Java tutorial
/* * Copyright 2008-present MongoDB, Inc. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package com.mongodb; import com.mongodb.annotations.Immutable; import java.util.ArrayList; import java.util.Collections; import java.util.Comparator; import java.util.HashSet; import java.util.Iterator; import java.util.List; import java.util.Set; import static com.mongodb.assertions.Assertions.notNull; /** * An immutable set of tags, used to select members of a replica set to use for read operations. * * @mongodb.driver.manual tutorial/configure-replica-set-tag-sets Tag Sets * @see com.mongodb.ReadPreference * @since 2.13 */ @Immutable public final class TagSet implements Iterable<Tag> { private final List<Tag> wrapped; /** * An empty set of tags. */ public TagSet() { wrapped = Collections.emptyList(); } /** * A set of tags contain the single given tag * * @param tag the tag */ public TagSet(final Tag tag) { notNull("tag", tag); wrapped = Collections.singletonList(tag); } /** * A set of tags containing the given list of tags. * * @param tagList the list of tags */ public TagSet(final List<Tag> tagList) { notNull("tagList", tagList); // Ensure no duplicates Set<String> tagNames = new HashSet<String>(); for (Tag tag : tagList) { if (tag == null) { throw new IllegalArgumentException("Null tags are not allowed"); } if (!tagNames.add(tag.getName())) { throw new IllegalArgumentException( "Duplicate tag names not allowed in a tag set: " + tag.getName()); } } ArrayList<Tag> copy = new ArrayList<Tag>(tagList); Collections.sort(copy, new Comparator<Tag>() { @Override public int compare(final Tag o1, final Tag o2) { return o1.getName().compareTo(o2.getName()); } }); this.wrapped = Collections.unmodifiableList(copy); } @Override public Iterator<Tag> iterator() { return wrapped.iterator(); } /** * Returns {@code true} if this tag set contains all of the elements of the specified tag set. * * @param tagSet tag set to be checked for containment in this tag set * @return {@code true} if this tag set contains all of the elements of the specified tag set */ public boolean containsAll(final TagSet tagSet) { return wrapped.containsAll(tagSet.wrapped); } @Override public boolean equals(final Object o) { if (this == o) { return true; } if (o == null || getClass() != o.getClass()) { return false; } final TagSet tags = (TagSet) o; if (!wrapped.equals(tags.wrapped)) { return false; } return true; } @Override public int hashCode() { return wrapped.hashCode(); } @Override public String toString() { return "TagSet{" + wrapped + '}'; } }