org.apache.hadoop.io

类 SequenceFile.Writer

java.lang.Object

org.apache.hadoop.io.SequenceFile.Writer

所有已实现的接口:

Closeable, AutoCloseable

封闭类:

SequenceFile

public static class SequenceFile.Writer
extends Object
implements Closeable

Write key/value pairs to a sequence-format file.

字段概要

字段

限定符和类型	字段和说明
protected Serializer	compressedValSerializer
protected Serializer	keySerializer
protected Serializer	uncompressedValSerializer

构造器概要

构造器

构造器和说明
SequenceFile.Writer(FileSystem fs, Configuration conf, Path name, Class keyClass, Class valClass) Create the named file.
SequenceFile.Writer(FileSystem fs, Configuration conf, Path name, Class keyClass, Class valClass, int bufferSize, short replication, long blockSize, Progressable progress, SequenceFile.Metadata metadata) Create the named file with write-progress reporter.
SequenceFile.Writer(FileSystem fs, Configuration conf, Path name, Class keyClass, Class valClass, Progressable progress, SequenceFile.Metadata metadata) Create the named file with write-progress reporter.

方法概要

方法

限定符和类型	方法和说明
void	append(Object key, Object val) Append a key/value pair.
void	append(Writable key, Writable val) Append a key/value pair.
void	appendRaw(byte[] keyData, int keyOffset, int keyLength, SequenceFile.ValueBytes val)
void	close() Close the file.
CompressionCodec	getCompressionCodec() Returns the compression codec of data in this file.
Class	getKeyClass() Returns the class of keys in this file.
long	getLength() Returns the current length of the output file.
Class	getValueClass() Returns the class of values in this file.
void	sync() create a sync point
void	syncFs() flush all currently written data to the file system

从类继承的方法 java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

字段详细资料

keySerializer

protected Serializer keySerializer

uncompressedValSerializer

protected Serializer uncompressedValSerializer

compressedValSerializer

protected Serializer compressedValSerializer

构造器详细资料

SequenceFile.Writer

public SequenceFile.Writer(FileSystem fs,
                   Configuration conf,
                   Path name,
                   Class keyClass,
                   Class valClass)
                    throws IOException

Create the named file.

抛出:

IOException

SequenceFile.Writer

public SequenceFile.Writer(FileSystem fs,
                   Configuration conf,
                   Path name,
                   Class keyClass,
                   Class valClass,
                   Progressable progress,
                   SequenceFile.Metadata metadata)
                    throws IOException

Create the named file with write-progress reporter.

抛出:

IOException

SequenceFile.Writer

public SequenceFile.Writer(FileSystem fs,
                   Configuration conf,
                   Path name,
                   Class keyClass,
                   Class valClass,
                   int bufferSize,
                   short replication,
                   long blockSize,
                   Progressable progress,
                   SequenceFile.Metadata metadata)
                    throws IOException

Create the named file with write-progress reporter.

抛出:

IOException

方法详细资料

getKeyClass

public Class getKeyClass()

Returns the class of keys in this file.

getValueClass

public Class getValueClass()

Returns the class of values in this file.

getCompressionCodec

public CompressionCodec getCompressionCodec()

Returns the compression codec of data in this file.

sync

public void sync()
          throws IOException

create a sync point

抛出:

IOException

syncFs

public void syncFs()
            throws IOException

flush all currently written data to the file system

抛出:

IOException

close

public void close()
           throws IOException

Close the file.

指定者:

close 在接口中 Closeable

指定者:

close 在接口中 AutoCloseable

抛出:

IOException

append

public void append(Writable key,
          Writable val)
            throws IOException

Append a key/value pair.

抛出:

IOException

append

public void append(Object key,
          Object val)
            throws IOException

Append a key/value pair.

抛出:

IOException

appendRaw

public void appendRaw(byte[] keyData,
             int keyOffset,
             int keyLength,
             SequenceFile.ValueBytes val)
               throws IOException

抛出:

IOException

getLength

public long getLength()
               throws IOException

Returns the current length of the output file.

This always returns a synchronized position. In other words, immediately after calling SequenceFile.Reader.seek(long) with a position returned by this method, SequenceFile.Reader.next(Writable) may be called. However the key may be earlier in the file than key last written when this method was called (e.g., with block-compression, it may be the first key in the block that was being written when this method was called).

抛出:

IOException