com.google.common.collect.Iterators#getLast ( )源码实例Demo

private static Set<DecoratedKey> getPaged(ColumnFamilyStore store, int pageSize, IndexExpression... expressions)
{
    List<Row> currentPage;
    Set<DecoratedKey> uniqueKeys = new TreeSet<>();

    DecoratedKey lastKey = null;
    do
    {
        currentPage = getIndexed(store, new IdentityQueryFilter(), lastKey, pageSize, expressions);

        if (currentPage == null)
            break;

        for (Row row : currentPage)
            uniqueKeys.add(row.key);

        Row lastRow = Iterators.getLast(currentPage.iterator(), null);
        if (lastRow == null)
            break;

        lastKey = lastRow.key;
    }
    while (currentPage.size() == pageSize);

    return uniqueKeys;
}
 

private static int updateColumn(int columnI, String originalTokText) {
    Integer last = Iterators.getLast(Newlines.lineOffsetIterator(originalTokText));
    if (last > 0) {
        columnI = originalTokText.length() - last;
    } else {
        columnI += originalTokText.length();
    }
    return columnI;
}
 

/**
 * 获取Collection的最后一个元素，如果collection为空返回null.
 */
public static <T> T getLast(Collection<T> collection) {
	if (isEmpty(collection)) {
		return null;
	}

	// 当类型List时，直接取得最后一个元素.
	if (collection instanceof List) {
		List<T> list = (List<T>) collection;
		return list.get(list.size() - 1);
	}

	return Iterators.getLast(collection.iterator());
}
 

@Test
public void hasNextErrorStack() throws Exception {
    final Iterator<String> erring = new BrokenCursor();
    try {
        Iterators.getLast(erring, null);
    } catch (Exception ex) {
        for (Throwable t = ex; t != null; t = t.getCause()) {
            if (Arrays.stream(t.getStackTrace()).anyMatch(s -> s.getMethodName().equals("getLast"))) {
                return;
            }
        }
        fail("did not find getLast() on stack");
    }
}
 

@Override
public TableSchema getSchema(String featureSet) {
  Map<String, Iterable<TableSchema>> schemasValue = sideInput(schemas);
  Iterable<TableSchema> schemasIt = schemasValue.get(featureSet);
  if (schemasIt == null) {
    return null;
  }
  return Iterators.getLast(schemasIt.iterator());
}
 

/**
 * 获取Collection的最后一个元素，如果collection为空返回null.
 */
public static <T> T getLast(Collection<T> collection) {
	if (isEmpty(collection)) {
		return null;
	}

	// 当类型List时，直接取得最后一个元素.
	if (collection instanceof List) {
		List<T> list = (List<T>) collection;
		return list.get(list.size() - 1);
	}

	return Iterators.getLast(collection.iterator());
}
 

private static int updateColumn(int columnI, String originalTokText) {
    Integer last = Iterators.getLast(Newlines.lineOffsetIterator(originalTokText));
    if (last > 0) {
        columnI = originalTokText.length() - last;
    } else {
        columnI += originalTokText.length();
    }
    return columnI;
}
 

/**
 * 获取Collection的最后一个元素，如果collection为空返回null.
 */
public static <T> T getLast(Collection<T> collection) {
	if (isEmpty(collection)) {
		return null;
	}

	// 当类型List时，直接取得最后一个元素.
	if (collection instanceof List) {
		List<T> list = (List<T>) collection;
		return list.get(list.size() - 1);
	}

	return Iterators.getLast(collection.iterator());
}
 

protected Spatial getPrevious( Spatial from ) {       
    Spatial previous = Iterators.getLast(new ChildIterator(null, from, TraversalDirection.PageEnd), null);
    if( previous == null && focusRoot ) {
        previous = getLast();
    }
    return previous;
}
 

private static int updateColumn(int columnI, String originalTokText) {
  Integer last = Iterators.getLast(Newlines.lineOffsetIterator(originalTokText));
  if (last > 0) {
    columnI = originalTokText.length() - last;
  } else {
    columnI += originalTokText.length();
  }
  return columnI;
}
 

@Override
public State computeBreaks(CommentsHelper commentsHelper, int maxWidth, State state) {
  text = commentsHelper.rewrite(tok, maxWidth, state.column);
  int firstLineLength = text.length() - Iterators.getLast(Newlines.lineOffsetIterator(text));
  return state.withColumn(state.column + firstLineLength);
}
 

@ProcessElement
public void processElement(ProcessContext context) {
  String error = null;
  FeatureRow featureRow = context.element();
  Iterable<FeatureSetProto.FeatureSetSpec> featureSetSpecs =
      context.sideInput(getFeatureSets()).get(featureRow.getFeatureSet());

