程序包 org.apache.hadoop.mapred.lib.aggregate
的使用

使用org.apache.hadoop.mapred.lib.aggregate的程序包

程序包	说明
org.apache.hadoop.examples	Hadoop example code.
org.apache.hadoop.mapred.lib.aggregate	Classes for performing various counting and aggregations.

org.apache.hadoop.examples使用的org.apache.hadoop.mapred.lib.aggregate中的类

类和说明
ValueAggregatorBaseDescriptor This class implements the common functionalities of the subclasses of ValueAggregatorDescriptor class.
ValueAggregatorDescriptor This interface defines the contract a value aggregator descriptor must support.

org.apache.hadoop.mapred.lib.aggregate使用的org.apache.hadoop.mapred.lib.aggregate中的类

类和说明
ValueAggregator This interface defines the minimal protocol for value aggregators.
ValueAggregatorDescriptor This interface defines the contract a value aggregator descriptor must support.
ValueAggregatorJobBase This abstract class implements some common functionalities of the the generic mapper, reducer and combiner classes of Aggregate.