Java tutorial
/* * Copyright 2014 Mark Cusack * * 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.alexholmes.hadooputils.sort; import org.apache.hadoop.io.ArrayWritable; import org.apache.hadoop.io.LongWritable; import org.apache.hadoop.io.Writable; import org.apache.hadoop.io.WritableComparable; public class LongArrayWritable extends ArrayWritable implements WritableComparable<LongArrayWritable> { public LongArrayWritable() { super(LongWritable.class); } public int compareTo(LongArrayWritable o) { Writable[] theseLongs = get(); Writable[] thoseLongs = o.get(); int len = Math.min(theseLongs.length, thoseLongs.length); for (int i = 0; i < len; i++) { LongWritable thisLong = (LongWritable) theseLongs[i]; LongWritable thatLong = (LongWritable) thoseLongs[i]; int comp = thisLong.compareTo(thatLong); if (comp != 0) { return comp; } } return 0; } public int hashCode() { final int prime = 31; int result = 1; String[] theseStrings = toStrings(); for (int i = 0; i < theseStrings.length; i++) { result = result * prime + theseStrings[i].hashCode(); } return result; } }