package com.alibaba.otter.canal.parse.driver.mysql.utils;

import java.io.IOException;
import java.nio.ByteBuffer;

import com.alibaba.otter.canal.parse.driver.mysql.packets.HeaderPacket;
import com.alibaba.otter.canal.parse.driver.mysql.socket.SocketChannel;

public abstract class PacketManager {

    public static HeaderPacket readHeader(SocketChannel ch, int len) throws IOException {
        HeaderPacket header = new HeaderPacket();
        header.fromBytes(readBytesAsBuffer(ch, len).array());
        return header;
    }

    public static ByteBuffer readBytesAsBuffer(SocketChannel ch, int len) throws IOException {
        ByteBuffer buffer = ByteBuffer.allocate(len);
        while (buffer.hasRemaining()) {
            int readNum = ch.read(buffer);
            if (readNum == -1) {
                throw new IOException("Unexpected End Stream");
            }
        }
        return buffer;
    }

    public static byte[] readBytes(SocketChannel ch, int len) throws IOException {
        return readBytesAsBuffer(ch, len).array();
    }

    /**
     * Since We r using blocking IO, so we will just write once and assert the
     * length to simplify the read operation.<br>
     * If the block write doesn't work as we expected, we will change this
     * implementation as per the result.
     * 
     * @param ch
     * @param len
     * @return
     * @throws IOException
     */
    public static void write(SocketChannel ch, byte[]... srcs) throws IOException {
        ch.writeChannel(srcs);
    }

    public static void write(SocketChannel ch, byte[] body) throws IOException {
        write(ch, body, (byte) 0);
    }

    public static void write(SocketChannel ch, byte[] body, byte packetSeqNumber) throws IOException {
        HeaderPacket header = new HeaderPacket();
        header.setPacketBodyLength(body.length);
        header.setPacketSequenceNumber(packetSeqNumber);
        write(ch, header.toBytes(),body);
    }
}

package com.alibaba.otter.canal.parse.driver.mysql.utils;

import java.io.IOException;

import com.alibaba.otter.canal.parse.driver.mysql.packets.HeaderPacket;
import com.alibaba.otter.canal.parse.driver.mysql.socket.SocketChannel;

public abstract class PacketManager {

    public static HeaderPacket readHeader(SocketChannel ch, int len) throws IOException {
        HeaderPacket header = new HeaderPacket();
        header.fromBytes(ch.read(len));
        return header;
    }

    public static byte[] readBytes(SocketChannel ch, int len) throws IOException {
        return ch.read(len);
    }

    public static void writePkg(SocketChannel ch, byte[]... srcs) throws IOException {
        ch.writeChannel(srcs);
    }
    
    public static void writeBody(SocketChannel ch, byte[] body) throws IOException {
    	writeBody0(ch, body, (byte) 0);
    }

    public static void writeBody0(SocketChannel ch, byte[] body, byte packetSeqNumber) throws IOException {
        HeaderPacket header = new HeaderPacket();
        header.setPacketBodyLength(body.length);
        header.setPacketSequenceNumber(packetSeqNumber);
        ch.writeChannel(header.toBytes(),body);
    }
}

Update PacketManager.java