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

Class CpioArchiveInputStream

  • All Implemented Interfaces:
    java.io.Closeable, java.lang.AutoCloseable, CpioConstants
    public class CpioArchiveInputStream
extends ArchiveInputStream<CpioArchiveEntry>
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 information about an 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 Detail

      • closed

        private boolean closed

      • entryBytesRead

        private long entryBytesRead

      • entryEOF

        private boolean entryEOF

      • tmpbuf

        private final byte[] tmpbuf

      • crc

        private long crc

      • twoBytesBuf

        private final byte[] twoBytesBuf
        Cached buffer - must only be used locally in the class (COMPRESS-172 - reduce garbage collection).

      • fourBytesBuf

        private final byte[] fourBytesBuf
        Cached buffer - must only be used locally in the class (COMPRESS-172 - reduce garbage collection).

      • sixBytesBuf

        private final byte[] sixBytesBuf

      • blockSize

        private final int blockSize

      • zipEncoding

        private final ZipEncoding zipEncoding
        The encoding to use for file names and labels.

    • Constructor Detail

      • CpioArchiveInputStream

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

      • CpioArchiveInputStream

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

    • Method Detail

      • 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

      • 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.FilterInputStream
        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.FilterInputStream
        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

        @Deprecated
public CpioArchiveEntry getNextCPIOEntry()
                                  throws java.io.IOException
        Deprecated.
        Use getNextEntry().
        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

      • 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.FilterInputStream
        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

      • readAsciiLong

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

      • readBinaryLong

        private long readBinaryLong​(int length,
                            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

      • readFully

        private int readFully​(byte[] b,
                      int off,
                      int len)
               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

      • readRange

        private byte[] readRange​(int len)
                  throws java.io.IOException
        Throws:
        java.io.IOException

      • skip

        private void skip​(int bytes)
           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.FilterInputStream
        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

      • skipRemainderOfLastBlock

        private void skipRemainderOfLastBlock()
                               throws java.io.IOException
        Skips the padding zeros written after the TRAILER!!! entry.
        Throws:
        java.io.IOException