Module de.bernd_michaely.common.io.random

Package de.bernd_michaely.common.io.random

Class RadInputStream

java.lang.Object

java.io.InputStream

de.bernd_michaely.common.io.random.RadInputStream

All Implemented Interfaces:

Closeable, AutoCloseable

public class RadInputStream
extends InputStream

InputStream based on a RandomAccessData data source. It provides a view to a subregion of the underlying data source through an InputStream. The usage would happen typically in two stages:

1. Use a RandomAccessData instance directly to efficiently locate offset and length of the embedded data.
2. Create a RadInputStream object on the RandomAccessData instance to access the embedded data through an InputStream.

Example:

 RandomAccessData randomAccessData = RandomAccessDataFactory.createInstance(...);
 X3fImageData imageData = ...
 try (InputStream is = new RadInputStream(
        randomAccessData, imageData.getDataOffset(), imageData.getDataLength()))
 {
        ...
 }
 

Constructor Summary

Constructors

Constructor	Description
RadInputStream(RandomAccessData randomAccessData)	Provides a view to the underlying RandomAccessData data source in full length as an InputStream.
RadInputStream(RandomAccessData randomAccessData, long offset, long length)	Provides a view to a subregion of the underlying RandomAccessData data source as an InputStream.

Method Summary

Modifier and Type	Method	Description
int	available()
void	close()	Closes this stream and releases any system resources associated with it.
boolean	isClosed()	Returns true, if this stream has been closed.
void	mark(int readlimit)	Remembers the current position of this stream.
boolean	markSupported()	This input stream does not support marking with remembering of data.
int	read()
int	read(byte[] b, int off, int len)
void	reset()	Repositions this stream to the last marked position.
long	skip(long n)	Seeks efficiently relative to the current position to any offset within the data source.

Methods inherited from class java.io.InputStream

nullInputStream, read, readAllBytes, readNBytes, readNBytes, transferTo

Methods inherited from class java.lang.Object

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

Constructor Detail

RadInputStream

public RadInputStream(RandomAccessData randomAccessData)
               throws RandomAccessDataException

Provides a view to the underlying RandomAccessData data source in full length as an InputStream.

Parameters:

randomAccessData - the underlying data source

Throws:

RandomAccessDataException - if an error occurs during I/O operation

RadInputStream

public RadInputStream(RandomAccessData randomAccessData,
                      long offset,
                      long length)
               throws RandomAccessDataException

Provides a view to a subregion of the underlying RandomAccessData data source as an InputStream.

Parameters:

randomAccessData - the underlying data source

offset - start index within the underlying data source

length - the length in bytes of the view of the embedded data

Throws:

RandomAccessDataException - if an error occurs during I/O operation

Method Detail

available

public int available()
              throws IOException

Overrides:

available in class InputStream

Throws:

IOException

isClosed

public boolean isClosed()

Returns true, if this stream has been closed.

Returns:

true, if this stream has been closed

close

public void close()

Closes this stream and releases any system resources associated with it. If the stream is already closed then invoking this method has no effect. Note, that this method does not close the underlying RandomAccessData object.

Specified by:

close in interface AutoCloseable

Specified by:

close in interface Closeable

Overrides:

close in class InputStream

mark

public void mark(int readlimit)

Remembers the current position of this stream. No data will be remembered. That is, after a call to reset(), subsequent reads may or may not re-read the same data, if the underlying data source has been written to.

Overrides:

mark in class InputStream

Parameters:

readlimit - has no effect for this stream type

markSupported

public boolean markSupported()

This input stream does not support marking with remembering of data. It does however support efficient repositioning and skipping within the data source.

Overrides:

markSupported in class InputStream

Returns:

false

read

public int read()
         throws IOException

Specified by:

read in class InputStream

Throws:

IOException

read

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

Overrides:

read in class InputStream

Throws:

IOException

reset

public void reset()
           throws IOException

Repositions this stream to the last marked position. It does not remember any data, that is, subsequent reads may or may not re-read the same data, if the underlying data source has been written to.

Overrides:

reset in class InputStream

Throws:

IOException - if an error occurs during I/O operation

skip

public long skip(long n)
          throws IOException

Seeks efficiently relative to the current position to any offset within the data source. It is possible to jump backwards with negative values.

Overrides:

skip in class InputStream

Parameters:

n - the number of bytes to seek, negative value to jump backwards

Returns:

the number of bytes actually skipped

Throws:

IOException - if an error occurs during I/O operation