springboot整合canal，监听MySQL binlog日志，实现增量同步

有两个数据库，并不是主从关系，但是需要同步某张表，可以通过binlog日志，进行同步，前提是这两个数据库的要同步的表，表名和字段名需要一致。

当前项目连接的数据库（需要同步的数据库）：base_project

需要将数据同步到 base_project 的数据库（需要监听的数据库）：test

一、下载canal

我整合的是1.1.4版本，所以下载也是下载的1.1.4版本

解压，打开 conf/example/instance.properties 文件

#################################################
## mysql serverId , v1.0.26+ will autoGen
# canal.instance.mysql.slaveId=0

# enable gtid use true/false
canal.instance.gtidon=false

# 要监听的数据库ip地址和端口号，ip地址用真实ip，不要用localhost或127.0.0.1
canal.instance.master.address=192.168.0.111:3306 
# binlog的名称，canalv1.1.5不需要设置日志名称和偏移量，canal会自动识别
canal.instance.master.journal.name=binlog.000189
# 偏移量
canal.instance.master.position=
canal.instance.master.timestamp=
canal.instance.master.gtid=

# rds oss binlog
canal.instance.rds.accesskey=
canal.instance.rds.secretkey=
canal.instance.rds.instanceId=

# table meta tsdb info
canal.instance.tsdb.enable=false
#canal.instance.tsdb.url=jdbc:mysql://127.0.0.1:3306/canal_tsdb
#canal.instance.tsdb.dbUsername=canal
#canal.instance.tsdb.dbPassword=canal

#canal.instance.standby.address =
#canal.instance.standby.journal.name =
#canal.instance.standby.position =
#canal.instance.standby.timestamp =
#canal.instance.standby.gtid=

# username/password，MySQL服务器授权的账号密码
canal.instance.dbUsername=canal
canal.instance.dbPassword=canal
canal.instance.connectionCharset = UTF-8
# enable druid Decrypt database password
canal.instance.enableDruid=false
#canal.instance.pwdPublicKey=MFwwDQYJKoZIhvcNAQEBBQADSwAwSAJBALK4BUxdDltRRE5/zXpVEVPUgunvscYFtEip3pmLlhrWpacX7y7GCMo2/JM6LeHmiiNdH1FWgGCpUfircSwlWKUCAwEAAQ==

# table regex
canal.instance.filter.regex=test.customer,test.fault
# table black regex
canal.instance.filter.black.regex=
# table field filter(format: schema1.tableName1:field1/field2,schema2.tableName2:field1/field2)
#canal.instance.filter.field=test1.t_product:id/subject/keywords,test2.t_company:id/name/contact/ch
# table field black filter(format: schema1.tableName1:field1/field2,schema2.tableName2:field1/field2)
#canal.instance.filter.black.field=test1.t_product:subject/product_image,test2.t_company:id/name/contact/ch

# mq config
canal.mq.topic=example
# dynamic topic route by schema or table regex
#canal.mq.dynamicTopic=mytest1.user,mytest2\\..*,.*\\..*
canal.mq.partition=0
# hash partition config
#canal.mq.partitionsNum=3
#canal.mq.partitionHash=test.table:id^name,.*\\..*
#################################################

然后再打开 conf 下的 canal.properties 文件

# 找到下面这一句代码，这句代码默认是注释的，放开注释。如果不放开注释，可能在程序中就接收不到数据库的操作消息
# 如果放开了还是接收不到，可以试着把值调大一点
canal.instance.tsdb.snapshot.interval = 16

二、数据库配置

1、开启binlog

我的MySQL是8.0以上版本的，binlog是默认开启的，如果不知道是否开启的话，执行以下sql，value是ON说明是开启了，OFF是关闭状态，需要开启。

show variables like 'log_bin';

2、创建用户并授权

#创建用户canal，密码为canal，主机地址为192.168.0.111
create user canal@192.168.0.111 identified by 'canal';

#SHOW VIEW 查看视图，SELECT 查询，REPLICATION SLAVE、REPLICATION CLIENT 复制，*.* 表示所有库
GRANT SHOW VIEW, SELECT, REPLICATION SLAVE, REPLICATION CLIENT ON *.* TO 'canal'@192.168.0.111;

# 刷新
flush privileges;

3、设置binlog的模式为ROW

# 查看binlog的模式，如果value不是ROW，需要设置成ROW
show variables like 'binlog_format';
# 设置ROW
SET SESSION binlog_format = 'ROW';

三、启动canal

1、bin目录下，双击 startup.sh 启动

2、logs/canal 目录下，查看 canal.log，这个样子说明启动成功

3、logs/example 目录下，查看 example.log，这个样子没有报错就没问题

如果有 caching_sha2_password Auth failed 异常，则修改canal用户对应的身份验证插件为 mysql_native_password

java.net.ConnectException: Failed to connect to localhost/127.0.0.1 异常，需要将canal用户的主机localhost或127.0.0.1改为本机ip地址，配置文件的也要改。按照我的配置应该不会出现这个异常。

