[Java知识库]1. SpringBoot 整合 Canal

勿以恶小而为之，勿以善小而不为----- 刘备

SpringBoot 整合 Canal

pom.xml 添加 canal.client 依赖

(1.1.5 改动很大，这儿客户端用 1.1.4)

<?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>2.2.2.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>top.yueshushu</groupId>
    <artifactId>learn</artifactId>
    <version>1.0-SNAPSHOT</version>
    <name>Canal</name>
    <description>学习 Canal</description>
    <properties>
        <java.version>1.8</java.version>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
        </dependency>
        <!-- 导入配置文件处理器，配置文件进行绑定就会有提示，需要重启 -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-configuration-processor</artifactId>
            <optional>true</optional>
        </dependency>
        <!--导入自动热步署的依赖-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
            <optional>true</optional>
        </dependency>
        <!--引入MySql的驱动-->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
        </dependency>
        <!--引入springboot与mybatis整合的依赖-->
        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>2.1.4</version>
        </dependency>
        <!-- 引入pagehelper分页插件 -->
        <dependency>
            <groupId>com.github.pagehelper</groupId>
            <artifactId>pagehelper-spring-boot-starter</artifactId>
            <version>1.2.5</version>
        </dependency>
        <!--添加 druid-spring-boot-starter的依赖的依赖-->
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid-spring-boot-starter</artifactId>
            <version>1.1.14</version>
        </dependency>
        <!--SpringBoot 的aop 模块-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-aop</artifactId>
        </dependency>

        <!--添加canal的依赖. 重要.  使用  1.1.4-->
        <dependency>
            <groupId>com.alibaba.otter</groupId>
            <artifactId>canal.client</artifactId>
            <version>1.1.4</version>
        </dependency>

        <dependency>
            <groupId>joda-time</groupId>
            <artifactId>joda-time</artifactId>
            <version>2.9.4</version>
        </dependency>
    </dependencies>
    <build>
        <!--将该目录下的文件全部打包成类的路径-->
        <resources>
            <resource>
                <directory>src/main/resources</directory>
            </resource>
        </resources>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>
</project>

业务功能处理

简单连接程序

/**
     * 一个简单的canal 的连接测试程序
     */
    @Test
    public void connectionTest() {
        //1. 创建连接  填充对应的地址信息 ,要监控的实例和相应的用户名和密码
        CanalConnector canalConnector = CanalConnectors.newSingleConnector(
                new InetSocketAddress(
                        "127.0.0.1", 11111
                ),
                "example",
                "canal",
                "canal"
        );
        //2. 进行连接
        canalConnector.connect();
        log.info(">>>连接成功:{}", canalConnector);
    }

17:26:32.179 [main] INFO top.yueshushu.learn.CanalDemoTest - >>>连接成功:com.alibaba.otter.canal.client.impl.SimpleCanalConnector@31ef45e3

单次获取数据

/**
     * 获取数据信息. 可以发现,未获取到数据 .  这个应该是实时的.
     */
    @Test
    public void getDataTest() {
        //1. 创建连接
        CanalConnector canalConnector = CanalConnectors.newSingleConnector(
                new InetSocketAddress("127.0.0.1", 11111),
                "example",
                "canal",
                "canal"
        );
        // 进行连接
        canalConnector.connect();

        //3. 注册,看使用哪个数据库表
        canalConnector.subscribe("springboot.user");

        //4. 获取 1条数据
        Message message = canalConnector.get(1);
        log.info("获取的数据:id:{},数据:{}", message.getId(), message);
        if (message.getId() == -1) {
            log.info(">>>未获取到数据");
            return;
        }
        //5. 获取相应的数据集合
        List<CanalEntry.Entry> entries = message.getEntries();
        for (CanalEntry.Entry entry : entries) {
            log.info(">>>获取数据 {}", entry);
            //获取表名
            CanalEntry.Header header = entry.getHeader();
            log.info(">>>获取表名:{}", header.getTableName());
            CanalEntry.EntryType entryType = entry.getEntryType();
            log.info(">>获取类型 {}:,对应的信息:{}", entryType.getNumber(), entryType.name());

            //获取数据
            ByteString storeValue = entry.getStoreValue();
            log.info(">>>输出存储的值:{}", storeValue);
        }
    }

在主库里面插入一条数据

insert into springboot.user(id,name,age,sex,description)  values(1,'canal添加用户',24,'男','学习canal');

再次执行:

