Package org.apache.commons.compress.archivers.cpio

Class CpioArchiveInputStream

java.lang.Object

java.io.InputStream

org.apache.commons.compress.archivers.ArchiveInputStream

org.apache.commons.compress.archivers.cpio.CpioArchiveInputStream

All Implemented Interfaces:

java.io.Closeable, java.lang.AutoCloseable, CpioConstants

public class CpioArchiveInputStream
extends ArchiveInputStream
implements CpioConstants

CpioArchiveInputStream is a stream for reading cpio streams. All formats of cpio are supported (old ascii, old binary, new portable format and the new portable format with crc).

The stream can be read by extracting a cpio entry (containing all informations about a entry) and afterwards reading from the stream the file specified by the entry.

 CpioArchiveInputStream cpioIn = new CpioArchiveInputStream(
         Files.newInputStream(Paths.get("test.cpio")));
 CpioArchiveEntry cpioEntry;

 while ((cpioEntry = cpioIn.getNextEntry()) != null) {
     System.out.println(cpioEntry.getName());
     int tmp;
     StringBuilder buf = new StringBuilder();
     while ((tmp = cpIn.read()) != -1) {
         buf.append((char) tmp);
     }
     System.out.println(buf.toString());
 }
 cpioIn.close();
 

Note: This implementation should be compatible to cpio 2.5

This class uses mutable fields and is not considered to be threadsafe.

Based on code from the jRPM project (jrpm.sourceforge.net)

Field Summary

Fields

Modifier and Type	Field	Description
private int	blockSize
private boolean	closed
private long	crc
(package private) java.lang.String	encoding
private CpioArchiveEntry	entry
private long	entryBytesRead
private boolean	entryEOF
private byte[]	fourBytesBuf
private java.io.InputStream	in
private byte[]	sixBytesBuf
private byte[]	tmpbuf
private byte[]	twoBytesBuf
private ZipEncoding	zipEncoding	The encoding to use for file names and labels.

Fields inherited from interface org.apache.commons.compress.archivers.cpio.CpioConstants

BLOCK_SIZE, C_IRGRP, C_IROTH, C_IRUSR, C_ISBLK, C_ISCHR, C_ISDIR, C_ISFIFO, C_ISGID, C_ISLNK, C_ISNWK, C_ISREG, C_ISSOCK, C_ISUID, C_ISVTX, C_IWGRP, C_IWOTH, C_IWUSR, C_IXGRP, C_IXOTH, C_IXUSR, CPIO_TRAILER, FORMAT_NEW, FORMAT_NEW_CRC, FORMAT_NEW_MASK, FORMAT_OLD_ASCII, FORMAT_OLD_BINARY, FORMAT_OLD_MASK, MAGIC_NEW, MAGIC_NEW_CRC, MAGIC_OLD_ASCII, MAGIC_OLD_BINARY, S_IFMT

Constructor Summary

Constructors

Constructor	Description
CpioArchiveInputStream(java.io.InputStream in)	Construct the cpio input stream with a blocksize of BLOCK_SIZE and expecting ASCII file names.
CpioArchiveInputStream(java.io.InputStream in, int blockSize)	Construct the cpio input stream with a blocksize of BLOCK_SIZE expecting ASCII file names.
CpioArchiveInputStream(java.io.InputStream in, int blockSize, java.lang.String encoding)	Construct the cpio input stream with a blocksize of BLOCK_SIZE.
CpioArchiveInputStream(java.io.InputStream in, java.lang.String encoding)	Construct the cpio input stream with a blocksize of BLOCK_SIZE.

Method Summary

Modifier and Type	Method	Description
int	available()	Returns 0 after EOF has reached for the current entry data, otherwise always return 1.
void	close()	Closes the CPIO input stream.
private void	closeEntry()	Closes the current CPIO entry and positions the stream for reading the next entry.
private void	ensureOpen()	Check to make sure that this stream has not been closed
CpioArchiveEntry	getNextCPIOEntry()	Reads the next CPIO file entry and positions stream at the beginning of the entry data.
ArchiveEntry	getNextEntry()	Returns the next Archive Entry in this Stream.
static boolean	matches(byte[] signature, int length)	Checks if the signature matches one of the following magic values: Strings: "070701" - MAGIC_NEW "070702" - MAGIC_NEW_CRC "070707" - MAGIC_OLD_ASCII Octal Binary value: 070707 - MAGIC_OLD_BINARY (held as a short) = 0x71C7 or 0xC771
int	read(byte[] b, int off, int len)	Reads from the current CPIO entry into an array of bytes.
private long	readAsciiLong(int length, int radix)
private long	readBinaryLong(int length, boolean swapHalfWord)
private java.lang.String	readCString(int length)
private int	readFully(byte[] b, int off, int len)
private CpioArchiveEntry	readNewEntry(boolean hasCrc)
private CpioArchiveEntry	readOldAsciiEntry()
private CpioArchiveEntry	readOldBinaryEntry(boolean swapHalfWord)
private byte[]	readRange(int len)
private void	skip(int bytes)
long	skip(long n)	Skips specified number of bytes in the current CPIO entry.
private void	skipRemainderOfLastBlock()	Skips the padding zeros written after the TRAILER!!! entry.

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

canReadEntryData, count, count, getBytesRead, getCount, pushedBackBytes, read

Methods inherited from class java.io.InputStream

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

Methods inherited from class java.lang.Object

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

Field Detail

closed

private boolean closed

entry

private CpioArchiveEntry entry

entryBytesRead

private long entryBytesRead

entryEOF

private boolean entryEOF

tmpbuf

private final byte[] tmpbuf

crc

private long crc

in

private final java.io.InputStream in

twoBytesBuf

private final byte[] twoBytesBuf

fourBytesBuf

private final byte[] fourBytesBuf

sixBytesBuf

private final byte[] sixBytesBuf

blockSize

private final int blockSize

zipEncoding

private final ZipEncoding zipEncoding

The encoding to use for file names and labels.

encoding

final java.lang.String encoding

Constructor Detail

CpioArchiveInputStream

public CpioArchiveInputStream(java.io.InputStream in)

Construct the cpio input stream with a blocksize of BLOCK_SIZE and expecting ASCII file names.

