java.util.Collection#clear ( )源码实例Demo

boolean removeEntriesIf(Predicate<? super Entry<K, Collection<V>>> predicate) {
  Iterator<Entry<K, Collection<V>>> entryIterator = unfiltered.asMap().entrySet().iterator();
  boolean changed = false;
  while (entryIterator.hasNext()) {
    Entry<K, Collection<V>> entry = entryIterator.next();
    K key = entry.getKey();
    Collection<V> collection = filterCollection(entry.getValue(), new ValuePredicate(key));
    if (!collection.isEmpty()
        && predicate.apply(Maps.immutableEntry(key, collection))) {
      if (collection.size() == entry.getValue().size()) {
        entryIterator.remove();
      } else {
        collection.clear();
      }
      changed = true;
    }
  }
  return changed;
}
 

/** {@inheritDoc} */
@Override public void clear() {
    try {
        onAccess();

        try (GridCloseableIterator<T> iter = iterator0()) {
            Collection<SetItemKey> rmvKeys = new ArrayList<>(BATCH_SIZE);

            for (T val : iter) {
                rmvKeys.add(itemKey(val));

                if (rmvKeys.size() == BATCH_SIZE) {
                    retryRemoveAll(rmvKeys);

                    rmvKeys.clear();
                }
            }

            if (!rmvKeys.isEmpty())
                retryRemoveAll(rmvKeys);
        }
    }
    catch (IgniteCheckedException e) {
        throw U.convertException(e);
    }
}
 

private <T> Map<FutureResult, List<T>> waitForRequests(Collection<Future<ResourceRequestResult<T>>> futures) {
    Map<FutureResult, List<T>> result = new EnumMap<>(FutureResult.class);
    result.put(FutureResult.FAILED, new ArrayList<>());
    result.put(FutureResult.SUCCESS, new ArrayList<>());
    int requests = futures.size();
    LOGGER.debug("Waiting for {} requests to finish", requests);
    try {
        for (Future<ResourceRequestResult<T>> future : futures) {
            ResourceRequestResult<T> resourceRequestResult = future.get();
            if (FutureResult.FAILED == resourceRequestResult.getStatus()) {
                result.get(FutureResult.FAILED).add(resourceRequestResult.getResult());
            } else {
                result.get(FutureResult.SUCCESS).add(resourceRequestResult.getResult());
            }
        }
    } catch (InterruptedException | ExecutionException e) {
        LOGGER.error("Failed to execute the request", e);
    }
    LOGGER.debug("{} requests have finished, continue with next group", requests);
    futures.clear();
    return result;
}
 

/**
 * Returns a new collection containing clones of all the items in the
 * specified collection.
 *
 * @param collection the collection (<code>null</code> not permitted).
 * @return A new collection containing clones of all the items in the
 *         specified collection.
 * @throws CloneNotSupportedException if any of the items in the collection
 *                                    cannot be cloned.
 */
public static Collection deepClone(final Collection collection)
    throws CloneNotSupportedException {

    if (collection == null) {
        throw new IllegalArgumentException("Null 'collection' argument.");
    }
    // all JDK-Collections are cloneable ...
    // and if the collection is not clonable, then we should throw
    // a CloneNotSupportedException anyway ...
    final Collection result
        = (Collection) ObjectUtilities.clone(collection);
    result.clear();
    final Iterator iterator = collection.iterator();
    while (iterator.hasNext()) {
        final Object item = iterator.next();
        if (item != null) {
            result.add(clone(item));
        }
        else {
            result.add(null);
        }
    }
    return result;
}
 

@Override
public void filter( List< PointMatch > candidates, Collection< PointMatch > inliers )
{
	try
	{
		if (
			!model.filterRansac(
					candidates,
					inliers,
					iterations,
					maxEpsilon,
					minInlierRatio,
					minNumInliers,
					maxTrust ) )
			inliers.clear();
	}
	catch ( Exception e )
	{
		inliers.clear();
	}
}
 

public void updateValueFromChildren(TypeNodeData inData) {
    /**
     * create a new ArrayList from all of the child values.
     */
    TypeNodeData data = (TypeNodeData)this.getUserObject();
    
    Collection c = (Collection)data.getTypeValue();
    if (c == null) return;
    
    c.clear();
    for(int ii=0; ii < this.getChildCount(); ii++) {
        DefaultMutableTreeNode childNode = (DefaultMutableTreeNode)this.getChildAt(ii);
        TypeNodeData childData = (TypeNodeData)childNode.getUserObject();
        if(null != childData.getTypeValue()) {
            c.add(childData.getTypeValue());
        }
    }
    
