Method isEmpty

corpus/java/training/guava/io/ByteSource.java:138–152

Returns whether the source has zero bytes. The default implementation returns true if #sizeIfKnown returns zero, falling back to opening a stream and checking for EOF if the size is not known. Note that, in cases where sizeIfKnown returns zero, it is possible that bytes ar

()

   * @since 15.0
   */
  public boolean isEmpty() throws IOException {
    Optional<Long> sizeIfKnown = sizeIfKnown();
    if (sizeIfKnown.isPresent() && sizeIfKnown.get() == 0L) {
      return true;
    }
    Closer closer = Closer.create();
    try {
      InputStream in = closer.register(openStream());
      return in.read() == -1;
    } catch (Throwable e) {
      throw closer.rethrow(e);
    } finally {
      closer.close();
    }
  }

  /**
   * Returns the size of this source in bytes, if the size can be easily determined without actually