springboot整合Canal实时同步数据库表

╰半夏微凉° 2024-03-31 17:34 135阅读 0赞

![1f32d9da520a01be75ed966213e956a1.png][]

## 一、Canal介绍 ##

### 1、应用场景 ###

在前面的统计分析功能中，我们采取了服务调用获取统计数据，这样耦合度高，效率相对较低，目前我采取另一种实现方式，通过实时同步数据库表的方式实现，例如我们要统计每天注册与登录人数，我们只需把会员表同步到统计库中，实现本地统计就可以了，这样效率更高，耦合度更低，Canal就是一个很好的数据库同步工具。canal是阿里巴巴旗下的一款开源项目，纯Java开发。基于数据库增量日志解析，提供增量数据订阅&消费，目前主要支持了MySQL。

### **2、Canal环境搭建** ###

**canal的原理是基于mysql binlog技术，所以这里一定需要开启mysql的binlog写入功能**

**开启mysql服务：** service mysql start

#### **（1）检查binlog功能是否有开启** ####

![36e1bd95976b9646d624670f657ef27b.png][]

#### **（2）如果显示状态为OFF表示该功能未开启，开启binlog功能** ####

![3a16385c7f33f9618933d7d5074e395a.png][]

#### **（3）在mysql里面添加以下的相关用户和权限** ####

### 3、下载安装Canal服务 ###

下载地址： [https://github.com/alibaba/canal/releases][https_github.com_alibaba_canal_releases]

#### **（1）下载之后，放到目录中，解压文件** ####

cd /usr/local/canal

canal.deployer-1.1.4.tar.gz

tar zxvf canal.deployer-1.1.4.tar.gz

#### **（2）修改配置文件** ####

vi conf/example/instance.properties

![9d1147b531f37afcad950b8fb801ff5a.png][]

注：  
mysql 数据解析关注的表，Perl正则表达式.  
多个正则之间以逗号(,)分隔，转义符需要双斜杠(\\)  
常见例子：

1.  所有表：. *or .*\\..\*
2.  canal schema下所有表： canal\\..\*
3.  canal下的以canal打头的表：canal\\.canal.\*
4.  canal schema下的一张表：canal.test1
5.  多个规则组合使用：canal\\..\*,mysql.test1,mysql.test2 (逗号分隔)  
    注意：此过滤条件只针对row模式的数据有效(ps. mixed/statement因为不解析sql，所以无法准确提取tableName进行过滤)

（3）进入bin目录下启动  
sh bin/startup.sh

## **二、创建canal\_client模块** ##

### **1、****创建canal\_client模块** ###

![e332ffbfec7528eefe4b3d33bdcbe51a.png][]

### 2、引入相关依赖 ###

<dependencies>
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-web</artifactId>
            </dependency>
    
            
            <dependency>
                <groupId>mysql</groupId>
                <artifactId>mysql-connector-java</artifactId>
            </dependency>
    
            <dependency>
                <groupId>commons-dbutils</groupId>
                <artifactId>commons-dbutils</artifactId>
            </dependency>
    
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-jdbc</artifactId>
            </dependency>
    
            <dependency>
                <groupId>com.alibaba.otter</groupId>
                <artifactId>canal.client</artifactId>
            </dependency>
        </dependencies>

### 3、创建application.yml配置文件 ###

server:
      port: 8009
    spring:
      application:
        name: caner_clientedu
      profiles:
        active: dev
      datasource:
        driver-class-name: com.mysql.cj.jdbc.Driver
        url: jdbc:mysql://localhost:3306/education?serverTimezone=Asia/Shanghai&useUnicode=true&characterEncoding=utf-8&zeroDateTimeBehavior=convertToNull&useSSL=false&allowPublicKeyRetrieval=true
        username: root
        password: 419520

### 4、编写canal客户端类 ###

package com.xingchen.canel.client;
    
    
    
    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 org.apache.commons.dbutils.DbUtils;
    import org.apache.commons.dbutils.QueryRunner;
    import org.springframework.stereotype.Component;
    
    import javax.annotation.Resource;
    import javax.sql.DataSource;
    import java.net.InetSocketAddress;
    import java.sql.Connection;
    import java.sql.SQLException;
    import java.util.List;
    import java.util.Queue;
    import java.util.concurrent.ConcurrentLinkedQueue;
    
    
    @Component
    public class CanalClient {
    
        //sql队列
        private Queue<String> SQL_QUEUE = new ConcurrentLinkedQueue<>();
    
        @Resource
        private DataSource dataSource;
    
        /**
         * canal入库方法
         */
        public void run() {
    
            CanalConnector connector = CanalConnectors.newSingleConnector(new InetSocketAddress("192.168.88.135",
                    11111), "example", "", "");
            int batchSize = 1000;
            try {
                connector.connect();
                connector.subscribe(".*\\..*");
                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) {
                            Thread.sleep(1000);
                        } else {
                            dataHandle(message.getEntries());
                        }
                        connector.ack(batchId);
    
                        //当队列里面堆积的sql大于一定数值的时候就模拟执行
                        if (SQL_QUEUE.size() >= 1) {
                            executeQueueSql();
                        }
                    }
                } catch (InterruptedException e) {
                    e.printStackTrace();
                } catch (InvalidProtocolBufferException e) {
                    e.printStackTrace();
                }
            } finally {
                connector.disconnect();
            }
        }
    
