手摸手实现Canal如何接入MySQL实现数据写操作监听

firewall‐cmd ‐‐zone=public ‐‐add‐port=3306/tcp ‐‐permanent
firewall‐cmd ‐‐reload

cd /home/
wget ‐‐no‐check‐certificate https://manongbiji.oss‐cn‐
beijing.aliyuncs.com/ittailkshow/canal/download/world.sql
wget ‐‐no‐check‐certificate https://repo.mysql.com/mysql80‐community‐releas
e‐el7‐5.noarch.rpm
yum localinstall ‐y mysql80‐community‐release‐el7‐5.noarch.rpm

#自动安装MySQL 8.0.28
yum install ‐y mysql‐community‐server

sudo cat >> /etc/my.cnf <<‐'EOF'
server‐id=1
log‐bin=mysql‐bin
binlog_format=row
binlog‐do‐db=world
EOF
systemctl start mysqld

grep 'temporary password' /var/log/mysqld.log
2022-03-31T04:20:25.133810Z 6 [Note] [MY-010454] [Server] A temporary password is
generated for root@localhost: Jby&XTOc.7iN
mysql ‐uroot ‐pJby&XTOc.7iN

#修改root密码
ALTER USER 'root'@'localhost' IDENTIFIED WITH mysql_native_password BY 'asA
S123456!';

#MySQL降低密码强度
set global validate_password.policy=0;
set global validate_password.length=4;

#创建canal同步账户
CREATE USER canal@'%' IDENTIFIED with mysql_native_password BY 'canal';

#授权canal用户允许远程到mysql实现主从复制
GRANT SELECT, REPLICATION SLAVE, REPLICATION CLIENT ON *.* TO 'canal'@'%';
CREATE USER remote@'%' IDENTIFIED with mysql_native_password BY 'remote';
grant all privileges on *.* to remote@'%';

#初始化数据库
source /home/world.sql

yum ‐y install java‐1.8.0‐openjdk‐devel.x86_64
sudo cat >> /etc/profile <<‐'EOF'
export JAVA_HOME=/usr/lib/jvm/java‐1.8.0‐openjdk
export JRE_HOME=$JAVA_HOME/jre
export CLASSPATH=$JAVA_HOME/lib:$JRE_HOME/lib:$CLASSPATH
export PATH=$JAVA_HOME/bin:$JRE_HOME/bin:$PATH
EOF
source /etc/profile
echo $JAVA_HOME

# 下载脚本
wget ‐‐no‐check‐certificate https://manongbiji.oss‐cn‐
beijing.aliyuncs.com/ittailkshow/canal/download/canal.deployer‐
1.1.5.tar.gz
mkdir /home/canal
tar zxvf canal.deployer‐1.1.5.tar.gz ‐C /home/canal

vi conf/example/instance.properties
#调整serverId
canal.instance.mysql.slaveId=10
# master地址
canal.instance.master.address=192.168.31.230:3306
...
# 关闭tsdb
canal.instance.tsdb.enable=false
#确认canal同步用的用户名、密码
canal.instance.dbUsername=canal
canal.instance.dbPassword=canal

#启动服务
sh bin/startup.sh
#canal admin 端口
开发数据监听程序
pom.xml
编写数据监听程序
firewall‐cmd ‐‐zone=public ‐‐add‐port=11110/tcp ‐‐permanent
#canal 监听端口
firewall‐cmd ‐‐zone=public ‐‐add‐port=11111/tcp ‐‐permanent
#canal 指标监控端口
firewall‐cmd ‐‐zone=public ‐‐add‐port=11112/tcp ‐‐permanent
firewall‐cmd ‐‐reload

<dependencies>
	<dependency>
		<groupId>com.alibaba.otter</groupId>
		<artifactId>canal.client</artifactId>
		<version>1.1.5</version>
	</dependency>
	<dependency>
		<groupId>com.alibaba.otter</groupId>
		<artifactId>canal.protocol</artifactId>
		<version>1.1.5</version>
	</dependency>
</dependencies>

package com.itlaoqi;
import com.alibaba.fastjson.JSONObject;
import com.alibaba.otter.canal.client.CanalConnector;
import com.alibaba.otter.canal.client.CanalConnectors;
import com.alibaba.otter.canal.protocol.CanalEntry;
import com.alibaba.otter.canal.protocol.Message;
import com.google.protobuf.ByteString;
import com.google.protobuf.InvalidProtocolBufferException;
import java.net.InetSocketAddress;
import java.util.List;
public class AD {
	public static void main(String[] args) throws InterruptedException, Invalid
	ProtocolBufferException {
		//TODO 获取连接
		CanalConnector canalConnector = CanalConnectors.newSingleConnector(new Inet
		SocketAddress("192.168.31.231", 11111), "example", "", "");
		while (true) {
			//TODO 连接
			canalConnector.connect();
			//TODO 订阅数据库
			canalConnector.subscribe("world.*");
			//TODO 获取数据
			Message message = canalConnector.get(100);
			//TODO 获取Entry集合
			List<CanalEntry.Entry> entries = message.getEntries();
			//TODO 判断集合是否为空,如果为空,则等待一会继续拉取数据
			if (entries.size() <= 0) {
				System.out.println("当次抓取没有数据，休息一会。。。。。。");
				Thread.sleep(1000);
			} else {
				//TODO 遍历entries，单条解析
				for (CanalEntry.Entry entry : entries) {
					//1.获取表名
					String tableName = entry.getHeader().getTableName();
					//2.获取类型
					CanalEntry.EntryType entryType = entry.getEntryType();
					//3.获取序列化后的数据
					ByteString storeValue = entry.getStoreValue();
					//4.判断当前entryType类型是否为ROWDATA
					if (CanalEntry.EntryType.ROWDATA.equals(entryType)) {
						//5.反序列化数据
						CanalEntry.RowChange rowChange =
						CanalEntry.RowChange.parseFrom(storeValue);
						//6.获取当前事件的操作类型
						CanalEntry.EventType eventType = rowChange.getEventType();
						//7.获取数据集
						List<CanalEntry.RowData> rowDataList = rowChange.getRowDatasList();
						//8.遍历rowDataList，并打印数据集
						for (CanalEntry.RowData rowData : rowDataList) {
							JSONObject beforeData = new JSONObject();
							List<CanalEntry.Column> beforeColumnsList = rowData.getBeforeColumnsList();
							for (CanalEntry.Column column : beforeColumnsList) {
								beforeData.put(column.getName(), column.getValue());
							}
							JSONObject afterData = new JSONObject();
							List<CanalEntry.Column> afterColumnsList = rowData.getAfterColumnsList();
							for (CanalEntry.Column column : afterColumnsList) {
								afterData.put(column.getName(), column.getValue());
							}
						//数据打印
							System.out.println("Table:" + tableName +
							",EventType:" + eventType +
							",Before:" + beforeData +
							",After:" + afterData);
						}
					} else {
						System.out.println("当前操作类型为：" + entryType);
					}
				}
			}
		}
	}
}