org.apache.hadoop.mapreduce.lib.reduce

类 LongSumReducer<KEY>

java.lang.Object

org.apache.hadoop.mapreduce.Reducer<KEY,LongWritable,KEY,LongWritable>

org.apache.hadoop.mapreduce.lib.reduce.LongSumReducer<KEY>

public class LongSumReducer<KEY>
extends Reducer<KEY,LongWritable,KEY,LongWritable>

嵌套类概要

从类继承的嵌套类/接口 org.apache.hadoop.mapreduce.Reducer

Reducer.Context

构造器概要

构造器

构造器和说明
LongSumReducer()

方法概要

方法

限定符和类型	方法和说明
void	reduce(KEY key, Iterable<LongWritable> values, Reducer.Context context) This method is called once for each key.

从类继承的方法 org.apache.hadoop.mapreduce.Reducer

cleanup, run, setup

从类继承的方法 java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

构造器详细资料

LongSumReducer

public LongSumReducer()

方法详细资料

reduce

public void reduce(KEY key,
          Iterable<LongWritable> values,
          Reducer.Context context)
            throws IOException,
                   InterruptedException

从类复制的说明: Reducer

This method is called once for each key. Most applications will define their reduce class by overriding this method. The default implementation is an identity function.

覆盖:

reduce 在类中 Reducer<KEY,LongWritable,KEY,LongWritable>

抛出:

IOException

InterruptedException