使用Canal实现MySQL主从同步

说明：本文介绍如何使用Canal实现MySQL主从同步的效果，关于Canal入门使用参考：Canal入门使用

启动Canal

首先，设置Canal服务器里，目标节点（即监测的MySQL节点）的配置，启动Canal服务；

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启动Canal服务器，Windows操作系统下，直接双击startup.bat文件即可；

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具体操作参考：Canal入门使用

创建项目

创建一个Spring Boot项目，pom.xml文件如下：

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"><modelVersion>4.0.0</modelVersion><parent><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-parent</artifactId><version>2.7.12</version><relativePath/></parent><groupId>com.hezy</groupId><artifactId>canal_demo</artifactId><version>1.0-SNAPSHOT</version><properties><maven.compiler.source>11</maven.compiler.source><maven.compiler.target>11</maven.compiler.target><project.build.sourceEncoding>UTF-8</project.build.sourceEncoding></properties><dependencies><!--lombok--><dependency><groupId>org.projectlombok</groupId><artifactId>lombok</artifactId></dependency><!--druid--><dependency><groupId>com.alibaba</groupId><artifactId>druid-spring-boot-starter</artifactId><version>1.2.8</version></dependency><!--mybatis--><dependency><groupId>org.mybatis.spring.boot</groupId><artifactId>mybatis-spring-boot-starter</artifactId><version>2.2.2</version></dependency><!--mysql驱动--><dependency><groupId>com.mysql</groupId><artifactId>mysql-connector-j</artifactId><scope>runtime</scope></dependency><!--canal客户端--><dependency><groupId>top.javatool</groupId><artifactId>canal-spring-boot-starter</artifactId><version>1.2.1-RELEASE</version></dependency></dependencies></project>

application.yml文件如下，这里的数据库配置写从节点的，且账户应该有数据读写权限；

server:port: 8080# 1.数据源的配置
spring:# 数据库配置datasource:driver-class-name: com.mysql.cj.jdbc.Driverurl: jdbc:mysql://从节点MySQLIP:3306/test?useUnicode=true&characterEncoding=utf-8&useSSL=falseusername: rootpassword: 123456# 2.mybatis配置
mybatis:configuration:# 显示SQL日志配置log-impl: org.apache.ibatis.logging.stdout.StdOutImpl# 驼峰命名配置map-underscore-to-camel-case: true# 3.canal配置
canal:# canal服务端的ipserver: 127.0.0.1:11111destination: example

实体类对象

import lombok.Data;import java.io.Serializable;@Data
public class User implements Serializable {private String id;private String username;private String password;
}

canal处理类

import com.hezy.mapper.UserMapper;
import com.hezy.pojo.User;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;
import top.javatool.canal.client.annotation.CanalTable;
import top.javatool.canal.client.handler.EntryHandler;@Component
@CanalTable("i_user")
public class UserHandler implements EntryHandler<User> {@Autowiredprivate UserMapper userMapper;@Overridepublic void insert(User user) {System.out.println("新增用户：" + user);userMapper.insertUser(user);}@Overridepublic void update(User before, User after) {System.out.println("更新用户：" + before + " -> " + after);userMapper.updateUserById(after);}@Overridepublic void delete(User user) {System.out.println("删除用户：" + user);userMapper.deleteUserById(user.getId());}
}

对应写三个针对User表（User实体类对应的表，即i_user表）操作的Mapper方法；

import com.hezy.pojo.User;
import org.apache.ibatis.annotations.Delete;
import org.apache.ibatis.annotations.Insert;
import org.apache.ibatis.annotations.Mapper;
import org.apache.ibatis.annotations.Update;@Mapper
public interface UserMapper {@Insert("insert into i_user values (#{id}, #{username}, #{password})")void insertUser(User uesr);@Delete("delete from i_user where id = #{id}")void deleteUserById(String id);@Update("update i_user set username=#{username}, password=#{password} where id=#{id}")void updateUserById(User user);}