces.stream()
      .map(Class::getMethods)
      .flatMap(Arrays::stream)
      .filter(m -> m.getName().equals(method.getName()) && Arrays.equals(m.getParameterTypes(), method.getParameterTypes()))
      .findFirst()
      .ifPresent(methods::add);
  return methods;
}

代码示例来源：origin: prestodb/presto

public String getBearerToken(String subject)
{
  checkState(jwtSigner.isPresent(), "not configured");
  JwtBuilder jwt = Jwts.builder()
      .setSubject(subject)
      .setExpiration(Date.from(ZonedDateTime.now().plusMinutes(5).toInstant()));
  jwtSigner.get().accept(jwt);
  jwtKeyId.ifPresent(keyId -> jwt.setHeaderParam(KEY_ID, keyId));
  jwtIssuer.ifPresent(jwt::setIssuer);
  jwtAudience.ifPresent(jwt::setAudience);
  return jwt.compact();
}

代码示例来源：origin: SonarSource/sonarqube

private static void addPullRequest(ProjectPullRequests.ListWsResponse.Builder response, BranchDto branch, Map<String, BranchDto> mergeBranchesByUuid,
 @Nullable LiveMeasureDto qualityGateMeasure, BranchStatistics branchStatistics, @Nullable String analysisDate) {
 Optional<BranchDto> mergeBranch = Optional.ofNullable(mergeBranchesByUuid.get(branch.getMergeBranchUuid()));
 ProjectPullRequests.PullRequest.Builder builder = ProjectPullRequests.PullRequest.newBuilder();
 builder.setKey(branch.getKey());
 DbProjectBranches.PullRequestData pullRequestData = requireNonNull(branch.getPullRequestData(), "Pull request data should be available for branch type PULL_REQUEST");
 builder.setBranch(pullRequestData.getBranch());
 ofNullable(emptyToNull(pullRequestData.getUrl())).ifPresent(builder::setUrl);
 ofNullable(emptyToNull(pullRequestData.getTitle())).ifPresent(builder::setTitle);
 if (mergeBranch.isPresent()) {
  String mergeBranchKey = mergeBranch.get().getKey();
  builder.setBase(mergeBranchKey);
 } else {
  builder.setIsOrphan(true);
 }
 ofNullable(analysisDate).ifPresent(builder::setAnalysisDate);
 setQualityGate(builder, qualityGateMeasure, branchStatistics);
 response.addPullRequests(builder);
}

代码示例来源：origin: prestodb/presto

private static void addAllStages(Optional<StageInfo> stageInfo, ImmutableList.Builder<StageInfo> collector)
{
  stageInfo.ifPresent(stage -> {
    collector.add(stage);
    stage.getSubStages().stream()
        .forEach(subStage -> addAllStages(Optional.ofNullable(subStage), collector));
  });
}

代码示例来源：origin: prestodb/presto

private void analyzeHaving(QuerySpecification node, Scope scope)
{
  if (node.getHaving().isPresent()) {
    Expression predicate = node.getHaving().get();
    ExpressionAnalysis expressionAnalysis = analyzeExpression(predicate, scope);
    expressionAnalysis.getWindowFunctions().stream()
        .findFirst()
        .ifPresent(function -> {
          throw new SemanticException(NESTED_WINDOW, function.getNode(), "HAVING clause cannot contain window functions");
        });
    analysis.recordSubqueries(node, expressionAnalysis);
    Type predicateType = expressionAnalysis.getType(predicate);
    if (!predicateType.equals(BOOLEAN) && !predicateType.equals(UNKNOWN)) {
      throw new SemanticException(TYPE_MISMATCH, predicate, "HAVING clause must evaluate to a boolean: actual type %s", predicateType);
    }
    analysis.setHaving(node, predicate);
  }
}

代码示例来源：origin: prestodb/presto

private void flattenNode(PlanNode node, int limit)
{
  PlanNode resolved = lookup.resolve(node);
  // (limit - 2) because you need to account for adding left and right side
  if (!(resolved instanceof JoinNode) || (sources.size() > (limit - 2))) {
    sources.add(node);
    return;
  }
  JoinNode joinNode = (JoinNode) resolved;
  if (joinNode.getType() != INNER || !isDeterministic(joinNode.getFilter().orElse(TRUE_LITERAL)) || joinNode.getDistributionType().isPresent()) {
    sources.add(node);
    return;
  }
  // we set the left limit to limit - 1 to account for the node on the right
  flattenNode(joinNode.getLeft(), limit - 1);
  flattenNode(joinNode.getRight(), limit);
  joinNode.getCriteria().stream()
      .map(EquiJoinClause::toExpression)
      .forEach(filters::add);
  joinNode.getFilter().ifPresent(filters::add);
}

