Canal 结合spring boot项目开发

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 Canal使用和安装总结 ： https://www.cnblogs.com/zjdxr-up/p/17977706

1.数据库准备

　　在数据库修改user表的数据，通过canal服务将数据库修改的数据同步到 java 的spring 服务中，以user表为例，以下为表结构和数据准备：

CREATE TABLE `user` (
  `id` bigint NOT NULL AUTO_INCREMENT,
  `name` varchar(255) DEFAULT NULL,
  `age` int DEFAULT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb3;

insert into user(name, age) values('dafei', 18);
insert into user(name, age) values('dafei', 18);
insert into user(name, age) values('dafei', 18);

2.在spring项目中导入相关依赖：

<parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-parent</artifactId>
    <version>2.7.11</version>
</parent>

<dependencies>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter</artifactId>
    </dependency>
    <dependency>
        <groupId>top.javatool</groupId>
        <artifactId>canal-spring-boot-starter</artifactId>
        <version>1.2.6-RELEASE</version>
    </dependency>
    <dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
        <version>8.0.12</version>
    </dependency>
    <dependency>
        <groupId>com.google.protobuf</groupId>
        <artifactId>protobuf-java</artifactId>
        <version>3.21.4</version>
    </dependency>
</dependencies>

3.配置canal的数据源

canal:
  server: 127.0.0.1:11111 #canal 默认端口11111
  destination: example
spring:
  application:
    name: canal-sb-demo
  datasource:
    driver-class-name: com.mysql.cj.jdbc.Driver
    url: jdbc:mysql://127.0.0.1:3306/canal-demo?useUnicode=true&characterEncoding=utf-8&serverTimezone=UTC&useSSL=false
    username: root
    password: admin

4.创建实体对象

package com.langfeiyes.sb.domain;

public class User {
    private Long id;
    private String name;
    private Integer age;

    public Long getId() {
        return id;
    }

    public void setId(Long id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public Integer getAge() {
        return age;
    }

    public void setAge(Integer age) {
        this.age = age;
    }

    @Override
    public String toString() {
        return "User{" +
                "id=" + id +
                ", name='" + name + '\'' +
                ", age=" + age +
                '}';
    }

}

5.监控处理类

package com.langfeiyes.sb.handler;

import com.langfeiyes.sb.domain.User;
import org.springframework.stereotype.Component;
import top.javatool.canal.client.annotation.CanalTable;
import top.javatool.canal.client.handler.EntryHandler;

@Component
@CanalTable(value = "user")
public class UserHandler implements EntryHandler<User> {
 
    @Override
    public void insert(User user) {
        System.err.println("添加：" + user);
    }
 
    @Override
    public void update(User before, User after) {
        System.err.println("改前：" + before);
        System.err.println("改后：" + after);

    }
    @Override
    public void delete(User user) {
        System.err.println("删除：" + user);
    }
}

6.启动类

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

7.测试

• 先启动canal服务器

• 再启动项目

• 修改user表

• 观察结果