# Hierarchy For Package org.apache.nutch.hostdb

Package Hierarchies:

- All Packages

## Class Hierarchy

- java.lang.Object
  - org.apache.hadoop.conf.Configured (implements org.apache.hadoop.conf.Configurable)
    - org.apache.nutch.hostdb.ReadHostDb (implements org.apache.hadoop.util.Tool)
    - org.apache.nutch.hostdb.UpdateHostDb (implements org.apache.hadoop.util.Tool)
  - org.apache.nutch.hostdb.FetchOverdueCrawlDatumProcessor (implements org.apache.nutch.hostdb.CrawlDatumProcessor)
  - org.apache.nutch.hostdb.HostDatum (implements java.lang.Cloneable, org.apache.hadoop.io.Writable)
  - org.apache.hadoop.mapreduce.Mapper<KEYIN,​VALUEIN,​KEYOUT,​VALUEOUT>
    - org.apache.nutch.hostdb.UpdateHostDbMapper
  - org.apache.hadoop.mapreduce.Reducer<KEYIN,​VALUEIN,​KEYOUT,​VALUEOUT>
    - org.apache.nutch.hostdb.UpdateHostDbReducer
  - org.apache.nutch.hostdb.ResolverThread (implements java.lang.Runnable)

## Interface Hierarchy

- org.apache.nutch.hostdb.CrawlDatumProcessor