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 @Override 046 public void readFields(DataInput in) throws IOException { 047 value = in.readInt(); 048 } 049 050 @Override 051 public void write(DataOutput out) throws IOException { 052 out.writeInt(value); 053 } 054 055 /** Returns true iff <code>o</code> is a IntWritable with the same value. */ 056 @Override 057 public boolean equals(Object o) { 058 if (!(o instanceof IntWritable)) 059 return false; 060 IntWritable other = (IntWritable)o; 061 return this.value == other.value; 062 } 063 064 @Override 065 public int hashCode() { 066 return value; 067 } 068 069 /** Compares two IntWritables. */ 070 @Override 071 public int compareTo(IntWritable o) { 072 int thisValue = this.value; 073 int thatValue = o.value; 074 return (thisValue<thatValue ? -1 : (thisValue==thatValue ? 0 : 1)); 075 } 076 077 @Override 078 public String toString() { 079 return Integer.toString(value); 080 } 081 082 /** A Comparator optimized for IntWritable. */ 083 public static class Comparator extends WritableComparator { 084 public Comparator() { 085 super(IntWritable.class); 086 } 087 088 @Override 089 public int compare(byte[] b1, int s1, int l1, 090 byte[] b2, int s2, int l2) { 091 int thisValue = readInt(b1, s1); 092 int thatValue = readInt(b2, s2); 093 return (thisValue<thatValue ? -1 : (thisValue==thatValue ? 0 : 1)); 094 } 095 } 096 097 static { // register this comparator 098 WritableComparator.define(IntWritable.class, new Comparator()); 099 } 100} 101