android/guava/src/com/google/common/io/ByteSource.java
public byte[] read() throws IOException {
    Closer closer = Closer.create();
    try {
      InputStream in = closer.register(openStream());
      Optional<Long> size = sizeIfKnown();
      return size.isPresent()
          ? ByteStreams.toByteArray(in, size.get())
          : ByteStreams.toByteArray(in);
    } catch (Throwable e) {
      throw closer.rethrow(e);
    } finally {
      closer.close();
    }
  }
public byte[] read() throws IOException {
    Closer closer = Closer.create();
    try {
      InputStream in = closer.register(openStream());
      Optional<Long> size = sizeIfKnown();
      return size.isPresent()
          ? ByteStreams.toByteArray(in, size.get())
          : ByteStreams.toByteArray(in);
    } catch (Throwable e) {
      throw closer.rethrow(e);
    } finally {
      closer.close();
    }
  }
Reads the full contents of this byte source as a byte array.

@throws IOException if an I/O error occurs while reading from this source