循环获取数据

/**
     * 获取数据信息. 获取现在的数据.  再次执行时,就没有这个数据了.
     */
    @Test
    public void getNowDataTest() {
        //1. 创建连接
        CanalConnector canalConnector = CanalConnectors.newSingleConnector(
                new InetSocketAddress("127.0.0.1", 11111),
                "example",
                "canal",
                "canal"
        );
        // 进行连接
        canalConnector.connect();

        //3. 注册,看使用哪个数据库表
        canalConnector.subscribe("springboot.user");
        for (;;) {
            //4. 获取 1条数据
            Message message = canalConnector.get(1);
            log.info("获取的数据:id:{},数据:{}", message.getId(), message);
            if (message.getId() == -1) {
                log.info(">>>未获取到数据");
                try {
                    TimeUnit.MILLISECONDS.sleep(1000);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
                continue;
            }
            //5. 获取相应的数据集合
            List<CanalEntry.Entry> entries = message.getEntries();
            for (CanalEntry.Entry entry : entries) {
                log.info(">>>获取数据 {}", entry);
                //获取表名
                CanalEntry.Header header = entry.getHeader();
                log.info(">>>获取表名:{}", header.getTableName());
                CanalEntry.EntryType entryType = entry.getEntryType();
                log.info(">>获取类型 {}:,对应的信息:{}", entryType.getNumber(), entryType.name());

                //获取数据
                ByteString storeValue = entry.getStoreValue();
                log.info(">>>输出存储的值:{}", storeValue);
            }
        }
    }

可以随时获取相应的数据变更信息。
会发现， storeValue 的值是很难解读的。 需要将这个数据解析出来。

解析 storeValue 值

/**
     * 将 storeValue 进行解析,解析成我们能看懂的语句.
     * 对数据库 cud 进行处理操作观看一下.
     * 发现,点是不好的,也有多余的记录信息.
     *
     * @throws Exception 异常
     */
    @Test
    public void convertDataTest() throws Exception {
        //1. 创建连接
        CanalConnector canalConnector = CanalConnectors.newSingleConnector(
                new InetSocketAddress("127.0.0.1", 11111),
                "example",
                "canal", "canal"
        );
        //2. 进行连接
        canalConnector.connect();
        canalConnector.subscribe("springboot.user");

        for (;;) {
            //获取信息
            Message message = canalConnector.get(1);
            if (message.getId() == -1L) {
                // log.info("未获取到数据");
                try {
                    TimeUnit.MILLISECONDS.sleep(100);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
                continue;
            }
            List<CanalEntry.Entry> entryList = message.getEntries();
            //对获取到的数据进行处理
            log.info(">>获取到{}条数据", entryList.size());
            for (CanalEntry.Entry entry : entryList) {
                CanalEntry.Header header = entry.getHeader();
                log.info(">>>获取表名:{}", header.getTableName());
                //获取类型.
                CanalEntry.EntryType entryType = entry.getEntryType();
                log.info(">>类型编号 {},类型名称:{}", entryType.getNumber(), entryType.name());

                //获取存入日志的值
                ByteString storeValue = entry.getStoreValue();
                //将这个值进行解析
                CanalEntry.RowChange rowChange = RowChange.parseFrom(storeValue);
                String sql = rowChange.getSql();
                log.info(">>>获取对应的sql:{}", sql);
                // 这个sql 可能是 批量的sql语句
                List<CanalEntry.RowData> rowDatasList = rowChange.getRowDatasList();
                for (CanalEntry.RowData rowData : rowDatasList) {
                    log.info(">>>获取信息:{}", rowData);
                    //对数据进行处理
                    List<CanalEntry.Column> beforeColumnsList = rowData.getBeforeColumnsList();
                    List<CanalEntry.Column> afterColumnsList = rowData.getAfterColumnsList();

                    beforeColumnsList.forEach(
                            n -> log.info("哪个列{},原先是{},是否被更新{}", n.getName(),
                                    n.getValue(), n.getUpdated())
                    );
                    afterColumnsList.forEach(
                            n -> log.info("哪个列{},后来是{},是否被更新{}", n.getName(), n.getValue(), n.getUpdated())
                    );
                }
            }
        }

    }

再次执行sql

insert into springboot.user(id,name,age,sex,description) 
values(2,'canal添加用户2',25,'男','学习canal2');

不同的类型，进行不同的处理

发现 其他类型的 如: TRANSACTIONBEGIN 也进行了处理

/**
     * 类型转换数据
     *
     * @throws Exception 异常
     */
    @Test
    public void dataTypeTest() throws Exception {
        CanalConnector canalConnector = CanalConnectors.newSingleConnector(
                new InetSocketAddress(
                        "127.0.0.1", 11111
                ),
                "example",
                "canal", "canal"
        );
        canalConnector.connect();
        canalConnector.subscribe("springboot.user");

        for(;;){
            Message message = canalConnector.get(1);
            if (message.getId() == -1) {
                TimeUnit.SECONDS.sleep(1);
                continue;
            }

