org.apache.hadoop.io

类 ArrayFile.Reader

java.lang.Object

org.apache.hadoop.io.MapFile.Reader

org.apache.hadoop.io.ArrayFile.Reader

所有已实现的接口:

Closeable, AutoCloseable

封闭类:

ArrayFile

public static class ArrayFile.Reader
extends MapFile.Reader

Provide access to an existing array file.

构造器概要

构造器

构造器和说明
ArrayFile.Reader(FileSystem fs, String file, Configuration conf) Construct an array reader for the named file.

方法概要

方法

限定符和类型	方法和说明
Writable	get(long n, Writable value) Return the nth value in the file.
long	key() Returns the key associated with the most recent call to seek(long), next(Writable), or get(long,Writable).
Writable	next(Writable value) Read and return the next value in the file.
void	seek(long n) Positions the reader before its nth value.

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, seek

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

ArrayFile.Reader

public ArrayFile.Reader(FileSystem fs,
                String file,
                Configuration conf)
                 throws IOException

Construct an array reader for the named file.

抛出:

IOException

方法详细资料

seek

public void seek(long n)
          throws IOException

Positions the reader before its nth value.

抛出:

IOException

next

public Writable next(Writable value)
              throws IOException

Read and return the next value in the file.

抛出:

IOException

key

public long key()
         throws IOException

Returns the key associated with the most recent call to seek(long), next(Writable), or get(long,Writable).

抛出:

IOException

get

public Writable get(long n,
           Writable value)
             throws IOException

Return the nth value in the file.

抛出:

IOException