org.apache.hadoop.hdfs

类 ByteRangeInputStream

java.lang.Object

java.io.InputStream

org.apache.hadoop.fs.FSInputStream

org.apache.hadoop.hdfs.ByteRangeInputStream

所有已实现的接口:

Closeable, AutoCloseable, PositionedReadable, Seekable

public abstract class ByteRangeInputStream
extends FSInputStream

To support HTTP byte streams, a new connection to an HTTP server needs to be created each time. This class hides the complexity of those multiple connections from the client. Whenever seek() is called, a new connection is made on the successive read(). The normal input stream functions are connected to the currently active input stream.

嵌套类概要

嵌套类

限定符和类型	类和说明
static class	ByteRangeInputStream.URLOpener This class wraps a URL and provides method to open connection.

字段概要

字段

限定符和类型	字段和说明
protected long	currentPos
protected Long	fileLength
protected InputStream	in
protected ByteRangeInputStream.URLOpener	originalURL
protected ByteRangeInputStream.URLOpener	resolvedURL
protected long	startPos

构造器概要

构造器

构造器和说明
ByteRangeInputStream(ByteRangeInputStream.URLOpener o, ByteRangeInputStream.URLOpener r) Create with the specified URLOpeners.

方法概要

方法

限定符和类型	方法和说明
void	close()
protected InputStream	getInputStream()
long	getPos() Return the current offset from the start of the file
protected abstract URL	getResolvedUrl(HttpURLConnection connection)
protected InputStream	openInputStream()
int	read()
int	read(byte[] b, int off, int len)
void	seek(long pos) Seek to the given offset from the start of the file.
boolean	seekToNewSource(long targetPos) Seeks a different copy of the data.

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

read, readFully, readFully

从类继承的方法 java.io.InputStream

available, mark, markSupported, read, reset, skip

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

in

protected InputStream in

originalURL

protected ByteRangeInputStream.URLOpener originalURL

resolvedURL

protected ByteRangeInputStream.URLOpener resolvedURL

startPos

protected long startPos

currentPos

protected long currentPos

fileLength

protected Long fileLength

构造器详细资料

ByteRangeInputStream

public ByteRangeInputStream(ByteRangeInputStream.URLOpener o,
                    ByteRangeInputStream.URLOpener r)

Create with the specified URLOpeners. Original url is used to open the stream for the first time. Resolved url is used in subsequent requests.

参数:

o - Original url

r - Resolved url

方法详细资料

getResolvedUrl

protected abstract URL getResolvedUrl(HttpURLConnection connection)
                               throws IOException

抛出:

IOException

getInputStream

protected InputStream getInputStream()
                              throws IOException

抛出:

IOException

openInputStream

protected InputStream openInputStream()
                               throws IOException

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[] b,
       int off,
       int len)
         throws IOException

覆盖:

read 在类中 InputStream

抛出:

IOException

seek

public void seek(long pos)
          throws IOException

Seek to the given offset from the start of the file. The next read() will be from that location. Can't seek past the end of the file.

指定者:

seek 在接口中 Seekable

指定者:

seek 在类中 FSInputStream

抛出:

IOException

getPos

public long getPos()
            throws IOException

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

seekToNewSource

public boolean seekToNewSource(long targetPos)
                        throws IOException

Seeks a different copy of the data. Returns true if found a new source, false otherwise.

指定者:

seekToNewSource 在接口中 Seekable

指定者:

seekToNewSource 在类中 FSInputStream

抛出:

IOException

close

public void close()
           throws IOException

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