org.apache.hadoop.fs

クラス FSInputStream

java.lang.Object

java.io.InputStream

org.apache.hadoop.fs.FSInputStream

すべての実装されたインタフェース:

Closeable, AutoCloseable, PositionedReadable, Seekable

@InterfaceAudience.Public
 @InterfaceStability.Evolving
public abstract class FSInputStream
extends InputStream
implements Seekable, PositionedReadable

FSInputStream is a generic old InputStream with a little bit of RAF-style seek ability.

コンストラクタのサマリー

コンストラクタ

コンストラクタと説明
FSInputStream()

メソッドのサマリー

修飾子とタイプ	メソッドと説明
abstract long	getPos() Return the current offset from the start of the file
int	read(long position, byte[] buffer, int offset, int length) Read up to the specified number of bytes, from a given position within a file, and return the number of bytes read.
void	readFully(long position, byte[] buffer) Read number of bytes equal to the length of the buffer, from a given position within a file.
void	readFully(long position, byte[] buffer, int offset, int length) Read the specified number of bytes, from a given position within a file.
abstract void	seek(long pos) Seek to the given offset from the start of the file.
abstract boolean	seekToNewSource(long targetPos) Seeks a different copy of the data.
protected void	validatePositionedReadArgs(long position, byte[] buffer, int offset, int length) Validation code, available for use in subclasses.

クラスから継承されたメソッド java.io.InputStream

available, close, mark, markSupported, read, read, read, reset, skip

クラスから継承されたメソッド java.lang.Object

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

コンストラクタの詳細

FSInputStream

public FSInputStream()

メソッドの詳細

seek

public abstract 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.

定義:

seek インタフェース内 Seekable

例外:

IOException

getPos

public abstract long getPos()
                     throws IOException

Return the current offset from the start of the file

定義:

getPos インタフェース内 Seekable

例外:

IOException

seekToNewSource

public abstract boolean seekToNewSource(long targetPos)
                                 throws IOException

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

例外:

IOException

read

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

インタフェースからコピーされた説明: PositionedReadable

Read up to the specified number of bytes, from a given position within a file, and return the number of bytes read. This does not change the current offset of a file, and is thread-safe. Warning: Not all filesystems satisfy the thread-safety requirement.

定義:

read インタフェース内 PositionedReadable

パラメータ:

position - position within file

buffer - destination buffer

offset - offset in the buffer

length - number of bytes to read

戻り値:

actual number of bytes read; -1 means "none"

例外:

IOException - IO problems.

validatePositionedReadArgs

protected void validatePositionedReadArgs(long position,
                                          byte[] buffer,
                                          int offset,
                                          int length)
                                   throws EOFException

Validation code, available for use in subclasses.

パラメータ:

position - position: if negative an EOF exception is raised

buffer - destination buffer

offset - offset within the buffer

length - length of bytes to read

例外:

EOFException - if the position is negative

IndexOutOfBoundsException - if there isn't space for the amount of data requested.

IllegalArgumentException - other arguments are invalid.

readFully

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

インタフェースからコピーされた説明: PositionedReadable

Read the specified number of bytes, from a given position within a file. This does not change the current offset of a file, and is thread-safe. Warning: Not all filesystems satisfy the thread-safety requirement.

定義:

readFully インタフェース内 PositionedReadable

パラメータ:

position - position within file

buffer - destination buffer

offset - offset in the buffer

length - number of bytes to read

例外:

IOException - IO problems.

EOFException - the end of the data was reached before the read operation completed

readFully

public void readFully(long position,
                      byte[] buffer)
               throws IOException

インタフェースからコピーされた説明: PositionedReadable

Read number of bytes equal to the length of the buffer, from a given position within a file. This does not change the current offset of a file, and is thread-safe. Warning: Not all filesystems satisfy the thread-safety requirement.

定義:

readFully インタフェース内 PositionedReadable

パラメータ:

position - position within file

buffer - destination buffer

例外:

IOException - IO problems.

EOFException - the end of the data was reached before the read operation completed