程序包org.apache.hadoop.mapreduce.lib.reduce的分层结构

程序包分层结构:

• 所有程序包

类分层结构

• java.lang.Object
  • org.apache.hadoop.mapreduce.Reducer<KEYIN,VALUEIN,KEYOUT,VALUEOUT>
    • org.apache.hadoop.mapreduce.lib.reduce.IntSumReducer<Key>
    • org.apache.hadoop.mapreduce.lib.reduce.LongSumReducer<KEY>