    DefaultMutableTreeNode parentNode = (DefaultMutableTreeNode) this.getParent();
    if (parentNode != null && parentNode instanceof ParameterTreeNode) {
        ((ParameterTreeNode)parentNode).updateValueFromChildren(data);
    }
}
 

/**
 * This chooses to record the results in the collection provided or discard
 * it.
 * <p>
 * If includeAllSolutions is true, then this solution is always recorded.
 * Otherwise this solution is only recorded if the complexity is the lowest
 * complexity yet detected.
 * 
 * @param results
 *            the collection to store the solution in if this method decides
 *            to keep it.
 * @param solution
 *            the new solution to process.
 * @param key
 *            the key describing the query being made.
 */
protected void processSolution(Collection<DiffSegment> results,
		DiffSegment solution, Key key, Complexity minComplexity) {
	boolean isValid = true;
	DiffSegment tail = solution.getTail();
	if (tail instanceof SplitSegment) {
		SplitSegment tailSplit = (SplitSegment) tail;

		if (tailSplit.textA.length() > 0 && tailSplit.textB.length() > 0) {
			char chA = tailSplit.textA.charAt(tailSplit.textA.length() - 1);
			char chB = tailSplit.textB.charAt(tailSplit.textB.length() - 1);
			if (chA == chB) {
				isValid = false;
			}
		}
	}
	if (!isValid)
		return;

	int complexity = solution.getComplexity();
	if (key.includeAllSolutions) {
		results.add(solution);
	} else {
		if ((!key.includeAllSolutions) && complexity < minComplexity.value) {
			results.clear();
			minComplexity.value = complexity;
		}
		if (complexity == minComplexity.value) {
			results.add(solution);
		}
	}
}
 

/**
* {@inheritDoc}
*
* <p>The returned collection is immutable.
*/

     @Override
     public Collection<V> removeAll(@Nullable Object key) {
 Collection<V> collection = map.remove(key);
 if (collection == null) {
         return createUnmodifiableEmptyCollection();
 }
 Collection<V> output = createCollection();
 output.addAll(collection);
 totalSize -= collection.size();
 collection.clear();
 return unmodifiableCollectionSubclass(output);
     }
 

final private String getEnrolmentsInfo() {
    final StringBuilder result = new StringBuilder();
    final EnrolmentCertificateRequest request = getDocumentRequest();

    if (request.getDetailed()) {
        final Collection<IEnrolment> enrolments =
                new TreeSet<>(Enrolment.COMPARATOR_BY_EXECUTION_YEAR_AND_NAME_AND_ID);

        enrolments.addAll(request.getEntriesToReport());
        reportEnrolments(result, enrolments);
        enrolments.clear();

        enrolments.addAll(request.getExtraCurricularEntriesToReport());
        if (!enrolments.isEmpty()) {
            reportRemainingEnrolments(result, enrolments, "Extra-Curriculares");
        }
        enrolments.clear();

        enrolments.addAll(request.getPropaedeuticEntriesToReport());
        if (!enrolments.isEmpty()) {
            reportRemainingEnrolments(result, enrolments, "Propedeuticas");
        }
        enrolments.clear();

        enrolments.addAll(request.getExternalEnrolments());
        if (!enrolments.isEmpty()) {
            reportRemainingEnrolments(result, enrolments, "Externas");
        }

        result.append(generateEndLine());
    }

    return result.toString();
}
 

@Override
public void clear() {
  // Clear each collection, to make previously returned collections empty.
  for (Collection<V> collection : map.values()) {
    collection.clear();
  }
  map.clear();
  totalSize = 0;
}
 

/**
 * Removes all values for the provided key.
 */

private void removeValuesForKey(Object key) {
  Collection<V> collection = Maps.safeRemove(map, key);
  if (collection != null) {
    int count = collection.size();
    collection.clear();
    totalSize -= count;
  }
        }
 

protected final void execFieldReader(final Object obj, ClassFieldDescription field) throws IllegalAccessException {
    Collection<AxisDescription> setVal = (Collection<AxisDescription>) field.getField().get(obj); // NOPMD
    // N.B. cast should fail at runtime (points to lib inconsistency)
    setVal.clear();
    final int nElements = ioBuffer.getInt(); // number of elements
    for (int i = 0; i < nElements; i++) {
        // read start marker
        BinarySerialiser.getFieldHeader(ioBuffer);
        final byte startMarker = ioBuffer.getByte();
        if (startMarker != DataType.START_MARKER.getAsByte()) {
            throw new IllegalStateException("corrupt start marker, value is " + startMarker + " vs. should "
                                            + DataType.START_MARKER.getAsByte());
        }

