Class ImportFileInputStream

java.lang.Object

java.io.InputStream

org.apache.derby.impl.load.ImportFileInputStream

All Implemented Interfaces:

Closeable, AutoCloseable

class ImportFileInputStream
extends InputStream

An InputStream, which can stream data from a file, starting from any offset in the file. This stream operates on top of a RandomAccessFile object. This class overrides InputStream methods to read from the given RandomAccessFile and provides an addtional method seek(..) to position the stream at offset in the file.

Field Summary

Fields

Modifier and Type	Field	Description
private long	currentPosition
private long	fileLength
private RandomAccessFile	raf

Constructor Summary

Constructors

Constructor	Description
ImportFileInputStream(RandomAccessFile raf)	Create a ImportFileInputStream object for the given file.

Method Summary

Modifier and Type	Method	Description
int	available()	Returns the number of bytes that can be read from this stream.
void	close()	Closes this input stream and releases any associated resources
int	read()	Reads a byte of data from this input stream.
int	read(byte[] buf, int offset, int length)	Reads up to length bytes of data from this input stream into given array.
(package private) void	seek(long offset)	Sets the file offset at which the next read will occur.

Methods inherited from class InputStream

mark, markSupported, nullInputStream, read, readAllBytes, readNBytes, readNBytes, reset, skip, skipNBytes, transferTo

Methods inherited from class Object

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

Field Details

raf

private RandomAccessFile raf

currentPosition

private long currentPosition

fileLength

private long fileLength

Constructor Details

ImportFileInputStream

ImportFileInputStream(RandomAccessFile raf)
               throws IOException

Create a ImportFileInputStream object for the given file.

Parameters:

raf - file the stream reads from.

Throws:

IOException - if any I/O error occurs.

Method Details

seek

void seek(long offset)
   throws IOException

Sets the file offset at which the next read will occur.

Parameters:

offset - byte offset in the file.

Throws:

IOException - if an I/O error occurs.

read

public int read()
         throws IOException

Reads a byte of data from this input stream.

Specified by:

read in class InputStream

Throws:

IOException - if an I/O error occurs.

read

public int read(byte[] buf,
 int offset,
 int length)
         throws IOException

Reads up to length bytes of data from this input stream into given array. This method blocks until some input is available.

Overrides:

read in class InputStream

Parameters:

buf - the buffer into which the data is read.

offset - the start offset of the data.

length - the maximum number of bytes read.

Returns:

the total number of bytes read into the buffer, or -1 if there is no more data because the end of the file has been reached.

Throws:

IOException - if an I/O error occurs.

available

public int available()
              throws IOException

Returns the number of bytes that can be read from this stream.

Overrides:

available in class InputStream

Returns:

the number of bytes that can be read from this stream.

Throws:

IOException - if an I/O error occurs.

close

public void close()
           throws IOException

Closes this input stream and releases any associated resources

Specified by:

close in interface AutoCloseable

Specified by:

close in interface Closeable

Overrides:

close in class InputStream

Throws:

IOException - if an I/O error occurs.