/** * Copyright 2005 The Apache Software Foundation * * 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.apache.hadoop.io;import java.io.*;/** A WritableComparable for longs. */public class LongWritable implements WritableComparable {  private long value;  public LongWritable() {}  public LongWritable(long value) { set(value); }  /** Set the value of this LongWritable. */  public void set(long value) { this.value = value; }  /** Return the value of this LongWritable. */  public long get() { return value; }  public void readFields(DataInput in) throws IOException {    value = in.readLong();  }  public void write(DataOutput out) throws IOException {    out.writeLong(value);  }  /** Returns true iff <code>o</code> is a LongWritable with the same value. */  public boolean equals(Object o) {    if (!(o instanceof LongWritable))      return false;    LongWritable other = (LongWritable)o;    return this.value == other.value;  }  public int hashCode() {    return (int)value;  }  /** Compares two LongWritables. */  public int compareTo(Object o) {    long thisValue = this.value;    long thatValue = ((LongWritable)o).value;    return (thisValue<thatValue ? -1 : (thisValue==thatValue ? 0 : 1));  }  public String toString() {    return Long.toString(value);  }  /** A Comparator optimized for LongWritable. */   public static class Comparator extends WritableComparator {    public Comparator() {      super(LongWritable.class);    }    public int compare(byte[] b1, int s1, int l1,                       byte[] b2, int s2, int l2) {      long thisValue = readLong(b1, s1);      long thatValue = readLong(b2, s2);      return (thisValue<thatValue ? -1 : (thisValue==thatValue ? 0 : 1));    }  }  /** A decreasing Comparator optimized for LongWritable. */   public static class DecreasingComparator extends Comparator {    public int compare(WritableComparable a, WritableComparable b) {      return -super.compare(a, b);    }    public int compare(byte[] b1, int s1, int l1, byte[] b2, int s2, int l2) {      return -super.compare(b1, s1, l1, b2, s2, l2);    }  }  static {                                       // register default comparator    WritableComparator.define(LongWritable.class, new Comparator());  }}