Package org.apache.commons.compress.utils

Class FixedLengthBlockOutputStream

java.lang.Object

java.io.OutputStream

org.apache.commons.compress.utils.FixedLengthBlockOutputStream

All Implemented Interfaces:

Closeable, Flushable, AutoCloseable, Channel, WritableByteChannel

public class FixedLengthBlockOutputStream
extends OutputStream
implements WritableByteChannel

This class supports writing to an OutputStream or WritableByteChannel in fixed length blocks.

It can be be used to support output to devices such as tape drives that require output in this format. If the final block does not have enough content to fill an entire block, the output will be padded to a full block size.

This class can be used to support TAR,PAX, and CPIO blocked output to character special devices. It is not recommended that this class be used unless writing to such devices, as the padding serves no useful purpose in such cases.

This class should normally wrap a FileOutputStream or associated WritableByteChannel directly. If there is an intervening filter that modified the output, such as a CompressorOutputStream, or performs its own buffering, such as BufferedOutputStream, output to the device may no longer be of the specified size.

Any content written to this stream should be self-delimiting and should tolerate any padding added to fill the last block.

Since:

1.15

Constructor Summary

Constructors

Constructor	Description
FixedLengthBlockOutputStream(OutputStream os, int blockSize)	Create a fixed length block output stream with given destination stream and block size
FixedLengthBlockOutputStream(WritableByteChannel out, int blockSize)	Create a fixed length block output stream with given destination writable byte channel and block size

Method Summary

Modifier and Type	Method	Description
void	close()
void	flushBlock()	Potentially pads and then writes the current block to the underlying stream.
boolean	isOpen()
void	write(byte[] b, int offset, int length)
void	write(int b)
int	write(ByteBuffer src)

Methods inherited from class java.io.OutputStream

flush, nullOutputStream, write

Methods inherited from class java.lang.Object

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

Constructor Detail

FixedLengthBlockOutputStream

public FixedLengthBlockOutputStream(OutputStream os,
                                    int blockSize)

Create a fixed length block output stream with given destination stream and block size

Parameters:

os - The stream to wrap.

blockSize - The block size to use.

FixedLengthBlockOutputStream

public FixedLengthBlockOutputStream(WritableByteChannel out,
                                    int blockSize)

Create a fixed length block output stream with given destination writable byte channel and block size

Parameters:

out - The writable byte channel to wrap.

blockSize - The block size to use.

Method Detail

write

public void write(int b)
           throws IOException

Specified by:

write in class OutputStream

Throws:

IOException

write

public void write(byte[] b,
                  int offset,
                  int length)
           throws IOException

Overrides:

write in class OutputStream

Throws:

IOException

write

public int write(ByteBuffer src)
          throws IOException

Specified by:

write in interface WritableByteChannel

Throws:

IOException

isOpen

public boolean isOpen()

Specified by:

isOpen in interface Channel

flushBlock

public void flushBlock()
                throws IOException

Potentially pads and then writes the current block to the underlying stream.

Throws:

IOException - if writing fails

close

public void close()
           throws IOException

Specified by:

close in interface AutoCloseable

Specified by:

close in interface Channel

Specified by:

close in interface Closeable

Overrides:

close in class OutputStream

Throws:

IOException