Mysql 具体的协议格式

git

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

 

格式介绍

https://dev.mysql.com/doc/internals/en/overview.html

概况

mysql客户端与mysql服务端交互过程中，当服务端完成客户端的某命令时则会返回OK包。

mysql通信报文结构

类型	名字	描述
int<3>	payload长度	按照the least significant byte first存储，3个字节的payload和1个字节的序列号组合成报文头
int<1>	序列号
string	payload	报文体，长度即为前面指定的payload长度

OK包

Payload

Type	Name	Description
int<1>	header	[00] or [fe] the OK packet header
int	affected_rows	affected rows
int	last_insert_id	last insert-id
	if capabilities & CLIENT_PROTOCOL_41 {
int<2>	status_flags	Status Flags
int<2>	warnings	number of warnings
	}elseif capabilities & CLIENT_TRANSACTIONS {
int<2>	status_flags	Status Flags
	}
	if capabilities & CLIENT_SESSION_TRACK {
string	info	human readable status information
	if status_flags & SERVER_SESSION_STATE_CHANGED
string	session_state_changes	session state info
	}
	} else {
string	info	human readable status information
	}

更多详情 ： http://dev.mysql.com/doc/internals/en/packet-OK_Packet.html

Status Flags

Flag	Value
SERVER_STATUS_IN_TRANS	0x0001
SERVER_STATUS_AUTOCOMMIT	0x0002
SERVER_MORE_RESULTS_EXISTS	0x0008
SERVER_STATUS_NO_GOOD_INDEX_USED	0x0010
SERVER_STATUS_NO_INDEX_USED	0x0020
SERVER_STATUS_CURSOR_EXISTS	0x0040
SERVER_STATUS_LAST_ROW_SENT	0x0080
SERVER_STATUS_DB_DROPPED	0x0100
SERVER_STATUS_NO_BACKSLASH_ESCAPES	0x0200
SERVER_STATUS_METADATA_CHANGED	0x0400
SERVER_QUERY_WAS_SLOW	0x0800
SERVER_PS_OUT_PARAMS	0x1000
SERVER_STATUS_IN_TRANS_READONLY	0x2000
SERVER_SESSION_STATE_CHANGED	0x4000

OK包操作

1. OK包类

/**
 * 
 * @author seaboat
 * @date 2016-09-25
 * @version 1.0
 * <pre><b>email: </b>849586227@qq.com</pre>
 * <pre><b>blog: </b>http://blog.csdn.net/wangyangzhizhou</pre>
 * <p>mysql ok packet.</p>
 */
public class OKPacket extends MySQLPacket {
    public static final byte HEADER = 0x00;
    public static final byte[] OK = new byte[] { 7, 0, 0, 1, 0, 0, 0, 2, 0, 0,
            0 };

    public byte header = HEADER;
    public long affectedRows;
    public long insertId;
    public int serverStatus;
    public int warningCount;
    public byte[] message;

    public void read(byte[] data) {
        MySQLMessage mm = new MySQLMessage(data);
        packetLength = mm.readUB3();
        packetId = mm.read();
        header = mm.read();
        affectedRows = mm.readLength();
        insertId = mm.readLength();
        serverStatus = mm.readUB2();
        warningCount = mm.readUB2();
        if (mm.hasRemaining()) {
            this.message = mm.readBytesWithLength();
        }
    }

    public void write(ByteBuffer buffer) {
        BufferUtil.writeUB3(buffer, calcPacketSize());
        buffer.put(packetId);
        buffer.put(header);
        BufferUtil.writeLength(buffer, affectedRows);
        BufferUtil.writeLength(buffer, insertId);
        BufferUtil.writeUB2(buffer, serverStatus);
        BufferUtil.writeUB2(buffer, warningCount);
        if (message != null) {
            BufferUtil.writeWithLength(buffer, message);
        }
    }

    @Override
    public int calcPacketSize() {
        int i = 1;
        i += BufferUtil.getLength(affectedRows);
        i += BufferUtil.getLength(insertId);
        i += 4;
        if (message != null) {
            i += BufferUtil.getLength(message);
        }
        return i;
    }

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

}

 

1. 测试类

/**
 * 
 * @author seaboat
 * @date 2016-09-25
 * @version 1.0
 * <pre><b>email: </b>849586227@qq.com</pre>
 * <pre><b>blog: </b>http://blog.csdn.net/wangyangzhizhou</pre>
 * <p>test ok packet.</p>
 */
public class OKPacketTest {
    @Test
    public void produce() {
        OKPacket ok = new OKPacket();
        ok.packetId = 2;
        ok.affectedRows = 0;
        ok.insertId = 0;
        ok.serverStatus = 2;
        ok.warningCount = 0;
        ByteBuffer buffer = ByteBuffer.allocate(256);
        ok.write(buffer);
        buffer.flip();
        byte[] bytes = new byte[buffer.remaining()];
        buffer.get(bytes, 0, bytes.length);
        String result = HexUtil.Bytes2HexString(bytes);
        System.out.println(result);
        assertTrue(Integer.valueOf(result.substring(0, 2), 16) == result
                .length() / 2 - 4);

        OKPacket ok2 = new OKPacket();
        ok2.read(bytes);
        //auth ok
        assertTrue(result.equals("0700000200000002000000"));
    }

}

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