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

Class CpioArchiveOutputStream

  • All Implemented Interfaces:
    Closeable, Flushable, AutoCloseable, CpioConstants
    public class CpioArchiveOutputStream
extends ArchiveOutputStream
implements CpioConstants
    CpioArchiveOutputStream is a stream for writing CPIO streams. All formats of CPIO are supported (old ASCII, old binary, new portable format and the new portable format with CRC).

    An entry can be written by creating an instance of CpioArchiveEntry and fill it with the necessary values and put it into the CPIO stream. Afterwards write the contents of the file into the CPIO stream. Either close the stream by calling finish() or put a next entry into the cpio stream.

     CpioArchiveOutputStream out = new CpioArchiveOutputStream(
         new FileOutputStream(new File("test.cpio")));
 CpioArchiveEntry entry = new CpioArchiveEntry();
 entry.setName("testfile");
 String contents = "12345";
 entry.setFileSize(contents.length());
 entry.setMode(CpioConstants.C_ISREG); // regular file
 ... set other attributes, e.g. time, number of links
 out.putArchiveEntry(entry);
 out.write(testContents.getBytes());
 out.close();

    Note: This implementation should be compatible to cpio 2.5

    This class uses mutable fields and is not considered threadsafe.

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

    • Constructor Detail

      • CpioArchiveOutputStream

        public CpioArchiveOutputStream​(OutputStream out,
                               short format)
        Construct the cpio output stream with a specified format, a blocksize of BLOCK_SIZE and using ASCII as the file name encoding.
        Parameters:
        out - The cpio stream
        format - The format of the stream

      • CpioArchiveOutputStream

        public CpioArchiveOutputStream​(OutputStream out,
                               short format,
                               int blockSize)
        Construct the cpio output stream with a specified format using ASCII as the file name encoding.
        Parameters:
        out - The cpio stream
        format - The format of the stream
        blockSize - The block size of the archive.
        Since:
        1.1

      • CpioArchiveOutputStream

        public CpioArchiveOutputStream​(OutputStream out,
                               short format,
                               int blockSize,
                               String encoding)
        Construct the cpio output stream with a specified format using ASCII as the file name encoding.
        Parameters:
        out - The cpio stream
        format - The format of the stream
        blockSize - The block size of the archive.
        encoding - The encoding of file names to write - use null for the platform's default.
        Since:
        1.6

      • CpioArchiveOutputStream

        public CpioArchiveOutputStream​(OutputStream out)
        Construct the cpio output stream. The format for this CPIO stream is the "new" format using ASCII encoding for file names
        Parameters:
        out - The cpio stream

      • CpioArchiveOutputStream

        public CpioArchiveOutputStream​(OutputStream out,
                               String encoding)
        Construct the cpio output stream. The format for this CPIO stream is the "new" format.
        Parameters:
        out - The cpio stream
        encoding - The encoding of file names to write - use null for the platform's default.
        Since:
        1.6

    • Method Detail

      • putArchiveEntry

        public void putArchiveEntry​(ArchiveEntry entry)
                     throws IOException
        Begins writing a new CPIO file entry and positions the stream to the start of the entry data. Closes the current entry if still active. The current time will be used if the entry has no set modification time and the default header format will be used if no other format is specified in the entry.
        Specified by:
        putArchiveEntry in class ArchiveOutputStream
        Parameters:
        entry - the CPIO cpioEntry to be written
        Throws:
        IOException - if an I/O error has occurred or if a CPIO file error has occurred
        ClassCastException - if entry is not an instance of CpioArchiveEntry

      • write

        public void write​(byte[] b,
                  int off,
                  int len)
           throws IOException
        Writes an array of bytes to the current CPIO entry data. This method will block until all the bytes are written.
        Overrides:
        write in class OutputStream
        Parameters:
        b - the data to be written
        off - the start offset in the data
        len - the number of bytes that are written
        Throws:
        IOException - if an I/O error has occurred or if a CPIO file error has occurred

      • finish

        public void finish()
            throws IOException
        Finishes writing the contents of the CPIO output stream without closing the underlying stream. Use this method when applying multiple filters in succession to the same output stream.
        Specified by:
        finish in class ArchiveOutputStream
        Throws:
        IOException - if an I/O exception has occurred or if a CPIO file error has occurred