| /** |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you 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.apache.crunch; |
| |
| import java.io.Serializable; |
| |
| import com.google.common.collect.ComparisonChain; |
| import com.google.common.collect.Ordering; |
| import org.apache.commons.lang.builder.HashCodeBuilder; |
| |
| /** |
| * A convenience class for two-element {@link Tuple}s. |
| */ |
| public class Pair<K, V> implements Tuple, Comparable<Pair<K, V>>, Serializable { |
| |
| private final K first; |
| private final V second; |
| |
| public static <T, U> Pair<T, U> of(T first, U second) { |
| return new Pair<T, U>(first, second); |
| } |
| |
| public Pair(K first, V second) { |
| this.first = first; |
| this.second = second; |
| } |
| |
| public K first() { |
| return first; |
| } |
| |
| public V second() { |
| return second; |
| } |
| |
| public Object get(int index) { |
| switch (index) { |
| case 0: |
| return first; |
| case 1: |
| return second; |
| default: |
| throw new ArrayIndexOutOfBoundsException(); |
| } |
| } |
| |
| public int size() { |
| return 2; |
| } |
| |
| @Override |
| public int hashCode() { |
| HashCodeBuilder hcb = new HashCodeBuilder(); |
| return hcb.append(first).append(second).toHashCode(); |
| } |
| |
| @Override |
| public boolean equals(Object obj) { |
| if (this == obj) |
| return true; |
| if (obj == null) |
| return false; |
| if (getClass() != obj.getClass()) |
| return false; |
| Pair<?, ?> other = (Pair<?, ?>) obj; |
| return (first == other.first || (first != null && first.equals(other.first))) |
| && (second == other.second || (second != null && second.equals(other.second))); |
| } |
| |
| @Override |
| public String toString() { |
| StringBuilder sb = new StringBuilder("["); |
| sb.append(first).append(",").append(second).append("]"); |
| return sb.toString(); |
| } |
| |
| private int cmp(Object lhs, Object rhs) { |
| if (lhs == rhs) { |
| return 0; |
| } else if (lhs != null && Comparable.class.isAssignableFrom(lhs.getClass())) { |
| return Ordering.natural().nullsLast().compare((Comparable) lhs, (Comparable) rhs);//(Comparable) lhs).compareTo(rhs); |
| } |
| if (lhs == null) { |
| return 1; // nulls last |
| } |
| if (rhs == null) { |
| return -1; // nulls last |
| } |
| if (lhs.equals(rhs)) { |
| return 0; |
| } |
| |
| // Now we compare based on hash code. We already know that the two sides are not equal, so |
| // if the hash codes are equal, we just use arbitrary (but consistent) ordering |
| return ComparisonChain.start() |
| .compare(lhs.hashCode(), rhs.hashCode()) |
| .compare(lhs, rhs, Ordering.arbitrary()) |
| .result(); |
| } |
| |
| @Override |
| public int compareTo(Pair<K, V> o) { |
| int diff = cmp(first, o.first); |
| if (diff == 0) { |
| diff = cmp(second, o.second); |
| } |
| return diff; |
| } |
| } |