Package org.apache.commons.compress.archivers.dump

Class DumpArchiveInputStream

java.lang.Object

java.io.InputStream

org.apache.commons.compress.archivers.ArchiveInputStream

org.apache.commons.compress.archivers.dump.DumpArchiveInputStream

All Implemented Interfaces:

Closeable, AutoCloseable

public class DumpArchiveInputStream
extends ArchiveInputStream

The DumpArchiveInputStream reads a UNIX dump archive as an InputStream. Methods are provided to position at each successive entry in the archive, and the read each entry as a normal input stream using read(). There doesn't seem to exist a hint on the encoding of string values in any piece documentation. Given the main purpose of dump/restore is backing up a system it seems very likely the format uses the current default encoding of the system.

This class is not thread-safe

Field Summary

Fields

Modifier and Type	Field	Description
protected org.apache.commons.compress.archivers.dump.TapeInputStream	raw

Constructor Summary

Constructors

Constructor	Description
DumpArchiveInputStream(InputStream is)	Constructor using the platform's default encoding for file names.
DumpArchiveInputStream(InputStream is, String encoding)	Constructor.

Method Summary

Modifier and Type	Method	Description
void	close()	Closes the stream for this entry.
long	getBytesRead()	Returns the current number of bytes read from this stream.
int	getCount()	Deprecated.
DumpArchiveEntry	getNextDumpEntry()	Read the next entry.
DumpArchiveEntry	getNextEntry()	Returns the next Archive Entry in this Stream.
DumpArchiveSummary	getSummary()	Return the archive summary information.
static boolean	matches(byte[] buffer, int length)	Look at the first few bytes of the file to decide if it's a dump archive.
int	read(byte[] buf, int off, int len)	Reads bytes from the current dump archive entry.

Methods inherited from class org.apache.commons.compress.archivers.ArchiveInputStream

canReadEntryData, count, count, pushedBackBytes, read

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

Field Details

raw

protected org.apache.commons.compress.archivers.dump.TapeInputStream raw

Constructor Details

DumpArchiveInputStream

public DumpArchiveInputStream(InputStream is)
                       throws ArchiveException

Constructor using the platform's default encoding for file names.

Parameters:

is - stream to read from

Throws:

ArchiveException - on error

DumpArchiveInputStream

public DumpArchiveInputStream(InputStream is,
 String encoding)
                       throws ArchiveException

Constructor.

Parameters:

is - stream to read from

encoding - the encoding to use for file names, use null for the platform's default encoding

Throws:

ArchiveException - on error

Since:

1.6

Method Details

matches

public static boolean matches(byte[] buffer,
 int length)

Look at the first few bytes of the file to decide if it's a dump archive. With 32 bytes we can look at the magic value, with a full 1k we can verify the checksum.

Parameters:

buffer - data to match

length - length of data

Returns:

whether the buffer seems to contain dump data

close

public void close()
           throws IOException

Closes the stream for this entry.

Specified by:

close in interface AutoCloseable

Specified by:

close in interface Closeable

Overrides:

close in class InputStream

Throws:

IOException

getBytesRead

public long getBytesRead()

Description copied from class: ArchiveInputStream

Returns the current number of bytes read from this stream.

Overrides:

getBytesRead in class ArchiveInputStream

Returns:

the number of read bytes

getCount

@Deprecated
public int getCount()

Deprecated.

Description copied from class: ArchiveInputStream

Returns the current number of bytes read from this stream.

Overrides:

getCount in class ArchiveInputStream

Returns:

the number of read bytes

getNextDumpEntry

public DumpArchiveEntry getNextDumpEntry()
                                  throws IOException

Read the next entry.

Returns:

the next entry

Throws:

IOException - on error

getNextEntry

public DumpArchiveEntry getNextEntry()
                              throws IOException

Description copied from class: ArchiveInputStream

Returns the next Archive Entry in this Stream.

Specified by:

getNextEntry in class ArchiveInputStream

Returns:

the next entry, or null if there are no more entries

Throws:

IOException - if the next entry could not be read

getSummary

public DumpArchiveSummary getSummary()

Return the archive summary information.

Returns:

the summary

read

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

Reads bytes from the current dump archive entry. This method is aware of the boundaries of the current entry in the archive and will deal with them as if they were this stream's start and EOF.

Overrides:

read in class InputStream

Parameters:

buf - The buffer into which to place bytes read.

off - The offset at which to place bytes read.

len - The number of bytes to read.

Returns:

The number of bytes read, or -1 at EOF.

Throws:

IOException - on error