            List<CanalEntry.Entry> entries = message.getEntries();
            for (CanalEntry.Entry entry : entries) {
                CanalEntry.EntryType entryType = entry.getEntryType();
                //只要 RowData 数据类型的
                if (!CanalEntry.EntryType.ROWDATA.equals(entryType)) {
                    continue;
                }
                String tableName = entry.getHeader().getTableName();
                log.info(">>>对表 {} 进行操作", tableName);
                ByteString storeValue = entry.getStoreValue();
                RowChange rowChange = RowChange.parseFrom(storeValue);
                //行改变
                CanalEntry.EventType eventType = rowChange.getEventType();
                switch (eventType) {
                    case INSERT: {
                        insertHandler(rowChange);
                        break;
                    }
                    case UPDATE: {
                        updateHandler(rowChange);
                        break;
                    }
                    case DELETE: {
                        deleteHandler(rowChange);
                        break;
                    }
                    default: {
                        break;
                    }
                }
            }
        }

    }

    private void deleteHandler(RowChange rowChange) {
        log.info(">>>>执行删除的方法");
        List<CanalEntry.RowData> rowDatasList = rowChange.getRowDatasList();
        for (CanalEntry.RowData rowData : rowDatasList) {

            List<CanalEntry.Column> beforeColumnsList = rowData.getBeforeColumnsList();
            for (CanalEntry.Column column : beforeColumnsList) {

                log.info(">>>>>字段 {} 删除数据 {}", column.getName(), column.getValue());
            }
        }
    }

    private void updateHandler(RowChange rowChange) {
        log.info(">>>执行更新的方法");
        List<CanalEntry.RowData> rowDatasList = rowChange.getRowDatasList();
        for (CanalEntry.RowData rowData : rowDatasList) {

            List<CanalEntry.Column> beforeColumnsList = rowData.getBeforeColumnsList();
            List<CanalEntry.Column> afterColumnsList = rowData.getAfterColumnsList();
            Map<String, String> beforeValueMap = beforeColumnsList.stream().collect(
                    Collectors.toMap(
                            CanalEntry.Column::getName,
                            CanalEntry.Column::getValue
                    )
            );
            Map<String, String> afterValueMap = afterColumnsList.stream().collect(
                    Collectors.toMap(
                            CanalEntry.Column::getName,
                            CanalEntry.Column::getValue
                    )
            );
            beforeValueMap.forEach((column, beforeValue) -> {
                String afterValue = afterValueMap.get(column);
                Boolean update = beforeValue.equals(afterValue);
                log.info("修改列:{},修改前的值:{},修改后的值:{},是否更新:{}", column, beforeValue, afterValue,
                        update);
            });
        }

    }

    /**
     * 插入数据. 只有后的数据.
     *
     * @param rowChange 行改变
     */
    private void insertHandler(RowChange rowChange) {
        log.info(">>>执行添加 的方法");
        List<CanalEntry.RowData> rowDatasList = rowChange.getRowDatasList();
        for (CanalEntry.RowData rowData : rowDatasList) {
            List<CanalEntry.Column> afterColumnsList = rowData.getAfterColumnsList();

            for (CanalEntry.Column column : afterColumnsList) {
                if (!StringUtils.hasText(column.getValue())) {
                    continue;
                }
                log.info("字段 {} 插入了数据 {}", column.getName(), column.getValue());
            }

        }
    }

插入，更新，删除，分别进行了处理.
先启动测试程序:

不打印任何信息。
主表执行添加语句:

insert into springboot.user(id,name,age,sex,description) 
values(4,'canal添加用户4',25,'男','学习canal4');

会打印信息:

这个可读性就非常高了.

