## org.apache.hadoop.mapreduce.lib.input
Class SequenceFileInputFilter<K,V>

    java.lang.Object
      org.apache.hadoop.mapreduce.InputFormat<K,V>
          org.apache.hadoop.mapreduce.lib.input.FileInputFormat<K,V>
              org.apache.hadoop.mapreduce.lib.input.SequenceFileInputFormat<K,V>
                  org.apache.hadoop.mapreduce.lib.input.SequenceFileInputFilter<K,V>

    @InterfaceAudience.Public
    @InterfaceStability.Stable
    public class SequenceFileInputFilter<K,V>

extends SequenceFileInputFormat<K,V>

A class that allows a map/red job to work on a sample of sequence files. The sample is decided by the filter class set by the job.

Nested Class Summary
`static interface` `SequenceFileInputFilter.Filter` filter interface
`static class` `SequenceFileInputFilter.FilterBase` base class for Filters
`static class` `SequenceFileInputFilter.MD5Filter` This class returns a set of records by examing the MD5 digest of its key against a filtering frequency f.
`static class` `SequenceFileInputFilter.PercentFilter` This class returns a percentage of records The percentage is determined by a filtering frequency f using the criteria record# % f == 0.
`static class` `SequenceFileInputFilter.RegexFilter` Records filter by matching key to regex

Nested classes/interfaces inherited from class org.apache.hadoop.mapreduce.lib.input.FileInputFormat
`FileInputFormat.Counter`

Field Summary
`static String` `FILTER_CLASS`
`static String` `FILTER_FREQUENCY`
`static String` `FILTER_REGEX`
`static org.apache.commons.logging.Log` `LOG`

Constructor Summary
`SequenceFileInputFilter()`

Method Summary
`RecordReader<K,V>` `createRecordReader(InputSplit split, TaskAttemptContext context)` Create a record reader for the given split
`static void` `setFilterClass(Job job, Class<?> filterClass)` set the filter class

Methods inherited from class org.apache.hadoop.mapreduce.lib.input.SequenceFileInputFormat
`getFormatMinSplitSize, listStatus`

Methods inherited from class org.apache.hadoop.mapreduce.lib.input.FileInputFormat
`addInputPath, addInputPaths, computeSplitSize, getBlockIndex, getInputPathFilter, getInputPaths, getMaxSplitSize, getMinSplitSize, getSplits, isSplitable, setInputPathFilter, setInputPaths, setInputPaths, setMaxInputSplitSize, setMinInputSplitSize`

Methods inherited from class java.lang.Object
`clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

Field Detail

### LOG

    public static final org.apache.commons.logging.Log LOG

### FILTER_CLASS

    public static final String FILTER_CLASS

See Also:
  Constant Field Values

### FILTER_FREQUENCY

    public static final String FILTER_FREQUENCY

See Also:
  Constant Field Values

### FILTER_REGEX

    public static final String FILTER_REGEX

See Also:
  Constant Field Values

Constructor Detail

### SequenceFileInputFilter

    public SequenceFileInputFilter()

Method Detail

### createRecordReader

    public RecordReader<K,V> createRecordReader(InputSplit split,
                                                TaskAttemptContext context)
                                         throws IOException

  Create a record reader for the given split

  Overrides:
    `createRecordReader` in class `SequenceFileInputFormat<K,V>`
  Parameters:
    `split` - file split
    `context` - the task-attempt context
  Returns:
    RecordReader
  Throws:
    `IOException`

### setFilterClass

    public static void setFilterClass(Job job,
                                      Class<?> filterClass)

  set the filter class

  Parameters:
    `job` - The job
    `filterClass` - filter class

Copyright © 2009 The Apache Software Foundation