Package org.apache.hadoop.fs

Class FSDataOutputStream

java.lang.Object

java.io.OutputStream

java.io.FilterOutputStream

java.io.DataOutputStream

org.apache.hadoop.fs.FSDataOutputStream

All Implemented Interfaces:

Closeable, DataOutput, Flushable, AutoCloseable, Abortable, CanSetDropBehind, org.apache.hadoop.fs.statistics.IOStatisticsSource, StreamCapabilities, Syncable

Direct Known Subclasses:

HdfsDataOutputStream

@Public
@Stable
public class FSDataOutputStream
extends DataOutputStream
implements Syncable, CanSetDropBehind, StreamCapabilities, org.apache.hadoop.fs.statistics.IOStatisticsSource, Abortable

Utility that wraps a OutputStream in a DataOutputStream.

Nested Class Summary

Nested classes/interfaces inherited from interface org.apache.hadoop.fs.Abortable

org.apache.hadoop.fs.Abortable.AbortableResult

Nested classes/interfaces inherited from interface org.apache.hadoop.fs.StreamCapabilities

StreamCapabilities.StreamCapability

Field Summary

Fields inherited from class java.io.DataOutputStream

written

Fields inherited from class java.io.FilterOutputStream

out

Fields inherited from interface org.apache.hadoop.fs.StreamCapabilities

ABORTABLE_STREAM, DROPBEHIND, HFLUSH, HSYNC, IOSTATISTICS, IOSTATISTICS_CONTEXT, PREADBYTEBUFFER, READAHEAD, READBYTEBUFFER, UNBUFFER, VECTOREDIO, VECTOREDIO_BUFFERS_SLICED

Constructor Summary

Constructors

Constructor	Description
FSDataOutputStream(OutputStream out, org.apache.hadoop.fs.FileSystem.Statistics stats)
FSDataOutputStream(OutputStream out, org.apache.hadoop.fs.FileSystem.Statistics stats, long startPosition)

Method Summary

Modifier and Type	Method	Description
org.apache.hadoop.fs.Abortable.AbortableResult	abort()	Invoke abort() on the wrapped stream if it is Abortable, otherwise raise an UnsupportedOperationException.
void	close()	Close the underlying output stream.
IOStatistics	getIOStatistics()	Get the IO Statistics of the nested stream, falling back to empty statistics if the stream does not implement the interface IOStatisticsSource.
long	getPos()	Get the current position in the output stream.
OutputStream	getWrappedStream()	Get a reference to the wrapped output stream.
boolean	hasCapability(String capability)	Query the stream for a specific capability.
void	hflush()	Flush out the data in client's user buffer.
void	hsync()	Similar to posix fsync, flush out the data in client's user buffer all the way to the disk device (but the disk may have it in its cache).
void	setDropBehind(Boolean dropBehind)	Configure whether the stream should drop the cache.
String	toString()

Methods inherited from class java.io.DataOutputStream

flush, size, write, write, writeBoolean, writeByte, writeBytes, writeChar, writeChars, writeDouble, writeFloat, writeInt, writeLong, writeShort, writeUTF

Methods inherited from class java.io.FilterOutputStream

write

Methods inherited from class java.io.OutputStream

nullOutputStream

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.io.DataOutput

write

Constructor Details

FSDataOutputStream

public FSDataOutputStream(OutputStream out,
 org.apache.hadoop.fs.FileSystem.Statistics stats)

FSDataOutputStream

public FSDataOutputStream(OutputStream out,
 org.apache.hadoop.fs.FileSystem.Statistics stats,
 long startPosition)

Method Details

getPos

public long getPos()

Get the current position in the output stream.

Returns:

the current position in the output stream

close

public void close()
           throws IOException

Close the underlying output stream.

Specified by:

close in interface AutoCloseable

Specified by:

close in interface Closeable

Overrides:

close in class FilterOutputStream

Throws:

IOException

toString

public String toString()

Overrides:

toString in class Object

getWrappedStream

@LimitedPrivate("HDFS")
public OutputStream getWrappedStream()

Get a reference to the wrapped output stream.

Returns:

the underlying output stream

hasCapability

public boolean hasCapability(String capability)

Description copied from interface: StreamCapabilities

Query the stream for a specific capability.

Specified by:

hasCapability in interface StreamCapabilities

Parameters:

capability - string to query the stream support for.

Returns:

True if the stream supports capability.

hflush

public void hflush()
            throws IOException

Description copied from interface: Syncable

Flush out the data in client's user buffer. After the return of this call, new readers will see the data.

Specified by:

hflush in interface Syncable

Throws:

IOException - if any error occurs

hsync

public void hsync()
           throws IOException

Description copied from interface: Syncable

Similar to posix fsync, flush out the data in client's user buffer all the way to the disk device (but the disk may have it in its cache).

Specified by:

hsync in interface Syncable

Throws:

IOException - if error occurs

setDropBehind

public void setDropBehind(Boolean dropBehind)
                   throws IOException

Description copied from interface: CanSetDropBehind

Configure whether the stream should drop the cache.

Specified by:

setDropBehind in interface CanSetDropBehind

Parameters:

dropBehind - Whether to drop the cache. null means to use the default value.

Throws:

IOException - If there was an error changing the dropBehind setting. UnsupportedOperationException If this stream doesn't support setting the drop-behind.

getIOStatistics

public IOStatistics getIOStatistics()

Get the IO Statistics of the nested stream, falling back to empty statistics if the stream does not implement the interface IOStatisticsSource.

Specified by:

getIOStatistics in interface org.apache.hadoop.fs.statistics.IOStatisticsSource

Returns:

an IOStatistics instance.

abort

public org.apache.hadoop.fs.Abortable.AbortableResult abort()

Invoke abort() on the wrapped stream if it is Abortable, otherwise raise an UnsupportedOperationException.

Specified by:

abort in interface Abortable

Returns:

the result.

Throws:

UnsupportedOperationException - if not available.