Package org.apache.commons.compress.utils

Class BitInputStream

  • All Implemented Interfaces:
    java.io.Closeable, java.lang.AutoCloseable
    public class BitInputStream
extends java.lang.Object
implements java.io.Closeable
    Reads bits from an InputStream.
    Since:
    1.10

    • Constructor Summary

      Constructors 
      Constructor Description
      BitInputStream​(java.io.InputStream in, java.nio.ByteOrder byteOrder)
      Constructor taking an InputStream and its bit arrangement.

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      void alignWithByteBoundary()
      Drops bits until the next bits will be read from a byte boundary.
      long bitsAvailable()
      Returns an estimate of the number of bits that can be read from this input stream without blocking by the next invocation of a method for this input stream.
      int bitsCached()
      Returns the number of bits that can be read from this input stream without reading from the underlying input stream at all.
      void clearBitCache()
      Clears the cache of bits that have been read from the underlying stream but not yet provided via readBits(int).
      void close()  
      long getBytesRead()
      Returns the number of bytes read from the underlying stream.
      long readBits​(int count)
      Returns at most 63 bits read from the underlying stream.

      • Methods inherited from class java.lang.Object

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

    • Constructor Detail

      • BitInputStream

        public BitInputStream​(java.io.InputStream in,
                      java.nio.ByteOrder byteOrder)
        Constructor taking an InputStream and its bit arrangement.
        Parameters:
        in - the InputStream
        byteOrder - the bit arrangement across byte boundaries, either BIG_ENDIAN (aaaaabbb bb000000) or LITTLE_ENDIAN (bbbaaaaa 000000bb)

    • Method Detail

      • close

        public void close()
           throws java.io.IOException
        Specified by:
        close in interface java.lang.AutoCloseable
        Specified by:
        close in interface java.io.Closeable
        Throws:
        java.io.IOException

      • clearBitCache

        public void clearBitCache()
        Clears the cache of bits that have been read from the underlying stream but not yet provided via readBits(int).

      • readBits

        public long readBits​(int count)
              throws java.io.IOException
        Returns at most 63 bits read from the underlying stream.
        Parameters:
        count - the number of bits to read, must be a positive number not bigger than 63.
        Returns:
        the bits concatenated as a long using the stream's byte order. -1 if the end of the underlying stream has been reached before reading the requested number of bits
        Throws:
        java.io.IOException - on error

      • bitsCached

        public int bitsCached()
        Returns the number of bits that can be read from this input stream without reading from the underlying input stream at all.
        Returns:
        estimate of the number of bits that can be read without reading from the underlying stream
        Since:
        1.16

      • bitsAvailable

        public long bitsAvailable()
                   throws java.io.IOException
        Returns an estimate of the number of bits that can be read from this input stream without blocking by the next invocation of a method for this input stream.
        Returns:
        estimate of the number of bits that can be read without blocking
        Throws:
        java.io.IOException - if the underlying stream throws one when calling available
        Since:
        1.16

      • alignWithByteBoundary

        public void alignWithByteBoundary()
        Drops bits until the next bits will be read from a byte boundary.
        Since:
        1.16

      • getBytesRead

        public long getBytesRead()
        Returns the number of bytes read from the underlying stream.

        This includes the bytes read to fill the current cache and not read as bits so far.

        Returns:
        the number of bytes read from the underlying stream
        Since:
        1.17