Class ByteSource.SlicedByteSource

java.lang.Object
com.google.common.io.ByteSource
com.google.common.io.ByteSource.SlicedByteSource
Enclosing class:
ByteSource

private final class ByteSource.SlicedByteSource extends ByteSource
A view of a subsection of the containing byte source.
  • Field Details

    • offset

      final long offset
    • length

      final long length
  • Constructor Details

    • SlicedByteSource

      SlicedByteSource(long offset, long length)
  • Method Details

    • openStream

      public InputStream openStream() throws IOException
      Description copied from class: ByteSource
      Opens a new InputStream for reading from this source. This method returns a new, independent stream each time it is called.

      The caller is responsible for ensuring that the returned stream is closed.

      Specified by:
      openStream in class ByteSource
      Throws:
      IOException - if an I/O error occurs while opening the stream
    • openBufferedStream

      public InputStream openBufferedStream() throws IOException
      Description copied from class: ByteSource
      Opens a new buffered InputStream for reading from this source. The returned stream is not required to be a BufferedInputStream in order to allow implementations to simply delegate to ByteSource.openStream() when the stream returned by that method does not benefit from additional buffering (for example, a ByteArrayInputStream). This method returns a new, independent stream each time it is called.

      The caller is responsible for ensuring that the returned stream is closed.

      Overrides:
      openBufferedStream in class ByteSource
      Throws:
      IOException - if an I/O error occurs while opening the stream
    • sliceStream

      private InputStream sliceStream(InputStream in) throws IOException
      Throws:
      IOException
    • slice

      public ByteSource slice(long offset, long length)
      Description copied from class: ByteSource
      Returns a view of a slice of this byte source that is at most length bytes long starting at the given offset. If offset is greater than the size of this source, the returned source will be empty. If offset + length is greater than the size of this source, the returned source will contain the slice starting at offset and ending at the end of this source.
      Overrides:
      slice in class ByteSource
    • isEmpty

      public boolean isEmpty() throws IOException
      Description copied from class: ByteSource
      Returns whether the source has zero bytes. The default implementation first checks ByteSource.sizeIfKnown(), returning true if it's known to be zero and false if it's known to be non-zero. If the size is not known, it falls back to opening a stream and checking for EOF.

      Note that, in cases where sizeIfKnown returns zero, it is possible that bytes are actually available for reading. (For example, some special files may return a size of 0 despite actually having content when read.) This means that a source may return true from isEmpty() despite having readable content.

      Overrides:
      isEmpty in class ByteSource
      Throws:
      IOException - if an I/O error occurs
    • sizeIfKnown

      public Optional<Long> sizeIfKnown()
      Description copied from class: ByteSource
      Returns the size of this source in bytes, if the size can be easily determined without actually opening the data stream.

      The default implementation returns Optional.absent(). Some sources, such as a file, may return a non-absent value. Note that in such cases, it is possible that this method will return a different number of bytes than would be returned by reading all of the bytes (for example, some special files may return a size of 0 despite actually having content when read).

      Additionally, for mutable sources such as files, a subsequent read may return a different number of bytes if the contents are changed.

      Overrides:
      sizeIfKnown in class ByteSource
    • toString

      public String toString()
      Overrides:
      toString in class Object