四、整合canal

1、pom.xml

<dependency>
    <groupId>com.alibaba.ottergroupId>
    <artifactId>canal.clientartifactId>
    <version>1.1.4version>
    
    <exclusions>
        <exclusion>
            <groupId>com.google.guavagroupId>
            <artifactId>guavaartifactId>
        exclusion>
    exclusions>
dependency>
<dependency>
    <groupId>commons-dbutilsgroupId>
    <artifactId>commons-dbutilsartifactId>
    <version>1.7version>
dependency>

2、yml

spring:
  datasource:
    url: jdbc:mysql://127.0.0.1:3306/base_project?useUnicode=true&characterEncoding=utf8&allowMultiQueries=true&useSSL=false&serverTimezone=GMT%2B8&allowPublicKeyRetrieval=true
    username: root
    password: root
    type: com.zaxxer.hikari.HikariDataSource
    driver-class-name: com.mysql.cj.jdbc.Driver
    
mybatis-plus:
  mapper-locations: classpath:mapper/*/*.xml
  type-aliases-package: com.entity.sys,;com.common.base
  global-config:
    db-config:
      id-type: auto
      field-strategy: NOT_EMPTY
      db-type: MYSQL
  configuration:
    map-underscore-to-camel-case: true
    call-setters-on-nulls: true
    log-impl: org.apache.ibatis.logging.stdout.StdOutImpl

canal-monitor-mysql:
  #要监听的数据库的主机地址，用具体的ip地址，不要用localhost或127.0.0.1
  hostname: "192.168.0.111"
  #canal端口号，这个是固定的：11111
  port: 11111
  #这个也是固定的
  example: "example"
  #要监听的数据库名和表名，这里我只监听用户表和部门表；指定多个表用逗号隔开
  #如果是监听数据库的全部表，用：test\\..*
  tableName: test.sys_user,test.sys_dept

3、CanalUtil

import cn.hutool.core.lang.Console;
import cn.hutool.core.util.StrUtil;
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.InvalidProtocolBufferException;
import com.mapper.pwjk.SqlMapper;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Component;

import javax.annotation.Resource;
import java.net.InetSocketAddress;
import java.util.List;

/**
 * @author Admin
 * 监听数据库binlog日志，实现监听的数据库和当前数据库增删改同步
 */
@Component
public class CanalUtil {

    /**
     * 要监听的数据库的主机地址
     */
    @Value("${canal-monitor-mysql.hostname}")
    private String canalMonitorHost;

    /**
     * canal端口号，这个是固定的用：11111
     */
    @Value("${canal-monitor-mysql.port}")
    private Integer canalMonitorPort;

    /**
     * canal的example，这个值是固定的用：example
     */
    @Value("${canal-monitor-mysql.example}")
    private String canalExample;

    /**
     * 要监听的数据库名和表名
     */
    @Value("${canal-monitor-mysql.tableName}")
    private String canalMonitorTableName;

    @Resource
    private SqlMapper sqlMapper;

    /**
     * canal入库方法
     */
    public void run() {
        CanalConnector connector = CanalConnectors.newSingleConnector(new InetSocketAddress(canalMonitorHost,canalMonitorPort), canalExample, "", "");
        int batchSize = 1000;
        try {
            connector.connect();
            Console.log("数据库检测连接成功：" + canalMonitorTableName);
            connector.subscribe(canalMonitorTableName);
            connector.rollback();
            try {
                while (true) {
                    //尝试从master那边拉去数据batchSize条记录，有多少取多少
                    Message message = connector.getWithoutAck(batchSize);
                    long batchId = message.getId();
                    int size = message.getEntries().size();
                    if (batchId == -1 || size == 0) {
                        //每隔一秒监听一次
                        Thread.sleep(1000);
                    } else {
                        dataHandle(message.getEntries());
                    }
                    connector.ack(batchId);
                }
            } catch (InterruptedException e) {
                e.printStackTrace();
            } catch (InvalidProtocolBufferException e) {
                e.printStackTrace();
            }
        } finally {
            connector.disconnect();
        }
    }

    /**
     * 数据处理
     */
    private void dataHandle(List<CanalEntry.Entry> entrys) throws InvalidProtocolBufferException {
        try {
            for (CanalEntry.Entry entry : entrys) {
                if (CanalEntry.EntryType.ROWDATA == entry.getEntryType()) {
                    CanalEntry.RowChange rowChange = CanalEntry.RowChange.parseFrom(entry.getStoreValue());
                    CanalEntry.EventType eventType = rowChange.getEventType();
                    if (eventType == CanalEntry.EventType.DELETE) {
                        //删除，返回删除的sql语句，然后在mapper中，直接执行这句sql
                        String sql = saveDeleteSql(entry);
                        if (StrUtil.isNotBlank(sql)){
                            sqlMapper.dynamicsDelete(sql);
                        }
                    } else if (eventType == CanalEntry.EventType.UPDATE) {
                        //更新，返回更新的sql语句，然后在mapper中，直接执行这句sql
                        String sql = saveUpdateSql(entry);
                        if (StrUtil.isNotBlank(sql)){
                            sqlMapper.dynamicsUpdate(sql);
                        }
                    } else if (eventType == CanalEntry.EventType.INSERT) {
                        //新增，返回新增的sql语句，然后在mapper中，直接执行这句sql
                        String sql = saveInsertSql(entry);
                        if (StrUtil.isNotBlank(sql)){
                            sqlMapper.dynamicsInsert(sql);
                        }
                    }
                }
            }
        }catch (Exception e){
            return;
        }
    }

