uk.ac.starlink.util.bzip2

Class CBZip2InputStream

java.lang.Object

java.io.InputStream

uk.ac.starlink.util.bzip2.CBZip2InputStream

All Implemented Interfaces:

Closeable, AutoCloseable, BZip2Constants

public class CBZip2InputStream
extends InputStream
implements BZip2Constants

An input stream that decompresses from the BZip2 format (without the file header chars) to be read as any other stream.

The decompression requires large amounts of memory. Thus you should call the close() method as soon as possible, to force CBZip2InputStream to release the allocated memory. See CBZip2OutputStream for information about memory usage.

CBZip2InputStream reads bytes from the compressed source stream via the single byte read() method exclusively. Thus you should consider to use a buffered source stream.

Instances of this class are not threadsafe.

Field Summary

Fields inherited from interface uk.ac.starlink.util.bzip2.BZip2Constants

baseBlockSize, G_SIZE, MAX_ALPHA_SIZE, MAX_CODE_LEN, MAX_SELECTORS, N_GROUPS, N_ITERS, NUM_OVERSHOOT_BYTES, rNums, RUNA, RUNB

Constructor Summary

Constructors

Constructor and Description
CBZip2InputStream(InputStream in) Constructs a new CBZip2InputStream which decompresses bytes read from the specified stream.
CBZip2InputStream(InputStream in, boolean decompressConcatenated) Constructs a new CBZip2InputStream which decompresses bytes read from the specified stream.

Method Summary

Modifier and Type	Method and Description
void	close()
int	read()
int	read(byte[] dest, int offs, int len)

Methods inherited from class java.io.InputStream

available, mark, markSupported, read, reset, skip

Methods inherited from class java.lang.Object

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

Constructor Detail

CBZip2InputStream

public CBZip2InputStream(InputStream in)
                  throws IOException

Constructs a new CBZip2InputStream which decompresses bytes read from the specified stream. This doesn't support decompressing concatenated .bz2 files.

Although BZip2 headers are marked with the magic "Bz" this constructor expects the next byte in the stream to be the first one after the magic. Thus callers have to skip the first two bytes. Otherwise this constructor will throw an exception.

Parameters:

in - InputStream

Throws:

IOException - if the stream content is malformed or an I/O error occurs.

NullPointerException - if in == null

CBZip2InputStream

public CBZip2InputStream(InputStream in,
                         boolean decompressConcatenated)
                  throws IOException

Constructs a new CBZip2InputStream which decompresses bytes read from the specified stream.

Although BZip2 headers are marked with the magic "Bz" this constructor expects the next byte in the stream to be the first one after the magic. Thus callers have to skip the first two bytes. Otherwise this constructor will throw an exception.

Parameters:

in - the InputStream from which this object should be created

decompressConcatenated - if true, decompress until the end of the input; if false, stop after the first .bz2 stream and leave the input position to point to the next byte after the .bz2 stream

Throws:

IOException - if the stream content is malformed or an I/O error occurs.

NullPointerException - if in == null

Method Detail

read

public int read()
         throws IOException

Specified by:

read in class InputStream

Throws:

IOException

read

public int read(byte[] dest,
                int offs,
                int len)
         throws IOException

Overrides:

read in class InputStream

Throws:

IOException

close

public void close()
           throws IOException

Specified by:

close in interface Closeable

Specified by:

close in interface AutoCloseable

Overrides:

close in class InputStream

Throws:

IOException