SpringBoot采用Dynamic-Datasource方式实现多JDBC数据源
作者：Bulut0907
1.1 特性
- 提供本地多数据源事务方案。由AOP实现
- 支持数据源分组，适用于多种场景，如多库读写分离、一主多从(实现了数据库负载均衡算法)、混合模式
- 提供自定义数据源来源方案(如全从数据库加载)
- 提供项目启动后动态增加移除数据源方案
- 支持数据库敏感配置信息加密(可自定义)ENC()
- 支持每个数据库独立初始化表结构schema和数据库database
- 支持无数据源启动，支持懒加载数据源(需要的时候再创建连接)
- 支持自定义注解，需继承DS(3.2.0+)
- 提供并简化对Druid、HikariCp、BeeCp、Dbcp2的快速集成
- 提供对Mybatis-Plus、Quartz、ShardingJdbc、P6sy、Jndi等组件的集成方案
- 提供Mybatis环境下的纯读写分离方案
- 提供使用spel动态参数解析数据源方案。内置spel、session、header，支持自定义
- 支持多层数据源嵌套切换。(ServiceA >>> ServiceB >>> ServiceC)
- 支持Seata分布式事务
1.2 Mysql数据准备
分别创建read_db.user和write_db.user，并向read_db.user写入数据
mysql> create database read_db;
Query OK, 1 row affected (0.14 sec)
mysql> create database write_db;
Query OK, 1 row affected (0.01 sec)
mysql> create table read_db.user (
-> id bigint(20) auto_increment not null comment '主键ID',
-> name varchar(30) null default null comment '姓名',
-> primary key (id)
-> );
Query OK, 0 rows affected, 1 warning (0.29 sec)
mysql>
mysql> insert into read_db.user (id, name) values
-> (1, 'read_name1'),
-> (2, 'read_name2'),
-> (3, 'read_name3'),
-> (4, 'read_name4'),
-> (5, 'read_name5');
Query OK, 5 rows affected (0.16 sec)
Records: 5 Duplicates: 0 Warnings: 0
mysql>
mysql> create table write_db.user (
-> id bigint(20) auto_increment not null comment '主键ID',
-> name varchar(30) null default null comment '姓名',
-> primary key (id)
-> );
Query OK, 0 rows affected, 1 warning (0.04 sec)
mysql> 2.2 通过Dynamic-Datasource实现多JDBC数据源
2.2.1 pom.xml依赖
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>8.0.31</version>
</dependency>
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>druid</artifactId>
<version>1.2.15</version>
</dependency>
<dependency>
<groupId>com.baomidou</groupId>
<artifactId>dynamic-datasource-spring-boot-starter</artifactId>
<version>3.5.2</version>
</dependency>可以看到自动添加了spring-boot-starter-jdbc、spring-boot-starter-aop依赖
2.2.2 application.properties配置
通过dynamic方式，指定了datasource1和datasource2两个DataSource
spring.datasource.type=com.alibaba.druid.pool.DruidDataSource # 设置默认的数据源。默认是master spring.datasource.dynamic.primary=datasource1 # 严格匹配数据源, 默认false。true表示未匹配到指定数据源时抛异常, false表示使用默认数据源 spring.datasource.dynamic.strict=true # 用于读的数据库 spring.datasource.dynamic.datasource.datasource1.url=jdbc:mysql://192.168.28.12:3306/read_db spring.datasource.dynamic.datasource.datasource1.username=root spring.datasource.dynamic.datasource.datasource1.password=Root_123 spring.datasource.dynamic.datasource.datasource1.driver-class-name=com.mysql.cj.jdbc.Driver # 用于写的数据库 spring.datasource.dynamic.datasource.datasource2.url=jdbc:mysql://192.168.28.12:3306/write_db spring.datasource.dynamic.datasource.datasource2.username=root spring.datasource.dynamic.datasource.datasource2.password=Root_123 spring.datasource.dynamic.datasource.datasource2.driver-class-name=com.mysql.cj.jdbc.Driver
2.2.3 使用@DS注解选择DataSource
可以在Service的类或方法上(优先级更高)使用@DS注解选择DataSource
2.2.4 使用@Transactional + @DSTransactional实现事务
可以在Service的类或方法上(优先级更高)使用@Transactional实现事务。对异常的捕获后，通过 TransactionAspectSupport.currentTransactionStatus().setRollbackOnly() 进行手动回滚
@Transactional注解会让@DS的多数据源切换失效，虽然可以通过 @Transactional(propagation = Propagation.REQUIRES_NEW) 开启一个内部子事务来使@DS切换数据源，但是大部分场景不适用
@DSTransactional能和@DS多数据源切换配合使用，@DSTransactional注解最好使用在方法上(类似好像不生效)，@DSTransactional注解不能对异常进行捕获手动回滚，只能自动回滚然后抛出异常
2.3 动态数据源测试
2.3.1 创建User类
package com.hh.springboottest.myController;
import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;
import lombok.ToString;
@NoArgsConstructor
@AllArgsConstructor
@Data
@ToString
public class User {
private Long id;
private String name;
}2.3.2 Mapper接口实现
package com.hh.springboottest.mapper;