    /**
     * 保存更新语句
     */
    private String saveUpdateSql(CanalEntry.Entry entry) {
        try {
            CanalEntry.RowChange rowChange = CanalEntry.RowChange.parseFrom(entry.getStoreValue());
            List<CanalEntry.RowData> rowDataList = rowChange.getRowDatasList();
            for (CanalEntry.RowData rowData : rowDataList) {
                List<CanalEntry.Column> newColumnList = rowData.getAfterColumnsList();
                StringBuffer sql = new StringBuffer("update " +  entry.getHeader().getTableName() + " set ");
                for (int i = 0; i < newColumnList.size(); i++) {
                    if (!newColumnList.get(i).getIsKey()) {
                        sql.append(" " + newColumnList.get(i).getName() + " = '" + newColumnList.get(i).getValue() + "'");
                        if (i != newColumnList.size() - 1) {
                            sql.append(",");
                        }
                    }
                }
                sql.append(" where ");
                List<CanalEntry.Column> oldColumnList = rowData.getBeforeColumnsList();
                for (CanalEntry.Column column : oldColumnList) {
                    if (column.getIsKey()) {
                        //暂时只支持单一主键
                        sql.append(column.getName() + "=" + column.getValue());
                        break;
                    }
                }
                return sql.toString();
            }
        } catch (InvalidProtocolBufferException e) {
            return null;
        }
        return null;
    }

    /**
     * 保存删除语句
     */
    private String saveDeleteSql(CanalEntry.Entry entry) {
        try {
            CanalEntry.RowChange rowChange = CanalEntry.RowChange.parseFrom(entry.getStoreValue());
            List<CanalEntry.RowData> rowDataList = rowChange.getRowDatasList();
            for (CanalEntry.RowData rowData : rowDataList) {
                List<CanalEntry.Column> columnList = rowData.getBeforeColumnsList();
                StringBuffer sql = new StringBuffer("delete from " + entry.getHeader().getTableName() + " where ");
                for (CanalEntry.Column column : columnList) {
                    if (column.getIsKey()) {
                        sql.append(column.getName() + "=" + column.getValue());
                        break;
                    }
                }
                return sql.toString();
            }
        } catch (InvalidProtocolBufferException e) {
            return null;
        }
        return null;
    }

    /**
     * 保存插入语句
     */
    private String saveInsertSql(CanalEntry.Entry entry) {
        try {
            CanalEntry.RowChange rowChange = CanalEntry.RowChange.parseFrom(entry.getStoreValue());
            List<CanalEntry.RowData> rowDataList = rowChange.getRowDatasList();
            for (CanalEntry.RowData rowData : rowDataList) {
                List<CanalEntry.Column> columnList = rowData.getAfterColumnsList();
                StringBuffer sql = new StringBuffer("insert into "+entry.getHeader().getTableName() + " (");
                for (int i = 0; i < columnList.size(); i++) {
                    sql.append(columnList.get(i).getName());
                    if (i != columnList.size() - 1) {
                        sql.append(",");
                    }
                }
                sql.append(") VALUES (");
                for (int i = 0; i < columnList.size(); i++) {
                    sql.append("'" + columnList.get(i).getValue() + "'");
                    if (i != columnList.size() - 1) {
                        sql.append(",");
                    }
                }
                sql.append(")");
                return sql.toString();
            }
        } catch (InvalidProtocolBufferException e) {
            return null;
        }
        return null;
    }
}

4、启动类

import com.common.util.CanalUtil;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.CommandLineRunner;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cache.annotation.EnableCaching;

import javax.annotation.Resource;

@SpringBootApplication
@MapperScan({"com.mapper.sys"})
@EnableCaching
public class BaseProjectApplication implements CommandLineRunner {

    @Resource
    private CanalUtil canalUtil;

    public static void main(String[] args) {
        SpringApplication.run(BaseProjectApplication.class, args);
    }

    @Override
    public void run(String... args){
        canalUtil.run();
    }
}

五、增量同步

1、新增 SqlMapper

import org.apache.ibatis.annotations.Param;

/**
 * @author Admin
 */
public interface SqlMapper {

    void dynamicsInsert(@Param("paramSQL") String sql);

    void dynamicsUpdate(@Param("paramSQL") String sql);

    void dynamicsDelete(@Param("paramSQL") String sql);
}

DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.mapper.sys.SqlMapper">

    <insert id="dynamicsInsert">
        ${paramSQL}
    insert>

    <update id="dynamicsUpdate">
        ${paramSQL}
    update>

    <delete id="dynamicsDelete">
        ${paramSQL}
    delete>

mapper>