Package org.apache.commons.io.input

Class UnsynchronizedBufferedInputStream

  • All Implemented Interfaces:
    java.io.Closeable, java.lang.AutoCloseable
    public final class UnsynchronizedBufferedInputStream
extends UnsynchronizedFilterInputStream
    An unsynchronized version of BufferedInputStream, not thread-safe.

    Wraps an existing InputStream and buffers the input. Expensive interaction with the underlying input stream is minimized, since most (smaller) requests can be satisfied by accessing the buffer alone. The drawback is that some extra space is required to hold the buffer and that copying takes place when filling that buffer, but this is usually outweighed by the performance benefits.

    To build an instance, use UnsynchronizedBufferedInputStream.Builder.

    A typical application pattern for the class looks like this: 

     UnsynchronizedBufferedInputStream s = new UnsynchronizedBufferedInputStream.Builder().
   .setInputStream(new FileInputStream("file.java"))
   .setBufferSize(8192)
   .get();

    Provenance: Apache Harmony and modified.

    Since:
    2.12.0
    See Also:
    UnsynchronizedBufferedInputStream.Builder, BufferedInputStream

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      int available()
      Returns the number of bytes that are available before this stream will block.
      void close()
      Closes this stream.
      void mark​(int readLimit)
      Sets a mark position in this stream.
      boolean markSupported()
      Indicates whether BufferedInputStream supports the mark() and reset() methods.
      int read()
      Reads a single byte from this stream and returns it as an integer in the range from 0 to 255.
      int read​(byte[] dest, int offset, int length)
      Reads at most length bytes from this stream and stores them in byte array buffer starting at offset offset.
      void reset()
      Resets this stream to the last marked location.
      long skip​(long amount)
      Skips amount number of bytes in this stream.

      • Methods inherited from class java.io.InputStream

        nullInputStream, readAllBytes, readNBytes, readNBytes, transferTo

      • Methods inherited from class java.lang.Object

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

    • Method Detail

      • available

        public int available()
              throws java.io.IOException
        Returns the number of bytes that are available before this stream will block. This method returns the number of bytes available in the buffer plus those available in the source stream.
        Overrides:
        available in class UnsynchronizedFilterInputStream
        Returns:
        the number of bytes available before blocking.
        Throws:
        java.io.IOException - if this stream is closed.

      • close

        public void close()
           throws java.io.IOException
        Closes this stream. The source stream is closed and any resources associated with it are released.
        Specified by:
        close in interface java.lang.AutoCloseable
        Specified by:
        close in interface java.io.Closeable
        Overrides:
        close in class UnsynchronizedFilterInputStream
        Throws:
        java.io.IOException - if an error occurs while closing this stream.

      • mark

        public void mark​(int readLimit)
        Sets a mark position in this stream. The parameter readLimit indicates how many bytes can be read before a mark is invalidated. Calling reset() will reposition the stream back to the marked position if readLimit has not been surpassed. The underlying buffer may be increased in size to allow readLimit number of bytes to be supported.
        Overrides:
        mark in class UnsynchronizedFilterInputStream
        Parameters:
        readLimit - the number of bytes that can be read before the mark is invalidated.
        See Also:
        reset()

      • read

        public int read()
         throws java.io.IOException
        Reads a single byte from this stream and returns it as an integer in the range from 0 to 255. Returns -1 if the end of the source string has been reached. If the internal buffer does not contain any available bytes then it is filled from the source stream and the first byte is returned.
        Overrides:
        read in class UnsynchronizedFilterInputStream
        Returns:
        the byte read or -1 if the end of the source stream has been reached.
        Throws:
        java.io.IOException - if this stream is closed or another IOException occurs.

      • read

        public int read​(byte[] dest,
                int offset,
                int length)
         throws java.io.IOException
        Reads at most length bytes from this stream and stores them in byte array buffer starting at offset offset. Returns the number of bytes actually read or -1 if no bytes were read and the end of the stream was encountered. If all the buffered bytes have been used, a mark has not been set and the requested number of bytes is larger than the receiver's buffer size, this implementation bypasses the buffer and simply places the results directly into buffer.
        Overrides:
        read in class UnsynchronizedFilterInputStream
        Parameters:
        dest - the byte array in which to store the bytes read.
        offset - the initial position in buffer to store the bytes read from this stream.
        length - the maximum number of bytes to store in buffer.
        Returns:
        the number of bytes actually read or -1 if end of stream.
        Throws:
        java.lang.IndexOutOfBoundsException - if offset < 0 or length < 0, or if offset + length is greater than the size of buffer.
        java.io.IOException - if the stream is already closed or another IOException occurs.

      • reset

        public void reset()
           throws java.io.IOException
        Resets this stream to the last marked location.
        Overrides:
        reset in class UnsynchronizedFilterInputStream
        Throws:
        java.io.IOException - if this stream is closed, no mark has been set or the mark is no longer valid because more than readLimit bytes have been read since setting the mark.
        See Also:
        mark(int)

      • skip

        public long skip​(long amount)
          throws java.io.IOException
        Skips amount number of bytes in this stream. Subsequent read()'s will not return these bytes unless reset() is used.
        Overrides:
        skip in class UnsynchronizedFilterInputStream
        Parameters:
        amount - the number of bytes to skip. skip does nothing and returns 0 if amount is less than zero.
        Returns:
        the number of bytes actually skipped.
        Throws:
        java.io.IOException - if this stream is closed or another IOException occurs.
        See Also:
        UnsynchronizedFilterInputStream.mark(int), UnsynchronizedFilterInputStream.reset()