@Component
@Primary
public class DynamicDataSource extends AbstractRoutingDataSource {
    // 當前使用的數(shù)據(jù)源標識
    public static ThreadLocal<String> name=new ThreadLocal<>();
    // 寫數(shù)據(jù)源
    @Autowired
    DataSource dataSource1;
    // 讀數(shù)據(jù)源
    @Autowired
    DataSource dataSource2;

    @Override
    protected Object determineCurrentLookupKey() {
        return name.get();
    }
    @Override
    public void afterPropertiesSet() {
        // 為targetDataSources初始化所有數(shù)據(jù)源
        Map<Object, Object> targetDataSources=new HashMap<>();
        targetDataSources.put("W",dataSource1);
        targetDataSources.put("R",dataSource2);

        super.setTargetDataSources(targetDataSources);

        // 為defaultTargetDataSource 設置默認的數(shù)據(jù)源
        super.setDefaultTargetDataSource(dataSource1);

        super.afterPropertiesSet();

    }

}

@Configuration
public class DataSourceConfig {
	/**
		數(shù)據(jù)庫1的配置
	/
    @Bean
    @ConfigurationProperties(prefix = "spring.datasource.datasource1")
    public DataSource dataSource1() {
        // 底層會自動拿到spring.datasource中的配置， 創(chuàng)建一個DruidDataSource
        return DruidDataSourceBuilder.create().build();
    }

	/**
		數(shù)據(jù)庫2的配置
	/
    @Bean
    @ConfigurationProperties(prefix = "spring.datasource.datasource2")
    public DataSource dataSource2() {
        // 底層會自動拿到spring.datasource中的配置， 創(chuàng)建一個DruidDataSource
        return DruidDataSourceBuilder.create().build();
    }
    @Bean
    public DataSourceTransactionManager transactionManager1(DynamicDataSource dataSource){
        DataSourceTransactionManager dataSourceTransactionManager = new DataSourceTransactionManager();
        dataSourceTransactionManager.setDataSource(dataSource);
        return dataSourceTransactionManager;
    }

    @Bean
    public DataSourceTransactionManager transactionManager2(DynamicDataSource dataSource){
        DataSourceTransactionManager dataSourceTransactionManager = new DataSourceTransactionManager();
        dataSourceTransactionManager.setDataSource(dataSource);
        return dataSourceTransactionManager;
    }
}

@Target({ElementType.METHOD,ElementType.TYPE})
@Retention(RetentionPolicy.RUNTIME)
public @interface WR {
    String value() default "W";
}

@Component
@Aspect
public class DynamicDataSourceAspect implements Ordered {
    // 前置
    @Before("within(org.arkham.dynamic_datasource.service.impl.*) && @annotation(wr)")
    public void before(JoinPoint point, WR wr){
        String name = wr.value();
        DynamicDataSource.name.set(name);
    }
    @Override
    public int getOrder() {
        return 0;
    }
}

@Service
public class UserImplService implements UserService {

    @Autowired
    UserMapper userMapper;


    @Override
    @WR("R")        // 庫1
    public List<User> list() {
        return userMapper.list();
    }

    @Override
    @WR("W")        // 庫2
    public void save(User friend) {
        userMapper.save(friend);
    }
}

@Configuration
// 繼承mybatis:
// 1. 指定掃描的mapper接口包（主庫）
// 2. 指定使用sqlSessionFactory是哪個（主庫）
@MapperScan(basePackages = "org.arkham.dynamic_datasource_mybatis.mapper.w",
        sqlSessionFactoryRef="wSqlSessionFactory")
public class WMyBatisConfig {
    @Bean
    @ConfigurationProperties(prefix = "spring.datasource.datasource1")
    public DataSource dataSource1() {
        // 底層會自動拿到spring.datasource中的配置， 創(chuàng)建一個DruidDataSource
        return DruidDataSourceBuilder.create().build();
    }

    @Bean
    @Primary
    public SqlSessionFactory wSqlSessionFactory()
            throws Exception {
        final SqlSessionFactoryBean sessionFactory = new SqlSessionFactoryBean();
        // 指定主庫
        sessionFactory.setDataSource(dataSource1());
        // 可以手動指定主庫對應的mapper.xml文件
        /*sessionFactory.setMapperLocations(new PathMatchingResourcePatternResolver()
                .getResources("classpath:mapper/order/*.xml"));*/
        return sessionFactory.getObject();
    }

