mysql 协议的ResultsetRow包及解析

git

https://github.com/sea-boat/mysql-protocol

概况

ResultsetRow包属于服务端返回ResultSet时的其中一部分包，用于描述结果集的行记录。

mysql通信报文结构

ResultsetRow包

Payload

if(NULL){
  0xfb
}else{
  Protocol::LengthEncodedString
}

更多详情 ： http://dev.mysql.com/doc/internals/en/com-query-response.html#text-resultset

ResultsetRow包类

/**
 *
 * <pre><b>resultset row packet.</b></pre>
 * @author
 * <pre>seaboat</pre>
 * <pre><b>email: </b>849586227@qq.com</pre>
 * <pre><b>blog: </b>http://blog.csdn.net/wangyangzhizhou</pre>
 * @version 1.0
 * @see http://dev.mysql.com/doc/internals/en/com-query-response.html#text-resultset
 */
public class ResultsetRowPacket extends MySQLPacket {
    private static final byte NULL_MARK = (byte) 251;
    public int columnCount;
    public List<byte[]> columnValues;

    public ResultsetRowPacket() {

    }

    public ResultsetRowPacket(int columnCount) {
        this.columnCount = columnCount;
    }

    @Override
    public void read(byte[] data) {
        MySQLMessage mm = new MySQLMessage(data);
        packetLength = mm.readUB3();
        packetId = mm.read();
        for (int i = 0; i < columnCount; i++) {
            columnValues.add(mm.readBytesWithLength());
        }
    }

    @Override
    public void write(ByteBuffer buffer) {
        BufferUtil.writeUB3(buffer, calcPacketSize());
        buffer.put(packetId);
        for (int i = 0; i < columnCount; i++) {
            byte[] fv = columnValues.get(i);
            if (fv == null) {
                buffer.put(NULL_MARK);
            } else {
                BufferUtil.writeLength(buffer, fv.length);
                buffer.put(fv);
            }
        }
    }

    @Override
    public int calcPacketSize() {
        int size = 0;
        for (int i = 0; i < columnCount; i++) {
            byte[] v = columnValues.get(i);
            size += (v == null || v.length == 0) ? 1 : BufferUtil.getLength(v);
        }
        return size;
    }

    @Override
    protected String getPacketInfo() {
        return "MySQL Resultset Row Packet";
    }

}

========广告时间========

鄙人的新书《Tomcat内核设计剖析》已经在京东销售了，有需要的朋友可以到 https://item.jd.com/12185360.html 进行预定。感谢各位朋友。

为什么写《Tomcat内核设计剖析》

=========================