  List<FieldProto.Field> fields = new ArrayList<>();
  if (featureSetSpecs != null) {
    FeatureSetProto.FeatureSetSpec latestSpec = Iterators.getLast(featureSetSpecs.iterator());
    FeatureSet featureSet = new FeatureSet(latestSpec);

    for (FieldProto.Field field : featureRow.getFieldsList()) {
      Field fieldSpec = featureSet.getField(field.getName());
      if (fieldSpec == null) {
        // skip
        continue;
      }
      // If value is set in the FeatureRow, make sure the value type matches
      // that defined in FeatureSetSpec
      if (!field.getValue().getValCase().equals(ValCase.VAL_NOT_SET)) {
        int expectedTypeFieldNumber = fieldSpec.getType().getNumber();
        int actualTypeFieldNumber = field.getValue().getValCase().getNumber();
        if (expectedTypeFieldNumber != actualTypeFieldNumber) {
          error =
              String.format(
                  "FeatureRow contains field '%s' with invalid type '%s'. Feast expects the field type to match that in FeatureSet '%s'. Please check the FeatureRow data.",
                  field.getName(), field.getValue().getValCase(), fieldSpec.getType());
          break;
        }
      }
      if (!fields.contains(field)) {
        fields.add(field);
      }
    }
  } else {
    error =
        String.format(
            "FeatureRow contains invalid feature set id %s. Please check that the feature rows are being published to the correct topic on the feature stream.",
            featureRow.getFeatureSet());
  }

  if (error != null) {
    FailedElement.Builder failedElement =
        FailedElement.newBuilder()
            .setTransformName("ValidateFeatureRow")
            .setJobName(context.getPipelineOptions().getJobName())
            .setPayload(featureRow.toString())
            .setErrorMessage(error);
    if (featureSetSpecs != null) {
      FeatureSetProto.FeatureSetSpec spec = Iterators.getLast(featureSetSpecs.iterator());
      failedElement =
          failedElement.setProjectName(spec.getProject()).setFeatureSetName(spec.getName());
    }
    context.output(getFailureTag(), failedElement.build());
  } else {
    featureRow = featureRow.toBuilder().clearFields().addAllFields(fields).build();
    context.output(getSuccessTag(), featureRow);
  }
}
 

@Override
public State computeBreaks(CommentsHelper commentsHelper, int maxWidth, State state) {
  text = commentsHelper.rewrite(tok, maxWidth, state.column);
  int firstLineLength = text.length() - Iterators.getLast(Newlines.lineOffsetIterator(text));
  return state.withColumn(state.column + firstLineLength);
}
 

protected Spatial getLast() {
    return Iterators.getLast(new ChildIterator(TraversalDirection.PageEnd), null);
}
 

/**
 * Returns the best results. It takes all the elements which have been rated the best
 * and returns the first / last, depending on the parameter.
 *
 * @param results          The results to check
 * @param firstResult      If the first element of the best element list should be returned.
 * @param referenceElement
 * @return The result
 */
private PsiElement findBestResult(Multimap<Integer, PsiElement> results, boolean firstResult, PsiElement referenceElement) {
    if (!hasResults()) {
        return null;
    }

    if (firstResult) {
        return Iterators.get(results.values().iterator(), 0);
    }

    //if the first should not be used return the best element
    int referenceLevel = preferNeigbourhood && (referenceElement != null) ? BashPsiUtils.blockNestingLevel(referenceElement) : 0;

    // find the best suitable result rating
    // The best one is as close as possible to the given referenceElement
    int bestRating = Integer.MAX_VALUE;
    int bestDelta = Integer.MAX_VALUE;
    for (int rating : results.keySet()) {
        final int delta = Math.abs(referenceLevel - rating);
        if (delta < bestDelta) {
            bestDelta = delta;
            bestRating = rating;
        }
    }

    // now get the best result
    // if there are equal definitions on the same level we prefer the first if the neighbourhood is not preferred
    if (preferNeigbourhood) {
        return Iterators.getLast(results.get(bestRating).iterator());
    } else {
        //return the element which has the lowest textOffset
        long smallestOffset = Integer.MAX_VALUE;
        PsiElement bestElement = null;

        for (PsiElement e : results.get(bestRating)) {
            //if the element is injected compute the text offset in the real file
            int textOffset = e.getTextOffset();
            if (BashPsiUtils.isInjectedElement(e)) {
                //fixme optimize this
                PsiLanguageInjectionHost injectionHost = InjectedLanguageManager.getInstance(e.getProject()).getInjectionHost(e);
                if (injectionHost != null) {
                    textOffset = textOffset + injectionHost.getTextOffset();
                }
            }

            // comparing the offset is only meaningful within the same file
            // for definitions in included files we need to compare against the offset of the include command
            Collection<PsiElement> includeCommands = this.includeCommands != null ? this.includeCommands.get(e) : Collections.emptyList();
            if (!includeCommands.isEmpty()) {
                for (PsiElement includeCommand : includeCommands) {
                    int includeOffset = includeCommand.getTextOffset();
                    if (includeOffset < smallestOffset) {
                        smallestOffset = includeOffset;
                        bestElement = e;
                    }
                }
            } else if (textOffset < smallestOffset) {
                smallestOffset = textOffset;
                bestElement = e;
            }
        }

        return bestElement;
    }
}
 

@Override
default V lastValue(final IScope scope) throws GamaRuntimeException {
	if (length(scope) == 0) { return null; }
	return Iterators.getLast(values().iterator());
}
 

@Override
public State computeBreaks(CommentsHelper commentsHelper, int maxWidth, State state) {
  text = commentsHelper.rewrite(tok, maxWidth, state.column);
  int firstLineLength = text.length() - Iterators.getLast(Newlines.lineOffsetIterator(text));
  return state.withColumn(state.column + firstLineLength);
}