关于java:NettyUtils

import io.netty.buffer.ByteBuf;import static io.netty.buffer.ByteBufUtil.appendPrettyHexDump;import static io.netty.util.internal.StringUtil.NEWLINE;public class NettyUtils {    public static void log(ByteBuf buffer) {        int length = buffer.readableBytes();        int rows = length / 16 + (length % 15 == 0 ? 0 : 1) + 4;        StringBuilder buf = new StringBuilder(rows * 80 * 2)                .append("read index:").append(buffer.readerIndex())                .append(" write index:").append(buffer.writerIndex())                .append(" capacity:").append(buffer.capacity())                .append(NEWLINE);        appendPrettyHexDump(buf, buffer);        System.out.println(buf.toString());    }}