final long fileSize = ChannelUtil.size(channel);

            if (fileSize > maxSize) {
                throw new IORuntimeException(new IOException("File too large: " + fileSize + " bytes (max: " + maxSize + " bytes). Use streaming APIs for large files."));
            }

            final ByteBuffer buffer = ByteBuffer.allocate((int) fileSize);
            ChannelUtil.read(channel, buffer);