springboot+mybatis多数据源解决方案
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pringboot+mybatis多数据源自动切换解决方案
在项目开发中，难免会遇到需要查询多个数据源的数据。
简单点，举个例子：需要写一个查找用户订单详情的接口。此时，用户表是存储在mysql，而订单表是存储在sql-server
查询流程：1、查询用户的基本信息
2、查询该用户的订单信息
3、组装数据返回
这里就需要用到数据源自动切换了，使用mysql数据源查询出用户基本信息后，需要切换成sql-server数据
源查询该用户的订单信息。
源查询该用户的订单信息。
有两种解决方案：
// =========================== 方案一
在这里，我选择在DAO层(数据交换层)进行数据源切换。设置默认的数据源是：mysql
那么问题来了，怎么进行数据源切换呢？
Spring AOP；既然，选择了在DAO层进行切换，那切入点就是mybatis的mapper类。单独为sql-server的mapper创建一个package msmapper
调用sql-server的mapper前，切换成sql-server的数据源；查询完数据后，再切换为mysql的数据源。
没错，就这么简单，上代码。
/**
* 数据源
* @author choimeyu
* @date 2018/04/20
*/
public enum DataSourceKey {
MYSQL,
SQLSERVER
}import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* 保存当前线程使用的数据源名
* @author choimeyu
* @date 2018/04/21
*/
public class DataSourceContextHolder {
public static final Logger LOGGER = LoggerFactory.getLogger(DataSourceContextHolder.class);
private static final ThreadLocalimport org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.stereotype.Component;
/**
* dao层数据源切换切面
* @author choimeyu
* @date 2018/04/21
*/
@Aspect
@Component
public class DynamicDataSourceAspect {
private static final Logger LOGGER = LoggerFactory.getLogger(DynamicDataSourceAspect.class);
@Pointcut("execution(* com.choimeyu.tech.common.mssqlmapper.*.*(..))")
public void daoAop() {
}
@Before("daoAop()")
public void beforeSwitchDS(JoinPoint joinPoint) {
// 切换数据源
DataSourceContextHolder.setDB(DataSourceKey.SQLSERVER);
}
@After("daoAop()")
public void afterSwitchDS(JoinPoint joinPoint) {
DataSourceContextHolder.clearDB();
LOGGER.info("Restore DataSource to [{}] in Method [{}]",
DataSourceContextHolder.getDB(), joinPoint.getSignature());
}
}import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.jdbc.datasource.lookup.AbstractRoutingDataSource;
/**
* @author choimeyu
* @date 2018/04/21
*/
public class DynamicRoutingDataSource extends AbstractRoutingDataSource {
private static final Logger LOGGER = LoggerFactory.getLogger(DynamicRoutingDataSource.class);
@Override
protected Object determineCurrentLookupKey() {
LOGGER.debug("数据源为{}", DataSourceContextHolder.getDB());
return DataSourceContextHolder.getDB();
}
}* 数据源配置
* @author choimeyu
* @date 2018/04/21
*/
@Configuration
public class DataSourceConfigurer {
/**
* mysql DataSource
*
* @return dataSource
* @Primary 注解用于标识默认使用的 DataSource Bean，因为有多个 DataSource Bean，该注解可用于 dev
* 或 source DataSource Bean, 但不能用于 dynamicDataSource Bean, 否则会产生循环调用
* @ConfigurationProperties 注解用于从 application.properties 文件中读取配置，为 Bean 设置属性
*/
@Bean("mysqlDS")
@Primary
@ConfigurationProperties(prefix = "spring.datasource.mysql")
public DataSource mysqlDS() {
// 使用Druid连接池
return DruidDataSourceBuilder.create().build();
}
/**
* sqlServer DataSource
* @return
*/
@Bean("sqlServerDS")
@ConfigurationProperties(prefix = "spring.datasource.sqlserver")
public DataSource sqlServerDS() {
return DruidDataSourceBuilder.create().build();
}
/**
* dynamic DataSource
* @return
*/
@Bean("dynamicDS")
public DataSource dynamicDataSource() {
DynamicRoutingDataSource dynamicRoutingDataSource = new DynamicRoutingDataSource();
