springboot+分包，实现多数据源切换和事务管理（靠谱版）

逃离我推掉我的手 2022-03-08 17:06 107阅读 0赞

**说明：之前写的这篇[springboot+aop+自定义注解，实现多数据源切换（通用版）][springboot_aop]经过测试有些发现事务无法管理，有时候切换数据源容易失败，现在用一种更靠谱的方式来实现多数据源切换。**

**一.引入相应的maven依赖**

<dependency>
    	<groupId>org.springframework.boot</groupId>
    	<artifactId>spring-boot-starter-web</artifactId>
    </dependency>
    <dependency>
    	<groupId>org.projectlombok</groupId>
    	<artifactId>lombok</artifactId>
    	<optional>true</optional>
    </dependency>
    <dependency>
    	<groupId>mysql</groupId>
    	<artifactId>mysql-connector-java</artifactId>
    </dependency>
    <dependency>
    	<groupId>com.alibaba</groupId>
    	<artifactId>druid</artifactId>
    	<version>1.0.5</version>
    </dependency>

**二.配置数据源**

*  这里application.properties配置了三个数据源

spring.datasource.user.url = jdbc:mysql://10.237.150.79:3306/user?useUnicode=true&characterEncoding=utf-8&serverTimezone=UTC&useSSL=false
    spring.datasource.user.username = root
    spring.datasource.user.password = root
    spring.datasource.user.driver-class-name = com.mysql.jdbc.Driver
    spring.datasource.user.type = com.alibaba.druid.pool.DruidDataSource
    spring.datasource.user.filters = stat
    spring.datasource.user.maxActive = 100
    spring.datasource.user.initialSize = 10
    spring.datasource.user.maxWait = 60000
    spring.datasource.user.minIdle = 500
    
    spring.datasource.china.url = jdbc:mysql://10.237.150.79:3306/china?useUnicode=true&characterEncoding=utf-8&serverTimezone=UTC&useSSL=false
    spring.datasource.china.username = root
    spring.datasource.china.password = root
    spring.datasource.china.driver-class-name = com.mysql.jdbc.Driver
    spring.datasource.china.type = com.alibaba.druid.pool.DruidDataSource
    spring.datasource.china.filters = stat
    spring.datasource.china.maxActive = 100
    spring.datasource.china.initialSize = 10
    spring.datasource.china.maxWait = 60000
    spring.datasource.china.minIdle = 500
    
    spring.datasource.world.url = jdbc:mysql://10.237.150.79:3306/world?useUnicode=true&characterEncoding=utf-8&serverTimezone=UTC&useSSL=false
    spring.datasource.world.username = root
    spring.datasource.world.password = root
    spring.datasource.world.driver-class-name = com.mysql.jdbc.Driver
    spring.datasource.world.type = com.alibaba.druid.pool.DruidDataSource
    spring.datasource.world.filters = stat
    spring.datasource.world.maxActive = 100
    spring.datasource.world.initialSize = 10
    spring.datasource.world.maxWait = 60000
    spring.datasource.world.minIdle = 500

*  分包配置数据源

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*  注入第一个数据源

/**
     * @Author: guandezhi
     * @Date: 2019/3/14 21:06
     */
    @Configuration
    @MapperScan(basePackages = {"com.gdz.dynamic.mapper.china"}, sqlSessionTemplateRef  = "chinaSqlSessionTemplate")
    public class ChinaDataSourceConfig {
    
        @Bean(name = "chinaDataSource")
        @Primary
        @ConfigurationProperties(prefix = "spring.datasource.china")
        public DataSource chinaDataSource() {
            return DataSourceBuilder.create().build();
        }
    
        @Bean(name = "chinaSqlSessionFactory")
        @Primary
        public SqlSessionFactory chinaSqlSessionFactory(@Qualifier("chinaDataSource") DataSource dataSource) throws Exception {
            SqlSessionFactoryBean bean = new SqlSessionFactoryBean();
            bean.setDataSource(dataSource);
            bean.setMapperLocations(new PathMatchingResourcePatternResolver().getResources("classpath:mapper/china/*.xml"));
            return bean.getObject();
        }
    
        @Bean(name = "chinaTransactionManager")
        @Primary
        public DataSourceTransactionManager chinaTransactionManager(@Qualifier("chinaDataSource") DataSource dataSource) {
            return new DataSourceTransactionManager(dataSource);
        }
    