        /**
         * 模拟执行队列里面的sql语句
         */
        public void executeQueueSql() {
            int size = SQL_QUEUE.size();
            for (int i = 0; i < size; i++) {
                String sql = SQL_QUEUE.poll();
                System.out.println("[sql]----> " + sql);
    
                this.execute(sql.toString());
            }
        }
    
        /**
         * 数据处理
         *
         * @param entrys
         */
        private void dataHandle(List<Entry> entrys) throws InvalidProtocolBufferException {
            for (Entry entry : entrys) {
                if (EntryType.ROWDATA == entry.getEntryType()) {
                    RowChange rowChange = RowChange.parseFrom(entry.getStoreValue());
                    EventType eventType = rowChange.getEventType();
                    if (eventType == EventType.DELETE) {
                        saveDeleteSql(entry);
                    } else if (eventType == EventType.UPDATE) {
                        saveUpdateSql(entry);
                    } else if (eventType == EventType.INSERT) {
                        saveInsertSql(entry);
                    }
                }
            }
        }
    
        /**
         * 保存更新语句
         *
         * @param entry
         */
        private void saveUpdateSql(Entry entry) {
            try {
                RowChange rowChange = RowChange.parseFrom(entry.getStoreValue());
                List<RowData> rowDatasList = rowChange.getRowDatasList();
                for (RowData rowData : rowDatasList) {
                    List<Column> newColumnList = rowData.getAfterColumnsList();
                    StringBuffer sql = new StringBuffer("update " + entry.getHeader().getTableName() + " set ");
                    for (int i = 0; i < newColumnList.size(); i++) {
                        sql.append(" " + newColumnList.get(i).getName()
                                + " = '" + newColumnList.get(i).getValue() + "'");
                        if (i != newColumnList.size() - 1) {
                            sql.append(",");
                        }
                    }
                    sql.append(" where ");
                    List<Column> oldColumnList = rowData.getBeforeColumnsList();
                    for (Column column : oldColumnList) {
                        if (column.getIsKey()) {
                            //暂时只支持单一主键
                            sql.append(column.getName() + "=" + column.getValue());
                            break;
                        }
                    }
                    SQL_QUEUE.add(sql.toString());
                }
            } catch (InvalidProtocolBufferException e) {
                e.printStackTrace();
            }
        }
    
        /**
         * 保存删除语句
         *
         * @param entry
         */
        private void saveDeleteSql(Entry entry) {
            try {
                RowChange rowChange = RowChange.parseFrom(entry.getStoreValue());
                List<RowData> rowDatasList = rowChange.getRowDatasList();
                for (RowData rowData : rowDatasList) {
                    List<Column> columnList = rowData.getBeforeColumnsList();
                    StringBuffer sql = new StringBuffer("delete from " + entry.getHeader().getTableName() + " where ");
                    for (Column column : columnList) {
                        if (column.getIsKey()) {
                            //暂时只支持单一主键
                            sql.append(column.getName() + "=" + column.getValue());
                            break;
                        }
                    }
                    SQL_QUEUE.add(sql.toString());
                }
            } catch (InvalidProtocolBufferException e) {
                e.printStackTrace();
            }
        }
    
        /**
         * 保存插入语句
         *
         * @param entry
         */
        private void saveInsertSql(Entry entry) {
            try {
                RowChange rowChange = RowChange.parseFrom(entry.getStoreValue());
                List<RowData> rowDatasList = rowChange.getRowDatasList();
                for (RowData rowData : rowDatasList) {
                    List<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(")");
                    SQL_QUEUE.add(sql.toString());
                }
            } catch (InvalidProtocolBufferException e) {
                e.printStackTrace();
            }
        }
    
        /**
         * 入库
         * @param sql
         */
        public void execute(String sql) {
            Connection con = null;
            try {
                if(null == sql) return;
                con = dataSource.getConnection();
                QueryRunner qr = new QueryRunner();
                int row = qr.execute(con, sql);
                System.out.println("update: "+ row);
            } catch (SQLException e) {
                e.printStackTrace();
            } finally {
                DbUtils.closeQuietly(con);
            }
        }
    }

### 5、创建启动类 ###

package com.xingchen.canel;
    
    
    
    import com.xingchen.canel.client.CanalClient;
    import org.springframework.boot.CommandLineRunner;
    import org.springframework.boot.SpringApplication;
    import org.springframework.boot.autoconfigure.SpringBootApplication;
    
    import javax.annotation.Resource;
    
    @SpringBootApplication
    public class CanalApplication implements CommandLineRunner{
        @Resource
        private CanalClient canalClient;
    
        public static void main(String[] args) {
            SpringApplication.run(CanalApplication.class, args);
        }
    
        @Override
        public void run(String... args) throws Exception {
            canalClient.run();
        }
    
    
    }

[1f32d9da520a01be75ed966213e956a1.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/31/d8a174ce76b04237baaddc01714dc77f.png
[36e1bd95976b9646d624670f657ef27b.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/31/25e6b6d02baf47f29f38e41a85adb8f3.png
[3a16385c7f33f9618933d7d5074e395a.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/31/4b10b976437d41409d9d3efd63c6a92b.png
[https_github.com_alibaba_canal_releases]: https://github.com/alibaba/canal/releases
[9d1147b531f37afcad950b8fb801ff5a.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/31/c64563ce80b641e09a52826e260a6ba4.png
[e332ffbfec7528eefe4b3d33bdcbe51a.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/31/51e6f234249d4beb8d303e7b3e4737ad.png