public List<ByteBuffer> getByteBuffers() {
    if (!this.lastBufFlipped) {
      this.lastBufFlipped = true;
      // All the other BBs are already flipped while moving to the new BB.
      curBuf.flip();
    }
    List<ByteBuffer> bbs = new ArrayList<>(this.allBufs.size());
    for (SingleByteBuff bb : this.allBufs) {
      bbs.add(bb.nioByteBuffers()[0]);
    }
    return bbs;
  }
We can be assured that the buffers returned by this method are all flipped
@return list of bytebuffers
hbase-common/src/main/java/org/apache/hadoop/hbase/io/ByteBufferListOutputStream.java