主表执行修改的操作.

update springboot.user set name='开开心心',age=26,description='岳泽霖' where id =4;

更新时，若每一个字段都跟原先一样，不会产生日志消费。

主表执行删除的操作:

delete from springboot.user where id =4;

上面的获取，都是一条数据一条数据获取的。效率比较低

一次性获取多条数据

/**
     * 一次性获取多条数据。
     * sql 执行多条。
     */
    @Test
    public void dataMoreTest() throws Exception {
        //1. 创建 canal连接对象
        CanalConnector canalConnector = CanalConnectors.newSingleConnector(
                new InetSocketAddress(
                        "127.0.0.1", 11111
                ),
                "example",
                "canal",
                "canal"
        );
        canalConnector.connect();
        // 订阅哪个对象
        canalConnector.subscribe("springboot.user");

        for (; ; ) {

           // Message message = canalConnector.get(3, 5L, TimeUnit.SECONDS);
            Message message = canalConnector.get(3);
            if (message.getId() == -1) {
                // 未获取到数据
                continue;
            }
            List<CanalEntry.Entry> entries = message.getEntries();
            for (CanalEntry.Entry entry : entries) {
                CanalEntry.EntryType entryType = entry.getEntryType();
                if (!CanalEntry.EntryType.ROWDATA.equals(entryType)) {
                    continue;
                }
                String tableName = entry.getHeader().getTableName();
                log.info(">>>>对表{} 执行操作", tableName);

                CanalEntry.RowChange rowChange = CanalEntry.RowChange.parseFrom(entry.getStoreValue());
                //对类型进行处理
                CanalEntry.EventType eventType = rowChange.getEventType();
                switch (eventType) {
                    case INSERT: {
                        insertHandler(rowChange);
                        break;
                    }
                    case UPDATE: {
                        updateHandler(rowChange);
                        break;
                    }
                    case DELETE: {
                        deleteHandler(rowChange);
                        break;
                    }
                    default: {
                        break;
                    }
                }

            }

        }
    }

    private void deleteHandler(CanalEntry.RowChange rowChange) {
        log.info(">>>>执行删除的方法");
        List<CanalEntry.RowData> rowDatasList = rowChange.getRowDatasList();
        for (CanalEntry.RowData rowData : rowDatasList) {

            List<CanalEntry.Column> beforeColumnsList = rowData.getBeforeColumnsList();
            for (CanalEntry.Column column : beforeColumnsList) {

                log.info(">>>>>字段 {} 删除数据 {}", column.getName(), column.getValue());
            }
        }
    }

    private void updateHandler(CanalEntry.RowChange rowChange) {
        log.info(">>>执行更新的方法");
        List<CanalEntry.RowData> rowDatasList = rowChange.getRowDatasList();
        for (CanalEntry.RowData rowData : rowDatasList) {

            List<CanalEntry.Column> beforeColumnsList = rowData.getBeforeColumnsList();
            List<CanalEntry.Column> afterColumnsList = rowData.getAfterColumnsList();
            Map<String, String> beforeValueMap = beforeColumnsList.stream().collect(
                    Collectors.toMap(
                            CanalEntry.Column::getName,
                            CanalEntry.Column::getValue
                    )
            );
            Map<String, String> afterValueMap = afterColumnsList.stream().collect(
                    Collectors.toMap(
                            CanalEntry.Column::getName,
                            CanalEntry.Column::getValue
                    )
            );
            beforeValueMap.forEach((column, beforeValue) -> {
                String afterValue = afterValueMap.get(column);
                Boolean update = beforeValue.equals(afterValue);
                log.info("修改列:{},修改前的值:{},修改后的值:{},是否更新:{}", column, beforeValue, afterValue,
                        update);
            });
        }

    }

    /**
     * 插入数据. 只有后的数据.
     *
     * @param rowChange 行改变
     */
    private void insertHandler(CanalEntry.RowChange rowChange) {
        log.info(">>>执行添加 的方法");
        List<CanalEntry.RowData> rowDatasList = rowChange.getRowDatasList();
        for (CanalEntry.RowData rowData : rowDatasList) {
            List<CanalEntry.Column> afterColumnsList = rowData.getAfterColumnsList();

            for (CanalEntry.Column column : afterColumnsList) {
                if (!StringUtils.hasText(column.getValue())) {
                    continue;
                }
                log.info("字段 {} 插入了数据 {}", column.getName(), column.getValue());
            }

        }
    }

修改点:

// Message message = canalConnector.get(3, 5L, TimeUnit.SECONDS);
    Message message = canalConnector.get(3);

.get(3) 表示 一次性获取3条记录.

