mybatis动态数据源配置（附自定义注解实现数据源切换）

在做DB数据迁移需求的时候要用到多数据源，正好整理下

实际用到以下几个类

配置文件

#端口
server.port: 8080
spring.application.name: lzqdemo

# mysql
db.driverClassName=com.mysql.jdbc.Driver
db.url=jdbc:mysql://127.0.0.1:3306/db1?serverTimezone=GMT%2B8&useUnicode=true&characterEncoding=utf8&useSSL=false
db.username=root
db.password=123456
#数据库2
db2.driverClassName=com.mysql.jdbc.Driver
db2.url=jdbc:mysql://127.0.0.1:3306/db2?serverTimezone=GMT%2B8&useUnicode=true&characterEncoding=utf8&useSSL=false
db2.username=root
db2.password=123456

一定要加上exclude = {DataSourceAutoConfiguration.class}

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.autoconfigure.jdbc.DataSourceAutoConfiguration;

//移除默认数据库配置类
@SpringBootApplication(exclude = {DataSourceAutoConfiguration.class})
public class DbDemoApplication {

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

}

@Configuration
public class DBConfig {

	private static HLogger logger = HLoggerFactory.getLogger(DBConfig.class);
	
	@Autowired
	@Qualifier("dynamicDataSource")
	private DataSource dynamicDataSource;

	//当前主数据源
	@Bean(name = "dbOne")
	@ConfigurationProperties(prefix = "db")
	public DataSource dataSource1() {
		logger.info(">>>>>>>>>>> masterDataSource config init.");
		return DataSourceBuilder.create().build();
	}


	//需要迁移的旧DB数据源
	@Bean(name = "dbTwo")
	@ConfigurationProperties(prefix = "db2")
	public DataSource dataSource2() {
		logger.info(">>>>>>>>>>> slaveDataSource config init.");
		return DataSourceBuilder.create().build();
	}
	
	@Bean
	public MySqlSessionFactoryBean sqlSessionFactoryBean() throws Exception {
		MySqlSessionFactoryBean sqlSessionFactoryBean = new MySqlSessionFactoryBean();
		sqlSessionFactoryBean.setDaoBasePackage("自己项目的mapper包路径");
		sqlSessionFactoryBean.setDataSource(dynamicDataSource);
		sqlSessionFactoryBean.setModelBasePackage("自己项目的entity路径");
		sqlSessionFactoryBean.setDaoSuffix("Dao");
		sqlSessionFactoryBean.setModelSuffix("Entity");
		Resource[] resources = new PathMatchingResourcePatternResolver().getResources("classpath*:mybatis/mapper*.xml");
		sqlSessionFactoryBean.setMapperLocations(resources);

		//加入本地config配置，确保转出的字段如果为null可以存在map内
		Resource resources2 = new PathMatchingResourcePatternResolver().getResource("classpath:mybatis-config.xml");
		sqlSessionFactoryBean.setConfigLocation(resources2);
		return sqlSessionFactoryBean;
	}

	@Bean
	public PlatformTransactionManager transactionManager() {
		return new DataSourceTransactionManager(dynamicDataSource);
	}
}

注意这里事务一样要配置，不然切换数据源后不会生效

	  
	@Bean
	public PlatformTransactionManager transactionManager() {
		return new DataSourceTransactionManager(dynamicDataSource);
	}

@Component
//@ConfigurationProperties("spring.datasource")
public class DataSourceConfig {

    @Autowired
    @Qualifier("dbOne")
    DataSource dataSource1;

    @Autowired
    @Qualifier("dbTwo")
    DataSource dataSource2;

    
    @Primary
    @Bean(name = "dynamicDataSource")
    public DataSource dynamicDataSource() {
        DynamicDataSource dynamicDataSource = new DynamicDataSource();
        // 默认数据源
        dynamicDataSource.setDefaultTargetDataSource(dataSource1);
        // 配置多数据源
        Map dsMap = new HashMap<>();
        dsMap.put("dbOne", dataSource1);
        dsMap.put("dbTwo", dataSource2);

        dynamicDataSource.setTargetDataSources(dsMap);
        return dynamicDataSource;
    }

  
}

public class DataSourceUtil {
    
    public static final String DEFAULT_DS = "dbOne";
    
    private static final ThreadLocal contextHolder = new ThreadLocal<>();

    
    public static void setDB(String dbType) {
        contextHolder.set(dbType);
    }

    
    public static String getDB() {
        return (contextHolder.get());
    }

    
    public static void clearDB() {
        contextHolder.remove();
    }
}

import org.springframework.jdbc.datasource.lookup.AbstractRoutingDataSource;

public class DynamicDataSource extends AbstractRoutingDataSource {

    @Override
    protected Object determineCurrentLookupKey() {
        return DataSourceUtil.getDB();
    }
}

@Retention(RetentionPolicy.RUNTIME)
@Target({ElementType.METHOD,ElementType.TYPE})
public @interface TargetDataSource {
    String connName() default "dbOne";
}

import org.aspectj.lang.JoinPoint;
import org.aspectj.lang.annotation.After;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Before;
import org.aspectj.lang.reflect.MethodSignature;
import org.springframework.stereotype.Component;

import java.lang.reflect.Method;

@Aspect
@Component
public class DataSourceExchange {

    @Before("@annotation(TargetDataSource)")
    public void before(JoinPoint joinPoint){
        MethodSignature sign = (MethodSignature) joinPoint.getSignature();
        Method method = sign.getMethod();
        boolean isMethodAop= method.isAnnotationPresent(TargetDataSource.class);
        if (isMethodAop){
            TargetDataSource datasource = method.getAnnotation(TargetDataSource.class);
            DataSourceUtil.setDB(datasource.connName());
            //DataSourceHolder.setDataSources(datasource.connName());
        }else {
            if (joinPoint.getTarget().getClass().isAnnotationPresent(TargetDataSource.class)){
                TargetDataSource datasource = joinPoint.getTarget().getClass().getAnnotation(TargetDataSource.class);
                DataSourceUtil.setDB(datasource.connName());
                //DataSourceHolder.setDataSources(datasource.connName());
            }
        }
    }

    @After("@annotation(TargetDataSource)")
    public void after(){
        DataSourceUtil.clearDB();
        //DataSourceHolder.clearDataSource();
    }
}

connName传你要使用的数据源就可以了

	@TargetDataSource(connName = "dbTwo")
    public List> getListMap(String tableName, Map fieldsMap, String startTime,String endTime,int queryType){
        Map map = new HashMap<>();
        map.put("tableName", tableName);
        map.put("fieldsMap", fieldsMap);
        map.put("startTime", startTime);
        map.put("endTime", endTime);
        if (queryType==0){
            return dataMigrationDao.queryByCreateDateList(map);
        }else if (queryType==1){
            return dataMigrationDao.queryByCreateTimeList(map);
        }else if (queryType==3){
            return dataMigrationDao.queryByModifyDateList(map);
        }else if (queryType==4){
            return dataMigrationDao.queryByUpdateTimeList(map);
        }
        return new ArrayList<>();
    }