Package com.google.common.io

Class ByteSource.ConcatenatedByteSource

  • Enclosing class:
    ByteSource
    private static final class ByteSource.ConcatenatedByteSource
extends ByteSource

    • Field Detail

      • sources

        final java.lang.Iterable<? extends ByteSource> sources

    • Constructor Detail

      • ConcatenatedByteSource

        ConcatenatedByteSource​(java.lang.Iterable<? extends ByteSource> sources)

    • Method Detail

      • openStream

        public java.io.InputStream openStream()
                               throws java.io.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:
        java.io.IOException - if an I/O error occurs while opening the stream

      • isEmpty

        public boolean isEmpty()
                throws java.io.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:
        java.io.IOException - if an I/O error occurs

      • sizeIfKnown

        public Optional<java.lang.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

      • size

        public long size()
          throws java.io.IOException
        Description copied from class: ByteSource
        Returns the size of this source in bytes, even if doing so requires opening and traversing an entire stream. To avoid a potentially expensive operation, see ByteSource.sizeIfKnown().

        The default implementation calls ByteSource.sizeIfKnown() and returns the value if present. If absent, it will fall back to a heavyweight operation that will open a stream, read (or skip, if possible) to the end of the stream and return the total number of bytes that were read.

        Note that for some sources that implement ByteSource.sizeIfKnown() to provide a more efficient implementation, 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).

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

        Overrides:
        size in class ByteSource
        Throws:
        java.io.IOException - if an I/O error occurs while reading the size of this source

      • toString

        public java.lang.String toString()
        Overrides:
        toString in class java.lang.Object