org.apache.hadoop.hdfs

类 DFSClient.DFSInputStream

java.lang.Object

java.io.InputStream

org.apache.hadoop.fs.FSInputStream

org.apache.hadoop.hdfs.DFSClient.DFSInputStream

所有已实现的接口:

Closeable, AutoCloseable, PositionedReadable, Seekable

封闭类:

DFSClient

public class DFSClient.DFSInputStream
extends FSInputStream

DFSInputStream provides bytes from a named file. It handles negotiation of the namenode and various datanodes as necessary.

方法概要

方法

限定符和类型	方法和说明
int	available()
void	close() Close it down!
Block	getCurrentBlock() Returns the block containing the target position.
DatanodeInfo	getCurrentDatanode() Returns the datanode from which the stream is currently reading.
long	getFileLength()
long	getPos() Return the current offset from the start of the file
void	mark(int readLimit)
boolean	markSupported() We definitely don't support marks
int	read()
int	read(byte[] buf, int off, int len) Read the entire buffer.
int	read(long position, byte[] buffer, int offset, int length) Read bytes starting from the specified position.
void	reset()
void	seek(long targetPos) Seek to a new arbitrary location
boolean	seekToNewSource(long targetPos) Seek to given position on a node other than the current node.
long	skip(long n)

从类继承的方法 org.apache.hadoop.fs.FSInputStream

readFully, readFully

从类继承的方法 java.io.InputStream

read

从类继承的方法 java.lang.Object

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

方法详细资料

getFileLength

public long getFileLength()

getCurrentDatanode

public DatanodeInfo getCurrentDatanode()

Returns the datanode from which the stream is currently reading.

getCurrentBlock

public Block getCurrentBlock()

Returns the block containing the target position.

close

public void close()
           throws IOException

Close it down!

指定者:

close 在接口中 Closeable

指定者:

close 在接口中 AutoCloseable

覆盖:

close 在类中 InputStream

抛出:

IOException

read

public int read()
         throws IOException

指定者:

read 在类中 InputStream

抛出:

IOException

read

public int read(byte[] buf,
       int off,
       int len)
         throws IOException

Read the entire buffer.

覆盖:

read 在类中 InputStream

抛出:

IOException

read

public int read(long position,
       byte[] buffer,
       int offset,
       int length)
         throws IOException

Read bytes starting from the specified position.

指定者:

read 在接口中 PositionedReadable

覆盖:

read 在类中 FSInputStream

参数:

position - start read from this position

buffer - read buffer

offset - offset into buffer

length - number of bytes to read

返回:

actual number of bytes read

抛出:

IOException

skip

public long skip(long n)
          throws IOException

覆盖:

skip 在类中 InputStream

抛出:

IOException

seek

public void seek(long targetPos)
          throws IOException

Seek to a new arbitrary location

指定者:

seek 在接口中 Seekable

指定者:

seek 在类中 FSInputStream

抛出:

IOException

seekToNewSource

public boolean seekToNewSource(long targetPos)
                        throws IOException

Seek to given position on a node other than the current node. If a node other than the current node is found, then returns true. If another node could not be found, then returns false.

指定者:

seekToNewSource 在接口中 Seekable

指定者:

seekToNewSource 在类中 FSInputStream

抛出:

IOException

getPos

public long getPos()
            throws IOException

从类复制的说明: FSInputStream

Return the current offset from the start of the file

指定者:

getPos 在接口中 Seekable

指定者:

getPos 在类中 FSInputStream

抛出:

IOException

available

public int available()
              throws IOException

覆盖:

available 在类中 InputStream

抛出:

IOException

markSupported

public boolean markSupported()

We definitely don't support marks

覆盖:

markSupported 在类中 InputStream

mark

public void mark(int readLimit)

覆盖:

mark 在类中 InputStream

reset

public void reset()
           throws IOException

覆盖:

reset 在类中 InputStream

抛出:

IOException