org.apache.hadoop.io

类 SetFile.Reader

java.lang.Object

org.apache.hadoop.io.MapFile.Reader

org.apache.hadoop.io.SetFile.Reader

所有已实现的接口:

Closeable, AutoCloseable

封闭类:

SetFile

public static class SetFile.Reader
extends MapFile.Reader

Provide access to an existing set file.

构造器概要

构造器

构造器和说明
SetFile.Reader(FileSystem fs, String dirName, Configuration conf) Construct a set reader for the named set.
SetFile.Reader(FileSystem fs, String dirName, WritableComparator comparator, Configuration conf) Construct a set reader for the named set using the named comparator.

方法概要

方法

限定符和类型	方法和说明
WritableComparable	get(WritableComparable key) Read the matching key from a set into key.
boolean	next(WritableComparable key) Read the next key in a set into key.
boolean	seek(WritableComparable key) Positions the reader at the named key, or if none such exists, at the first entry after the named key.

从类继承的方法 org.apache.hadoop.io.MapFile.Reader

close, createDataFileReader, finalKey, get, getClosest, getClosest, getKeyClass, getValueClass, midKey, next, open, reset

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

SetFile.Reader

public SetFile.Reader(FileSystem fs,
              String dirName,
              Configuration conf)
               throws IOException

Construct a set reader for the named set.

抛出:

IOException

SetFile.Reader

public SetFile.Reader(FileSystem fs,
              String dirName,
              WritableComparator comparator,
              Configuration conf)
               throws IOException

Construct a set reader for the named set using the named comparator.

抛出:

IOException

方法详细资料

seek

public boolean seek(WritableComparable key)
             throws IOException

从类复制的说明: MapFile.Reader

Positions the reader at the named key, or if none such exists, at the first entry after the named key. Returns true iff the named key exists in this map.

覆盖:

seek 在类中 MapFile.Reader

抛出:

IOException

next

public boolean next(WritableComparable key)
             throws IOException

Read the next key in a set into key. Returns true if such a key exists and false when at the end of the set.

抛出:

IOException

get

public WritableComparable get(WritableComparable key)
                       throws IOException

Read the matching key from a set into key. Returns key, or null if no match exists.

抛出:

IOException