        @Bean(name = "chinaSqlSessionTemplate")
        @Primary
        public SqlSessionTemplate chinaSqlSessionTemplate(@Qualifier("chinaSqlSessionFactory") SqlSessionFactory sqlSessionFactory) throws Exception {
            return new SqlSessionTemplate(sqlSessionFactory);
        }

*  注入第二个数据源

/**
     * @Author: guandezhi
     * @Date: 2019/3/14 21:06
     */
    @Configuration
    @MapperScan(basePackages = {"com.gdz.dynamic.mapper.user"}, sqlSessionTemplateRef = "userSqlSessionTemplate")
    public class UserDataSourceConfig {
    
        @Bean(name = "userDataSource")
        @ConfigurationProperties(prefix = "spring.datasource.user")
        public DataSource userDataSource() {
            return DataSourceBuilder.create().build();
        }
    
        @Bean(name = "userSqlSessionFactory")
        public SqlSessionFactory userSqlSessionFactory(@Qualifier("userDataSource") DataSource dataSource) throws Exception {
            SqlSessionFactoryBean bean = new SqlSessionFactoryBean();
            bean.setDataSource(dataSource);
            bean.setMapperLocations(new PathMatchingResourcePatternResolver().getResources("classpath:mapper/user/*.xml"));
            return bean.getObject();
        }
    
        @Bean(name = "userTransactionManager")
        public DataSourceTransactionManager userTransactionManager(@Qualifier("userDataSource") DataSource dataSource) {
            return new DataSourceTransactionManager(dataSource);
        }
    
        @Bean(name = "userSqlSessionTemplate")
        public SqlSessionTemplate userSqlSessionTemplate(@Qualifier("userSqlSessionFactory") SqlSessionFactory sqlSessionFactory) throws Exception {
            return new SqlSessionTemplate(sqlSessionFactory);
        }

*  注入第三个数据源

/**
     * @Author: guandezhi
     * @Date: 2019/3/14 21:06
     */
    @Configuration
    @MapperScan(basePackages = {"com.gdz.dynamic.mapper.world"}, sqlSessionTemplateRef  = "worldSqlSessionTemplate")
    public class WorldDataSourceConfig {
    
        @Bean(name = "worldDataSource")
        @ConfigurationProperties(prefix = "spring.datasource.world")
        public DataSource worldDataSource() {
            return DataSourceBuilder.create().build();
        }
    
        @Bean(name = "worldSqlSessionFactory")
        public SqlSessionFactory worldSqlSessionFactory(@Qualifier("worldDataSource") DataSource dataSource) throws Exception {
            SqlSessionFactoryBean bean = new SqlSessionFactoryBean();
            bean.setDataSource(dataSource);
            bean.setMapperLocations(new PathMatchingResourcePatternResolver().getResources("classpath:mapper/world/*.xml"));
            return bean.getObject();
        }
    
        @Bean(name = "worldTransactionManager")
        public DataSourceTransactionManager worldTransactionManager(@Qualifier("worldDataSource") DataSource dataSource) {
            return new DataSourceTransactionManager(dataSource);
        }
    
        @Bean(name = "worldSqlSessionTemplate")
        public SqlSessionTemplate worldSqlSessionTemplate(@Qualifier("worldSqlSessionFactory") SqlSessionFactory sqlSessionFactory) throws Exception {
            return new SqlSessionTemplate(sqlSessionFactory);
        }

这样就已经可以实现多数据源的切换了。

**总结：**

**         1.事务的使用必须要指明是哪个数据源的事务管理器，否则事务失效**

**            例如：@Transactional(value = "userTransactionManager")**

**         2.如果一个方法涉及多个数据源操作，此时无法做到同时回滚，尽量避免这种操作，**

**           这里涉及到分布式事务处理，可自行研究。**

代码地址：[https://github.com/dezhiguan/DynamicDataSource2/tree/master][https_github.com_dezhiguan_DynamicDataSource2_tree_master]

[springboot_aop]: https://blog.csdn.net/qq_35859844/article/details/88087292
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM1ODU5ODQ0_size_16_color_FFFFFF_t_70]: /images/20220308/f7f0711935de472092ef0f43c7f603e3.png
[https_github.com_dezhiguan_DynamicDataSource2_tree_master]: https://github.com/dezhiguan/DynamicDataSource2/tree/master