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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
@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); }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
@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
@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
@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
@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); }); } } 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
@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); }); } } 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
@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); }); } } 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.
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