代码示例来源：origin: prestodb/presto

public static void checkTableName(String catalogName, Optional<String> schemaName, Optional<String> tableName)
{
  checkCatalogName(catalogName);
  schemaName.ifPresent(name -> checkLowerCase(name, "schemaName"));
  tableName.ifPresent(name -> checkLowerCase(name, "tableName"));
  checkArgument(schemaName.isPresent() || !tableName.isPresent(), "tableName specified but schemaName is missing");
}

代码示例来源：origin: SonarSource/sonarqube

private static void writeIfNeeded(String fieldName, @Nullable Date value, Consumer<String> setter, Set<String> desiredFields) {
 if (desiredFields.contains(fieldName)) {
  ofNullable(value).map(DateUtils::formatDateTime).ifPresent(setter);
 }
}

代码示例来源：origin: rest-assured/rest-assured

private Object[] resolvePathParams(Object[] pathParams) {
  Arrays.stream(pathParams).filter(param -> !(param instanceof String))
      .findAny().ifPresent(param -> {
    throw new IllegalArgumentException("Only Strings allowed in path parameters.");
  });
  return Arrays.stream(pathParams)
      .map(param -> UriUtils.encode((String) param, Charsets.UTF_8)).toArray();
}

代码示例来源：origin: spring-projects/spring-framework

/**
 * Checks whether all of the data buffers allocated by this factory have also been released.
 * If not, then an {@link AssertionError} is thrown. Typically used from a JUnit {@link After}
 * method.
 */
public void checkForLeaks() {
  this.created.stream()
      .filter(LeakAwareDataBuffer::isAllocated)
      .findFirst()
      .map(LeakAwareDataBuffer::leakError)
      .ifPresent(leakError -> {
        throw leakError;
      });
}

代码示例来源：origin: SonarSource/sonarqube

private List<Setting> loadSettings(DbSession dbSession, Optional<ComponentDto> component, Set<String> keys) {
 // List of settings must be kept in the following orders : default -> global -> component -> branch
 List<Setting> settings = new ArrayList<>();
 settings.addAll(loadDefaultValues(keys));
 settings.addAll(loadGlobalSettings(dbSession, keys));
 if (component.isPresent() && component.get().getBranch() != null && component.get().getMainBranchProjectUuid() != null) {
  ComponentDto project = dbClient.componentDao().selectOrFailByUuid(dbSession, component.get().getMainBranchProjectUuid());
  settings.addAll(loadComponentSettings(dbSession, keys, project).values());
 }
 component.ifPresent(componentDto -> settings.addAll(loadComponentSettings(dbSession, keys, componentDto).values()));
 return settings.stream()
  .filter(s -> settingsWsSupport.isVisible(s.getKey(), s.getDefinition(), component))
  .collect(Collectors.toList());
}

代码示例来源：origin: apache/incubator-dubbo

@Override
public synchronized void notify(List<URL> urls) {
  List<URL> categoryUrls = urls.stream()
      .filter(this::isValidCategory)
      .filter(this::isNotCompatibleFor26x)
      .collect(Collectors.toList());
  /**
   * TODO Try to refactor the processing of these three type of urls using Collectors.groupBy()?
   */
  this.configurators = Configurator.toConfigurators(classifyUrls(categoryUrls, UrlUtils::isConfigurator))
      .orElse(configurators);
  toRouters(classifyUrls(categoryUrls, UrlUtils::isRoute)).ifPresent(this::addRouters);
  // providers
  refreshOverrideAndInvoker(classifyUrls(categoryUrls, UrlUtils::isProvider));
}

代码示例来源：origin: apache/flink

/**
 * Validates that the given prefix is not included in these properties.
 */
public void validatePrefixExclusion(String prefix) {
  properties.keySet().stream()
    .filter(k -> k.startsWith(prefix))
    .findFirst()
    .ifPresent((k) -> {
      throw new ValidationException(
        "Properties with prefix '" + prefix + "' are not allowed in this context. " +
        "But property '" + k + "' was found.");
    });
}

代码示例来源：origin: SonarSource/sonarqube

private List<String> getValues() {
 Optional<String> value = readParam("value");
 if (!value.isPresent()) {
  List<String> values = new ArrayList<>();
  readBody().ifPresent(values::add);
  return values;
 }
 return VALUE_SPLITTER.splitToList(value.get());
}