canalConnector.get(3, 5L, TimeUnit.SECONDS); 表示5秒之内获取3条记录，
有两个触发条件，一个是获取了3条，一个是到了5秒。
效果展示信息与之前是一致的，就不重新演示了。

ack 配置信息

/**
     * 一次性获取多条数据。
     * sql 执行多条。 
     */
    @Test
    public void dataMoreTest() throws Exception {
        //1. 创建 canal连接对象
        CanalConnector canalConnector = CanalConnectors.newSingleConnector(
                new InetSocketAddress(
                        "127.0.0.1", 11111
                ),
                "example",
                "canal",
                "canal"
        );
        canalConnector.connect();
        // 订阅哪个对象
        canalConnector.subscribe("springboot.user");

        for (; ; ) {

             Message message = canalConnector.getWithoutAck(3, 2L, TimeUnit.SECONDS);
            if (message.getId() == -1) {
                // 未获取到数据
                TimeUnit.MILLISECONDS.sleep(500);
                continue;
            }
            log.info(">>>>获取对应的 id: {}",message.getId());
            List<CanalEntry.Entry> entries = message.getEntries();
            for (CanalEntry.Entry entry : entries) {
                CanalEntry.EntryType entryType = entry.getEntryType();
                if (!CanalEntry.EntryType.ROWDATA.equals(entryType)) {
                    continue;
                }
                String tableName = entry.getHeader().getTableName();
                log.info(">>>>对表{} 执行操作", tableName);

                CanalEntry.RowChange rowChange = CanalEntry.RowChange.parseFrom(entry.getStoreValue());
                //对类型进行处理
                CanalEntry.EventType eventType = rowChange.getEventType();
                switch (eventType) {
                    case INSERT: {
                        insertHandler(rowChange);
                        break;
                    }
                    case UPDATE: {
                        updateHandler(rowChange);
                        break;
                    }
                    case DELETE: {
                        deleteHandler(rowChange);
                        break;
                    }
                    default: {
                        break;
                    }
                }

            }
            //进行回滚
           // canalConnector.rollback();

            //确认ack 配置
           canalConnector.ack(message.getId());
        }
    }

    private void deleteHandler(CanalEntry.RowChange rowChange) {
        log.info(">>>>执行删除的方法");
        List<CanalEntry.RowData> rowDatasList = rowChange.getRowDatasList();
        for (CanalEntry.RowData rowData : rowDatasList) {

            List<CanalEntry.Column> beforeColumnsList = rowData.getBeforeColumnsList();
            for (CanalEntry.Column column : beforeColumnsList) {

                log.info(">>>>>字段 {} 删除数据 {}", column.getName(), column.getValue());
            }
        }
    }

    private void updateHandler(CanalEntry.RowChange rowChange) {
        log.info(">>>执行更新的方法");
        List<CanalEntry.RowData> rowDatasList = rowChange.getRowDatasList();
        for (CanalEntry.RowData rowData : rowDatasList) {

            List<CanalEntry.Column> beforeColumnsList = rowData.getBeforeColumnsList();
            List<CanalEntry.Column> afterColumnsList = rowData.getAfterColumnsList();
            Map<String, String> beforeValueMap = beforeColumnsList.stream().collect(
                    Collectors.toMap(
                            CanalEntry.Column::getName,
                            CanalEntry.Column::getValue
                    )
            );
            Map<String, String> afterValueMap = afterColumnsList.stream().collect(
                    Collectors.toMap(
                            CanalEntry.Column::getName,
                            CanalEntry.Column::getValue
                    )
            );
            beforeValueMap.forEach((column, beforeValue) -> {
                String afterValue = afterValueMap.get(column);
                Boolean update = beforeValue.equals(afterValue);
                log.info("修改列:{},修改前的值:{},修改后的值:{},是否更新:{}", column, beforeValue, afterValue,
                        update);
            });
        }

    }

    /**
     * 插入数据. 只有后的数据.
     *
     * @param rowChange 行改变
     */
    private void insertHandler(CanalEntry.RowChange rowChange) {
        log.info(">>>执行添加 的方法");
        List<CanalEntry.RowData> rowDatasList = rowChange.getRowDatasList();
        for (CanalEntry.RowData rowData : rowDatasList) {
            List<CanalEntry.Column> afterColumnsList = rowData.getAfterColumnsList();

            for (CanalEntry.Column column : afterColumnsList) {
                if (!StringUtils.hasText(column.getValue())) {
                    continue;
                }
                log.info("字段 {} 插入了数据 {}", column.getName(), column.getValue());
            }

        }
    }

主要信息:
Message message = canalConnector.getWithoutAck(3, 2L, TimeUnit.SECONDS);
//进行回滚 // canalConnector.rollback();
//确认ack 配置canalConnector.ack(message.getId());
手动确认消息消费了.
当消息 rollback() 回滚后，会再次消费这条消息.
canalConnector.rollback();
执行语句:

insert into springboot.user(id,name,age,sex,description) 
values(5,'canal添加用户5',25,'男','学习canal5');

如果变成 手动确认，
canalConnector.ack(message.getId());
则只消费一次.