Review

Misses to call ByteBuffer.flip() between writing to and reading from the buffer (or vice versa). There''s many ways to read/write buffer, some of which fail if flip() is missing, while others just do nothing. StackOverflow: http://stackoverflow.com/questions/10166011/how-to-use-java-nio-channels-filechannel-to-write-a-byte-to-a-file-basics/10166055

Add a call to ByteBuffer.flip()

• missing/call

ByteBufferFlip.java

misuse(byte[])

class ByteBufferFlip {
  public void misuse(byte[] result) throws IOException {
  		ByteBuffer buffer = ByteBuffer.allocate(result.length);
  		buffer.put(result);
  		// missing buffer.flip() for subsequent reading
		
  		Path fp = FileSystems.getDefault().getPath("output.file");
  		FileChannel outChannel = FileChannel
  				.open(fp, EnumSet.of(StandardOpenOption.CREATE,
  						StandardOpenOption.TRUNCATE_EXISTING,
  						StandardOpenOption.WRITE));

  		outChannel.write(buffer); // <-- reads buffer
  		outChannel.force(false);
  	}

}

public class FlipBuffer {
  public void pattern(byte[] content, FileChannel outChannel) throws IOException {
  	ByteBuffer buffer = ByteBuffer.allocate(content.length);
  	buffer.put(content);
  	buffer.flip(); // <-- required for subsequent reading
    outChannel.write(buffer); // reads buffer
  }
}