Java tutorial
// Copyright 2017 JanusGraph Authors // // 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 org.janusgraph.util.datastructures; import com.google.common.base.Preconditions; import com.google.common.base.Predicate; import com.google.common.collect.Iterables; import com.google.common.collect.Sets; import org.apache.commons.collections.comparators.ComparableComparator; import org.apache.commons.lang.builder.HashCodeBuilder; import javax.annotation.Nullable; import java.util.*; /** * @author Matthias Broecheler (me@matthiasb.com) */ public class PointInterval<T> implements Interval<T> { private final Set<T> points; private PointInterval(Set<T> points) { this.points = points; } public PointInterval(T point) { points = new HashSet<T>(1); points.add(point); } public PointInterval(T... points) { this(Arrays.asList(points)); } public PointInterval(Iterable<T> points) { this.points = new HashSet<T>(4); Iterables.addAll(this.points, points); } @Override public Collection<T> getPoints() { return points; } public void setPoint(T point) { points.clear(); points.add(point); } public void addPoint(T point) { points.add(point); } @Override public T getStart() { Preconditions.checkArgument(!isEmpty(), "There are no points in this interval"); return (T) Collections.min(points, ComparableComparator.getInstance()); } @Override public T getEnd() { Preconditions.checkArgument(!isEmpty(), "There are no points in this interval"); return (T) Collections.max(points, ComparableComparator.getInstance()); } @Override public boolean startInclusive() { return true; } @Override public boolean endInclusive() { return true; } @Override public boolean isPoints() { return true; } @Override public boolean isEmpty() { return points.isEmpty(); } @Override public Interval<T> intersect(Interval<T> other) { Preconditions.checkArgument(other != null); if (other instanceof PointInterval) { Set<T> merge = Sets.newHashSet(points); points.retainAll(((PointInterval) other).points); return new PointInterval<T>(points); } else if (other instanceof RangeInterval) { final RangeInterval<T> rint = (RangeInterval) other; return new PointInterval<T>(Sets.newHashSet(Iterables.filter(points, new Predicate<T>() { @Override public boolean apply(@Nullable T t) { return rint.containsPoint(t); } }))); } else throw new AssertionError("Unexpected interval: " + other); } @Override public int hashCode() { return points.hashCode(); } @Override public boolean equals(Object other) { if (this == other) return true; else if (other == null) return false; else if (!getClass().isInstance(other)) return false; PointInterval oth = (PointInterval) other; return points.equals(oth.points); } @Override public String toString() { StringBuilder s = new StringBuilder(); s.append("["); int i = 0; for (T point : points) { if (i > 0) s.append(","); s.append(point); i++; } s.append("]"); return s.toString(); } }