        BinarySerialiser.getFieldHeader(ioBuffer);
        String axisName = ioBuffer.getString();
        BinarySerialiser.getFieldHeader(ioBuffer);
        String axisUnit = ioBuffer.getString();
        BinarySerialiser.getFieldHeader(ioBuffer);
        double min = ioBuffer.getDouble();
        BinarySerialiser.getFieldHeader(ioBuffer);
        double max = ioBuffer.getDouble();

        DefaultAxisDescription ad = new DefaultAxisDescription(null, axisName, axisUnit, min, max); // NOPMD
        // N.B. PMD - unavoidable in-loop instantiation

        BinarySerialiser.getFieldHeader(ioBuffer);
        final byte endMarker = ioBuffer.getByte();
        if (endMarker != DataType.END_MARKER.getAsByte()) {
            throw new IllegalStateException(
                    "corrupt end marker, value is " + endMarker + " vs. should " + DataType.END_MARKER.getAsByte());
        }

        setVal.add(ad);
    }

    field.getField().set(obj, setVal);
}
 

@Override
public Collection<V> remove(Object key) {
  Collection<V> collection = submap.remove(key);
  if (collection == null) {
    return null;
  }
  Collection<V> output = createCollection();
  output.addAll(collection);
  totalSize -= collection.size();
  collection.clear();
  return output;
}
 

public synchronized void clear() {
    parentIndexFieldData = null;
    List<Throwable> exceptions = new ArrayList<>(0);
    final Collection<IndexFieldDataCache> fieldDataCacheValues = fieldDataCaches.values();
    for (IndexFieldDataCache cache : fieldDataCacheValues) {
        try {
            cache.clear();
        } catch (Throwable t) {
            exceptions.add(t);
        }
    }
    fieldDataCacheValues.clear();
    ExceptionsHelper.maybeThrowRuntimeAndSuppress(exceptions);
}
 

@Override
public Iterator<K> iterator() {
  final Iterator<Map.Entry<K, Collection<V>>> entryIterator = map().entrySet().iterator();
  return new Iterator<K>() {
    Map.Entry<K, Collection<V>> entry;

    @Override
    public boolean hasNext() {
      return entryIterator.hasNext();
    }

    @Override
    public K next() {
      entry = entryIterator.next();
      return entry.getKey();
    }

    @Override
    public void remove() {
      checkRemove(entry != null);
      Collection<V> collection = entry.getValue();
      entryIterator.remove();
      totalSize -= collection.size();
      collection.clear();
    }
  };
}
 

private void getOracleGroundings(final Collection<VariableParam> ungroundParamsInEvaluablePrecondition, final Queue<Literal> literalsOrderedByOracability, final Monom state, final Set<VariableParam> paramsGroundSoFar,
		final Collection<Map<VariableParam, ConstantParam>> groundingsFixedSoFar, final Map<VariableParam, ConstantParam> basicConstantGrounding) {
	if (literalsOrderedByOracability.isEmpty()) {
		return;
	}

	Literal l = literalsOrderedByOracability.poll();

	/* check whether the literal only needs to be queried for one param */
	Collection<LiteralParam> paramsThatNeedGrounding = SetUtil.intersection(SetUtil.difference(ungroundParamsInEvaluablePrecondition, paramsGroundSoFar), l.getParameters());
	logger.info("Now checking validity of {}. Set of params that still need grounding: {}", l, paramsThatNeedGrounding);
	if (paramsThatNeedGrounding.size() > 1) {
		throw new UnsupportedOperationException("Currently only support for at most one unground variable! Here, the following variables of \"" + l + "\"need grounding: " + paramsThatNeedGrounding);
	}

	/* now go over all previous groundings and check them */
	List<Map<VariableParam, ConstantParam>> localCopyOfCurrentGrounding = new ArrayList<>(groundingsFixedSoFar);
	VariableParam paramToBeGround = null;

