Example usage for com.google.common.collect Iterables getOnlyElement

Introduction

In this page you can find the example usage for com.google.common.collect Iterables getOnlyElement.

Prototype

public static <T> T getOnlyElement(Iterable<T> iterable)

Source Link

Document

Returns the single element contained in iterable .

Usage

From source file:org.apache.calcite.rex.LogicVisitor.java

/** Finds a suitable logic for evaluating {@code seek} within a list of
 * expressions./*from w ww  .j a v a 2s.  co  m*/
 *
 * <p>Chooses a logic that is safe (that is, gives the right
 * answer) with the fewest possibilities (that is, we prefer one that
 * returns [true as true, false as false, unknown as false] over one that
 * distinguishes false from unknown).
 */
public static Logic find(Logic logic, List<RexNode> nodes, RexNode seek) {
    final Set<Logic> set = EnumSet.noneOf(Logic.class);
    final LogicVisitor visitor = new LogicVisitor(seek, set);
    for (RexNode node : nodes) {
        node.accept(visitor, logic);
    }
    // Convert FALSE (which can only exist within LogicVisitor) to
    // UNKNOWN_AS_TRUE.
    if (set.remove(Logic.FALSE)) {
        set.add(Logic.UNKNOWN_AS_TRUE);
    }
    switch (set.size()) {
    case 0:
        throw new IllegalArgumentException("not found: " + seek);
    case 1:
        return Iterables.getOnlyElement(set);
    default:
        return Logic.TRUE_FALSE_UNKNOWN;
    }
}

From source file:io.druid.query.UnionDataSource.java

@Override
public List<String> getNames() {
    return Lists.transform(dataSources, new Function<TableDataSource, String>() {
        @Override//  w  w w.  j a  va2 s. c o m
        public String apply(TableDataSource input) {
            return Iterables.getOnlyElement(input.getNames());
        }
    });
}

From source file:org.apache.beam.sdk.fn.data.RemoteGrpcPortWrite.java

public static RemoteGrpcPortWrite fromPTransform(PTransform pTransform) throws InvalidProtocolBufferException {
    checkArgument(URN.equals(pTransform.getSpec().getUrn()), "Expected URN for %s, got %s",
            RemoteGrpcPortWrite.class.getSimpleName(), pTransform.getSpec().getUrn());
    checkArgument(pTransform.getInputsCount() == 1, "Expected exactly one output, got %s",
            pTransform.getOutputsCount());
    RemoteGrpcPort port = RemoteGrpcPort.parseFrom(pTransform.getSpec().getPayload());
    String inputPCollectionId = Iterables.getOnlyElement(pTransform.getInputsMap().values());
    return writeToPort(inputPCollectionId, port);
}

From source file:org.jclouds.gogrid.functions.ParseLoadBalancerFromJsonResponse.java

@Override
public LoadBalancer apply(HttpResponse arg0) {
    return Iterables.getOnlyElement(parser.apply(arg0));
}

From source file:org.jclouds.aws.ec2.compute.predicates.AWSEC2InstancePresent.java

@Override
protected void refresh(RegionAndName instance) {
    if (instance.getName().indexOf("sir-") != 0)
        super.refresh(instance);
    else// www  .  j  av  a2s  . c o m
        Iterables.getOnlyElement(client.getSpotInstanceServices()
                .describeSpotInstanceRequestsInRegion(instance.getRegion(), instance.getName()));
}

From source file:com.google.devtools.build.lib.query2.engine.ParallelQueryUtils.java

/**
 * Executes the given {@link QueryTask}s using the given {@link ForkJoinPool} and interruptibly
 * waits for their completion. Throws the first {@link QueryException} encountered during parallel
 * execution or an {@link InterruptedException} if the calling thread is interrupted.
 *
 * <p>These "fail-fast" semantics are desirable to avoid doing unneeded work when evaluating
 * multiple {@link QueryTask}s in parallel: if serial execution of the tasks would result in a
 * {@link QueryException} then we want parallel execution to do so as well, but there's no need to
 * continue waiting for completion of the tasks after at least one of them results in a
 * {@link QueryException}./* w  w w  .ja  v  a2  s .  c  o  m*/
 */
public static void executeQueryTasksAndWaitInterruptiblyFailFast(List<QueryTask> queryTasks,
        ForkJoinPool forkJoinPool) throws QueryException, InterruptedException {
    int numTasks = queryTasks.size();
    if (numTasks == 1) {
        Iterables.getOnlyElement(queryTasks).execute();
        return;
    }
    FailFastCountDownLatch failFastLatch = new FailFastCountDownLatch(numTasks);
    ArrayList<QueryTaskForkJoinTask> forkJoinTasks = new ArrayList<>(numTasks);
    for (QueryTask queryTask : queryTasks) {
        QueryTaskForkJoinTask forkJoinTask = adaptAsForkJoinTask(queryTask, failFastLatch);
        forkJoinTasks.add(forkJoinTask);
        forkJoinPool.submit(forkJoinTask);
    }
    failFastLatch.await();
    try {
        MoreFutures.waitForAllInterruptiblyFailFast(forkJoinTasks);
    } catch (ExecutionException e) {
        throw rethrowCause(e);
    }
}

From source file:org.jclouds.aws.ec2.predicates.VolumeAvailable.java

public boolean apply(Volume volume) {
    logger.trace("looking for status on volume %s", volume.getId());
    volume = Iterables.getOnlyElement(client.describeVolumesInRegion(volume.getRegion(), volume.getId()));
    logger.trace("%s: looking for status %s: currently: %s", volume, Volume.Status.AVAILABLE,
            volume.getStatus());//from w ww .j a va 2s .  c o  m
    return volume.getStatus() == Volume.Status.AVAILABLE;
}

From source file:com.opengamma.provider.security.impl.RemoteSecurityEnhancer.java

@Override
public Security enhanceSecurity(Security security) {
    SecurityEnhancerRequest request = SecurityEnhancerRequest.create(security);
    SecurityEnhancerResult result = enhanceSecurities(request);
    return Iterables.getOnlyElement(result.getResultList());
}

From source file:org.jclouds.sqs.xml.RegexQueueHandler.java

@Override
public URI apply(HttpResponse response) {
    return Iterables.getOnlyElement(parse(returnStringIf200.apply(response)));
}

From source file:com.google.gerrit.server.query.Predicate.java

/** Combine the passed predicates into a single AND node. */
public static <T> Predicate<T> and(final Collection<? extends Predicate<T>> that) {
    if (that.size() == 1) {
        return Iterables.getOnlyElement(that);
    }//from w w  w  . j a  v  a  2s  .  c  o m
    return new AndPredicate<T>(that);
}