import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import com.hh.springboottest.myController.User;
import org.apache.ibatis.annotations.Mapper;
@Mapper
public interface UserMapper extends BaseMapper<User> {
}2.3.3 Service实现
Service接口实现
package com.hh.springboottest.service;
import com.hh.springboottest.myController.User;
public interface UserService {
public User getUser(Long id);
public void saveMultiUser();
}ServiceImpl实现类。说明如下：
- @DS(“datasource1”)注解，让userMapper.selectById使用了datasource1数据源
- @DS(“datasource2”)注解，让userMapper.insert使用了datasource2数据源
- @Transactional注解，当userMapper.insert(user1)执行成功，userMapper.insert(user2)执行失败，会回滚userMapper.insert(user1)的操作
package com.hh.springboottest.service.impl;
import com.baomidou.dynamic.datasource.annotation.DS;
import com.hh.springboottest.mapper.UserMapper;
import com.hh.springboottest.myController.User;
import com.hh.springboottest.service.UserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;
@Service
public class UserServiceImpl implements UserService {
@Autowired
UserMapper userMapper;
@DS("datasource1")
@Override
public User getUser(Long id) {
return userMapper.selectById(id);
}
@Transactional
@DS("datasource2")
@Override
public void saveMultiUser() {
User user2 = new User(2L, "write_name2");
userMapper.insert(user2);
User user3 = new User(3L, "write_name3");
userMapper.insert(user3);
}
}2.3.4 测试
package com.hh.springboottest;
import com.hh.springboottest.myController.User;
import com.hh.springboottest.service.UserService;
import lombok.extern.slf4j.Slf4j;
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
@Slf4j
@SpringBootTest
public class MyApplicationTest {
@Autowired
UserService userService;
@Test
public void dynamicDataSourceTest() {
User user = userService.getUser(1L);
log.info("获取到的用户为：{}", user);
userService.saveMultiUser();
}
}运行程序，结果如下：
2022-11-24 09:16:15.733 INFO 33760 --- [ main] com.hh.springboottest.MyApplicationTest : 获取到的用户为：User(id=1, name=read_name1)
2022-11-24 09:16:15.857 INFO 33760 --- [ionShutdownHook] c.b.d.d.DynamicRoutingDataSource : dynamic-datasource start closing ....
2022-11-24 09:16:15.861 INFO 33760 --- [ionShutdownHook] com.alibaba.druid.pool.DruidDataSource : {dataSource-1} closing ...
2022-11-24 09:16:15.866 INFO 33760 --- [ionShutdownHook] com.alibaba.druid.pool.DruidDataSource : {dataSource-1} closed
2022-11-24 09:16:15.866 INFO 33760 --- [ionShutdownHook] com.alibaba.druid.pool.DruidDataSource : {dataSource-2} closing ...
2022-11-24 09:16:15.867 INFO 33760 --- [ionShutdownHook] com.alibaba.druid.pool.DruidDataSource : {dataSource-2} closed
2022-11-24 09:16:15.867 INFO 33760 --- [ionShutdownHook] c.b.d.d.DynamicRoutingDataSource : dynamic-datasource all closed success,bye
同时查看write_db.user表，数据如下：
mysql> select * from write_db.user; +----+--------------+ | id | name | +----+--------------+ | 1 | write_name1 | | 2 | write_name2 | | 3 | write_name3 | +----+--------------+ 3 rows in set (0.11 sec) mysql>
2.4 removeDataSource删除DataSource
通过DynamicRoutingDataSource的removeDataSource方法删除DataSource
package com.hh.springboottest.service.impl;
import com.baomidou.dynamic.datasource.DynamicRoutingDataSource;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import javax.sql.DataSource;
@Service
public class DataSourceServiceImpl implements DataSourceService {
@Autowired
DataSource dataSource;
public void removeDataSource(String dataSourceName) {
DynamicRoutingDataSource dynamicRoutingDataSource =
(DynamicRoutingDataSource) dataSource;
dynamicRoutingDataSource.removeDataSource(dataSourceName);
}
}到此这篇关于SpringBoot采用Dynamic-Datasource方式实现多JDBC数据源的文章就介绍到这了,更多相关SpringBoot Dynamic-Datasource JDBC数据源内容请搜索脚本之家以前的文章或继续浏览下面的相关文章希望大家以后多多支持脚本之家！