	/* create an array with the parameters of the literal defined by the basic grounding, and determine the one to be oracled */
	ConstantParam[] params = new ConstantParam[l.getParameters().size()];
	int indexOfParam = -1;
	Map<VariableParam, Integer> positionsOfVariableParams = new HashMap<>();
	for (int i = 0; i < params.length; i++) {
		LiteralParam param = l.getParameters().get(i);
		boolean parameterIsConstant = param instanceof ConstantParam;
		boolean parameterIsGround = basicConstantGrounding.containsKey(param);
		boolean parameterHasBeenDecidedByOracle = !(parameterIsConstant || parameterIsGround) && paramsGroundSoFar.contains(param);
		if (parameterIsConstant) {
			params[i] = (ConstantParam) param;
		} else if (parameterIsGround) {
			params[i] = basicConstantGrounding.get(param);
		} else {
			positionsOfVariableParams.put((VariableParam) param, i);
			if (!parameterHasBeenDecidedByOracle) {
				indexOfParam = i;
				paramToBeGround = (VariableParam) l.getParameters().get(i);
			}
		}
	}

	/* update list of solutions */
	groundingsFixedSoFar.clear();
	for (Map<VariableParam, ConstantParam> previouslyOracledGrounding : localCopyOfCurrentGrounding) {

		logger.info("Considering combination of previously fixed oracle decisions: {}", previouslyOracledGrounding);

		/* completing the param array */
		for (VariableParam oracledParam : paramsGroundSoFar) {
			if (!positionsOfVariableParams.containsKey(oracledParam)) {
				logger.debug("Ignoring ground value {} of param {}, because this param does not occur in the literal", previouslyOracledGrounding.get(oracledParam), oracledParam);
				continue;
			}
			logger.debug("Inserting {} at position {} in the param array.", previouslyOracledGrounding.get(oracledParam), positionsOfVariableParams.get(oracledParam));
			params[positionsOfVariableParams.get(oracledParam)] = previouslyOracledGrounding.get(oracledParam);
		}
		if (logger.isInfoEnabled()) {
			logger.info("Params for literal are {}", Arrays.toString(params));
		}

		/* recover the parameter to ground */
		final int finalizedIndexOfParam = indexOfParam;
		if ((finalizedIndexOfParam >= 0) != (paramToBeGround != null)) {
			throw new IllegalStateException("Param to be ground is " + paramToBeGround + ", but the index in the literal is " + finalizedIndexOfParam);
		}

		/* determine currently valid candidates */
		EvaluablePredicate predicate = this.evaluablePlanningPredicates.get(l.getPropertyName());

		/* if this param is checked for the first time, aquire an oracle */
		if (paramToBeGround != null) {
			logger.info("No valid grounding for param {} are known, so apply oracle.", paramToBeGround);
			Collection<List<ConstantParam>> possibleGroundingsOfThisPredicate = l.isPositive() ? predicate.getParamsForPositiveEvaluation(state, params) : predicate.getParamsForNegativeEvaluation(state, params);
			if (possibleGroundingsOfThisPredicate == null) {
				logger.warn("Predicate {} returned NULL for params {} in state {}. Canceling grounding process.", l.getPropertyName(), params, state);
				return;
			}
			Collection<ConstantParam> possibleValuesForNewParamInThisGrounding = possibleGroundingsOfThisPredicate.stream().map(s -> s.get(finalizedIndexOfParam)).collect(Collectors.toSet());
			for (ConstantParam oracledParamOfThisLiteral : possibleValuesForNewParamInThisGrounding) {
				Map<VariableParam, ConstantParam> extendedOracleGrounding = new HashMap<>(previouslyOracledGrounding);
				extendedOracleGrounding.put(paramToBeGround, oracledParamOfThisLiteral);
				groundingsFixedSoFar.add(extendedOracleGrounding);
			}
			logger.info("Candidates for grounding is now {}", groundingsFixedSoFar);
			paramsGroundSoFar.add(paramToBeGround);
		}

		/* otherwise just test the predicate against the choices already made */
		else {
			if (logger.isInfoEnabled()) {
				logger.info("No new parameters to ground. Only testing {} (evaluated by {}) against params {} given groundings {}.", l, predicate.getClass().getName(), Arrays.toString(params), groundingsFixedSoFar);
			}
			localCopyOfCurrentGrounding.stream().filter(grounding -> predicate.test(state, params) == l.isPositive()).forEach(groundingsFixedSoFar::add);
		}
	}
	logger.info("Proceeding with extended oracle grounding: {}", groundingsFixedSoFar);
	this.getOracleGroundings(ungroundParamsInEvaluablePrecondition, literalsOrderedByOracability, state, paramsGroundSoFar, groundingsFixedSoFar, basicConstantGrounding);
}
 