Parameters:

in - The cpio stream

CpioArchiveInputStream

public CpioArchiveInputStream(java.io.InputStream in,
                              java.lang.String encoding)

Construct the cpio input stream with a blocksize of BLOCK_SIZE.

Parameters:

in - The cpio stream

encoding - The encoding of file names to expect - use null for the platform's default.

Since:

1.6

CpioArchiveInputStream

public CpioArchiveInputStream(java.io.InputStream in,
                              int blockSize)

Construct the cpio input stream with a blocksize of BLOCK_SIZE expecting ASCII file names.

Parameters:

in - The cpio stream

blockSize - The block size of the archive.

Since:

1.5

CpioArchiveInputStream

public CpioArchiveInputStream(java.io.InputStream in,
                              int blockSize,
                              java.lang.String encoding)

Construct the cpio input stream with a blocksize of BLOCK_SIZE.

Parameters:

in - The cpio stream

blockSize - The block size of the archive.

encoding - The encoding of file names to expect - use null for the platform's default.

Throws:

java.lang.IllegalArgumentException - if blockSize is not bigger than 0

Since:

1.6

Method Detail

available

public int available()
              throws java.io.IOException

Returns 0 after EOF has reached for the current entry data, otherwise always return 1.

Programs should not count on this method to return the actual number of bytes that could be read without blocking.

Overrides:

available in class java.io.InputStream

Returns:

1 before EOF and 0 after EOF has reached for current entry.

Throws:

java.io.IOException - if an I/O error has occurred or if a CPIO file error has occurred

close

public void close()
           throws java.io.IOException

Closes the CPIO input stream.

Specified by:

close in interface java.lang.AutoCloseable

Specified by:

close in interface java.io.Closeable

Overrides:

close in class java.io.InputStream

Throws:

java.io.IOException - if an I/O error has occurred

closeEntry

private void closeEntry()
                 throws java.io.IOException

Closes the current CPIO entry and positions the stream for reading the next entry.

Throws:

java.io.IOException - if an I/O error has occurred or if a CPIO file error has occurred

ensureOpen

private void ensureOpen()
                 throws java.io.IOException

Check to make sure that this stream has not been closed

Throws:

java.io.IOException - if the stream is already closed

getNextCPIOEntry

public CpioArchiveEntry getNextCPIOEntry()
                                  throws java.io.IOException

Reads the next CPIO file entry and positions stream at the beginning of the entry data.

Returns:

the CpioArchiveEntry just read

Throws:

java.io.IOException - if an I/O error has occurred or if a CPIO file error has occurred

skip

private void skip(int bytes)
           throws java.io.IOException

Throws:

java.io.IOException

read

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

Reads from the current CPIO entry into an array of bytes. Blocks until some input is available.

Overrides:

read in class java.io.InputStream

Parameters:

b - the buffer into which the data is read

off - the start offset of the data

len - the maximum number of bytes read

Returns:

the actual number of bytes read, or -1 if the end of the entry is reached

Throws:

java.io.IOException - if an I/O error has occurred or if a CPIO file error has occurred

readFully

private final int readFully(byte[] b,
                            int off,
                            int len)
                     throws java.io.IOException

Throws:

java.io.IOException

readRange

private final byte[] readRange(int len)
                        throws java.io.IOException

Throws:

java.io.IOException

readBinaryLong

private long readBinaryLong(int length,
                            boolean swapHalfWord)
                     throws java.io.IOException

Throws:

java.io.IOException

readAsciiLong

private long readAsciiLong(int length,
                           int radix)
                    throws java.io.IOException

Throws:

java.io.IOException

readNewEntry

private CpioArchiveEntry readNewEntry(boolean hasCrc)
                               throws java.io.IOException

Throws:

java.io.IOException

readOldAsciiEntry

private CpioArchiveEntry readOldAsciiEntry()
                                    throws java.io.IOException

Throws:

java.io.IOException

readOldBinaryEntry

private CpioArchiveEntry readOldBinaryEntry(boolean swapHalfWord)
                                     throws java.io.IOException

Throws:

java.io.IOException

readCString

private java.lang.String readCString(int length)
                              throws java.io.IOException

Throws:

java.io.IOException

skip

public long skip(long n)
          throws java.io.IOException

Skips specified number of bytes in the current CPIO entry.

Overrides:

skip in class java.io.InputStream

Parameters:

n - the number of bytes to skip

Returns:

the actual number of bytes skipped

Throws:

java.io.IOException - if an I/O error has occurred

java.lang.IllegalArgumentException - if n < 0

getNextEntry

public ArchiveEntry getNextEntry()
                          throws java.io.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:

java.io.IOException - if the next entry could not be read

skipRemainderOfLastBlock

private void skipRemainderOfLastBlock()
                               throws java.io.IOException

Skips the padding zeros written after the TRAILER!!! entry.

Throws:

java.io.IOException

matches

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

Checks if the signature matches one of the following magic values: Strings: "070701" - MAGIC_NEW "070702" - MAGIC_NEW_CRC "070707" - MAGIC_OLD_ASCII Octal Binary value: 070707 - MAGIC_OLD_BINARY (held as a short) = 0x71C7 or 0xC771

Parameters:

signature - data to match

length - length of data

Returns:

whether the buffer seems to contain CPIO data