001/** 002 * Licensed to the Apache Software Foundation (ASF) under one 003 * or more contributor license agreements. See the NOTICE file 004 * distributed with this work for additional information 005 * regarding copyright ownership. The ASF licenses this file 006 * to you under the Apache License, Version 2.0 (the 007 * "License"); you may not use this file except in compliance 008 * with the License. You may obtain a copy of the License at 009 * 010 * http://www.apache.org/licenses/LICENSE-2.0 011 * 012 * Unless required by applicable law or agreed to in writing, software 013 * distributed under the License is distributed on an "AS IS" BASIS, 014 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 015 * See the License for the specific language governing permissions and 016 * limitations under the License. 017 */ 018 019package org.apache.hadoop.io; 020 021 022import java.io.DataInput; 023import java.io.DataOutput; 024import java.io.IOException; 025 026import org.apache.hadoop.classification.InterfaceAudience; 027import org.apache.hadoop.classification.InterfaceStability; 028 029/** A WritableComparable for ints. */ 030@InterfaceAudience.Public 031@InterfaceStability.Stable 032public class IntWritable implements WritableComparable<IntWritable> { 033 private int value; 034 035 public IntWritable() {} 036 037 public IntWritable(int value) { set(value); } 038 039 /** Set the value of this IntWritable. */ 040 public void set(int value) { this.value = value; } 041 042 /** Return the value of this IntWritable. */ 043 public int get() { return value; } 044 045 public void readFields(DataInput in) throws IOException { 046 value = in.readInt(); 047 } 048 049 public void write(DataOutput out) throws IOException { 050 out.writeInt(value); 051 } 052 053 /** Returns true iff <code>o</code> is a IntWritable with the same value. */ 054 @Override 055 public boolean equals(Object o) { 056 if (!(o instanceof IntWritable)) 057 return false; 058 IntWritable other = (IntWritable)o; 059 return this.value == other.value; 060 } 061 062 @Override 063 public int hashCode() { 064 return value; 065 } 066 067 /** Compares two IntWritables. */ 068 @Override 069 public int compareTo(IntWritable o) { 070 int thisValue = this.value; 071 int thatValue = o.value; 072 return (thisValue<thatValue ? -1 : (thisValue==thatValue ? 0 : 1)); 073 } 074 075 @Override 076 public String toString() { 077 return Integer.toString(value); 078 } 079 080 /** A Comparator optimized for IntWritable. */ 081 public static class Comparator extends WritableComparator { 082 public Comparator() { 083 super(IntWritable.class); 084 } 085 086 @Override 087 public int compare(byte[] b1, int s1, int l1, 088 byte[] b2, int s2, int l2) { 089 int thisValue = readInt(b1, s1); 090 int thatValue = readInt(b2, s2); 091 return (thisValue<thatValue ? -1 : (thisValue==thatValue ? 0 : 1)); 092 } 093 } 094 095 static { // register this comparator 096 WritableComparator.define(IntWritable.class, new Comparator()); 097 } 098} 099