@Override
public void removeAllRolesFromUser(User user) {
    Collection<Role> userRoles = this.userRoles.computeIfAbsent(user, u -> new ArrayList<>(server.getRoles(u)));
    userRoles.clear();
}
 

/**
 * Tries to release many memory segments together.
 *
 * <p>If the memory manager manages pre-allocated memory, the memory segment goes back to the memory pool.
 * Otherwise, the segment is only freed and made eligible for reclamation by the GC.
 *
 * @param segments The segments to be released.
 * @throws NullPointerException Thrown, if the given collection is null.
 * @throws IllegalArgumentException Thrown, id the segments are of an incompatible type.
 */
public void release(Collection<MemorySegment> segments) {
	if (segments == null) {
		return;
	}

	// -------------------- BEGIN CRITICAL SECTION -------------------
	synchronized (lock) {
		if (isShutDown) {
			throw new IllegalStateException("Memory manager has been shut down.");
		}

		// since concurrent modifications to the collection
		// can disturb the release, we need to try potentially multiple times
		boolean successfullyReleased = false;
		do {
			final Iterator<MemorySegment> segmentsIterator = segments.iterator();

			Object lastOwner = null;
			Set<MemorySegment> segsForOwner = null;

			try {
				// go over all segments
				while (segmentsIterator.hasNext()) {

					final MemorySegment seg = segmentsIterator.next();
					if (seg == null || seg.isFreed()) {
						continue;
					}

					final Object owner = seg.getOwner();

					try {
						// get the list of segments by this owner only if it is a different owner than for
						// the previous one (or it is the first segment)
						if (lastOwner != owner) {
							lastOwner = owner;
							segsForOwner = this.allocatedSegments.get(owner);
						}

						// remove the segment from the list
						if (segsForOwner != null) {
							segsForOwner.remove(seg);
							if (segsForOwner.isEmpty()) {
								this.allocatedSegments.remove(owner);
							}
						}

						if (isPreAllocated) {
							memoryPool.returnSegmentToPool(seg);
						}
						else {
							seg.free();
							numNonAllocatedPages++;
						}
					}
					catch (Throwable t) {
						throw new RuntimeException(
								"Error removing book-keeping reference to allocated memory segment.", t);
					}
				}

				segments.clear();

				// the only way to exit the loop
				successfullyReleased = true;
			}
			catch (ConcurrentModificationException | NoSuchElementException e) {
				// this may happen in the case where an asynchronous
				// call releases the memory. fall through the loop and try again
			}
		} while (!successfullyReleased);
	}
	// -------------------- END CRITICAL SECTION -------------------
}
 

@SuppressWarnings("unchecked")
public void removeDuplicated(Collection list) {
    HashSet set = new HashSet(list);
    list.clear();
    list.addAll(set);
}
 

@Test
public void testGraphAccess() {
    Graph g = getGraph();
    
    TestOp<String, Integer> op = new TestOp<>();

    Vertex<TestOp<String, Integer>, String, Integer> v = g.insert(op, 1, 1);
    assertNotNull(v);
    assertSame(op, v.getInstance());

    Collection<Vertex<? extends Oplet<?, ?>, ?, ?>> c = getGraph().getVertices();
    assertNotNull(c);

    assertFalse(c.isEmpty());
    assertEquals(1, c.size());

    assertSame(v, c.toArray()[0]);
    
    assertTrue(getGraph().getEdges().isEmpty());

    try {
        c.clear();
        fail("Was able to modify graph collection");
    } catch (UnsupportedOperationException e) {
        // ok - expected
    }
    
    
    TestOp<Integer, Void> op2 = new TestOp<>();
    Vertex<TestOp<Integer, Void>, Integer, Void> v2 = g.insert(op2, 1, 0);
    
    c = getGraph().getVertices();
    assertNotNull(c);

    assertFalse(c.isEmpty());
    assertEquals(2, c.size());

    assertSame(v, c.toArray()[0]);
    assertSame(v2, c.toArray()[1]);
    
    assertTrue(getGraph().getEdges().isEmpty());
    
    v.getConnectors().get(0).connect(v2, 0);
    
    Collection<Edge> edges = getGraph().getEdges();
    assertFalse(edges.isEmpty());
    assertEquals(1, edges.size());
    
    Edge vtov2 = (Edge) edges.toArray()[0];
    assertSame(v, vtov2.getSource());
    assertEquals(0, vtov2.getSourceOutputPort());
    
    assertSame(v2, vtov2.getTarget());
    assertEquals(0, vtov2.getTargetInputPort());
}