    @Bean
    @Primary
    public DataSourceTransactionManager wTransactionManager(){
        DataSourceTransactionManager dataSourceTransactionManager = new DataSourceTransactionManager();
        dataSourceTransactionManager.setDataSource(dataSource1());
        return dataSourceTransactionManager;
    }


    @Bean
    public TransactionTemplate wTransactionTemplate(){
        return new TransactionTemplate(wTransactionManager());
    }
}

@Configuration
// 繼承mybatis:
// 1. 指定掃描的mapper接口包（主庫）
// 2. 指定使用sqlSessionFactory是哪個（主庫）
@MapperScan(basePackages = "org.arkham.dynamic_datasource_mybatis.mapper.r",
        sqlSessionFactoryRef="rSqlSessionFactory")
public class RMyBatisConfig {
    @Bean
    @ConfigurationProperties(prefix = "spring.datasource.datasource2")
    public DataSource dataSource2() {
        // 底層會自動拿到spring.datasource中的配置， 創(chuàng)建一個DruidDataSource
        return DruidDataSourceBuilder.create().build();
    }

    @Bean
    @Primary
    public SqlSessionFactory rSqlSessionFactory()
            throws Exception {
        final SqlSessionFactoryBean sessionFactory = new SqlSessionFactoryBean();
        // 指定主庫
        sessionFactory.setDataSource(dataSource2());
        // 可以手動指定主庫對應的mapper.xml文件
        /*sessionFactory.setMapperLocations(new PathMatchingResourcePatternResolver()
                .getResources("classpath:mapper/r/*.xml"));*/
        return sessionFactory.getObject();
    }



    @Bean
    public DataSourceTransactionManager rTransactionManager(){
        DataSourceTransactionManager dataSourceTransactionManager = new DataSourceTransactionManager();
        dataSourceTransactionManager.setDataSource(dataSource2());
        return dataSourceTransactionManager;
    }

    @Bean
    public TransactionTemplate rTransactionTemplate(){
        return new TransactionTemplate(rTransactionManager());
    }

@Service
public class UserImplService implements UserService {

    @Autowired
    private RUserMapper rFriendMapper;

    @Autowired
    private WUserMapper wFriendMapper;
    // 讀-- 讀庫
    @Override
    public List<User> list() {
        return rFriendMapper.list();
    }

    // 保存-- 寫庫
    @Override
    public void save(User user) {
        wFriendMapper.save(user);
    }


    // 保存-- 寫庫
    @Override
    public void saveW(User user) {
        user.setName("xman11");
        wFriendMapper.save(user);
    }

    // 保存-- 讀庫
    @Override
    public void saveR(User user) {
        user.setName("xman");
        rFriendMapper.save(user);
    }
}

<dependency>
    <groupId>com.baomidou</groupId>
    <artifactId>dynamic-datasource-spring-boot-starter</artifactId>
    <version>3.5.0</version> <!-- 請根據(jù)項目需要調整版本 -->
</dependency>

spring:
  datasource:
    dynamic:
      primary: master # 默認數(shù)據(jù)源或數(shù)據(jù)源組，當未指定數(shù)據(jù)源時會使用該數(shù)據(jù)源
      strict: false # 設置為true表示檢查配置文件中數(shù)據(jù)源是否有效
      datasource:
        master: # 數(shù)據(jù)源一
          driver-class-name: com.mysql.cj.jdbc.Driver
          url: jdbc:mysql://localhost:3306/master_db
          username: master_user
          password: master_pass
        slave: # 數(shù)據(jù)源二
          driver-class-name: com.mysql.cj.jdbc.Driver
          url: jdbc:mysql://localhost:3306/slave_db
          username: slave_user
          password: slave_pass

@Service
public class UserImplService implements UserService {

    @Autowired
    UserMapper userMapper;

    @Override
    @DS("master")
    public void save(User user) {
        userMapper.save(user);
    }
    @Override
    @DS("slave_1")  // 從庫， 如果按照下劃線命名方式配置多個 , 可以指定前綴即可（組名）
    public List<User> list() {
        return userMapper.list();
    }
}

import com.baomidou.dynamic.datasource.annotation.DS;
import org.apache.ibatis.annotations.Mapper;
import org.apache.ibatis.annotations.Select;

@Mapper
public interface UserMapper {

    @DS("master")
    @Select("SELECT * FROM user WHERE id = #{id}")
    User getUserFromMaster(int id);

    @DS("slave")
    @Select("SELECT * FROM user WHERE id = #{id}")
    User getUserFromSlave(int id);
}