Map dataSourceMap = new HashMap<>(2);
dataSourceMap.put(DataSourceKey.MYSQL, mysqlDS());
dataSourceMap.put(DataSourceKey.SQLSERVER, sqlServerDS());
// 设置默认数据源为mysql
dynamicRoutingDataSource.setDefaultTargetDataSource(mysqlDS());
// 设置mysql和sqlServer为指定数据源
dynamicRoutingDataSource.setTargetDataSources(dataSourceMap);
return dynamicRoutingDataSource;
}
@Bean
public SqlSessionFactory sqlSessionFactory() throws Exception {
SqlSessionFactoryBean factoryBean = new SqlSessionFactoryBean();
factoryBean.setDataSource(mysqlDS());
PathMatchingResourcePatternResolver resolver = new PathMatchingResourcePatternResolver();
factoryBean.setMapperLocations(resolver.getResources("classpath:com/choimeyu/tech/common/mapper/*.xml"));
factoryBean.setTypeAliasesPackage("com.choimeyu.tech.common.model");
return factoryBean.getObject();
}
@Bean
public SqlSessionFactory sqlServerSessionFactory() throws Exception {
SqlSessionFactoryBean factoryBean = new SqlSessionFactoryBean();
factoryBean.setDataSource(sqlServerDS());
PathMatchingResourcePatternResolver resolver = new PathMatchingResourcePatternResolver();
factoryBean.setMapperLocations(resolver.getResources("classpath:com/choimeyu/tech/common/mssqlmapper/*.xml"));
factoryBean.setTypeAliasesPackage("com.choimeyu.tech.common.model");
return factoryBean.getObject();
}
} import tk.mybatis.mapper.common.Mapper;
import tk.mybatis.mapper.common.SqlServerMapper;
public interface BaseSqlServerDao extends Mapper, SqlServerMapper {
} import tk.mybatis.mapper.common.Mapper;
import tk.mybatis.mapper.common.MySqlMapper;
public interface BaseDao extends Mapper,MySqlMapper{
} import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import tk.mybatis.spring.mapper.MapperScannerConfigurer;
import java.util.Properties;
/**
* mybatis配置
* @author choimeyu
*
*/
@Configuration
public class MyBatisMapperScannerConfig {
@Bean
public MapperScannerConfigurer mapperScannerConfigurer() {
MapperScannerConfigurer mapperScannerConfigurer = new MapperScannerConfigurer();
mapperScannerConfigurer.setSqlSessionFactoryBeanName("sqlSessionFactory");
mapperScannerConfigurer.setBasePackage("com.choimeyu.tech.common.mapper");
Properties properties = new Properties();
properties.setProperty("mappers", BaseDao.class.getName());
properties.setProperty("notEmpty", "false");
properties.setProperty("IDENTITY", "MYSQL");
mapperScannerConfigurer.setProperties(properties);
return mapperScannerConfigurer;
}
@Bean
public MapperScannerConfigurer mapperScannerConfigurer1() {
MapperScannerConfigurer mapperScannerConfigurer = new MapperScannerConfigurer();
mapperScannerConfigurer.setSqlSessionFactoryBeanName("sqlServerSessionFactory");
mapperScannerConfigurer.setBasePackage("com.choimeyu.tech.common.mssqlmapper");
Properties properties = new Properties();
properties.setProperty("mappers", BaseSqlServerDao.class.getName());
properties.setProperty("notEmpty", "false");
properties.setProperty("IDENTITY", "SQLSERVER");
mapperScannerConfigurer.setProperties(properties);
return mapperScannerConfigurer;
}
}
// =========================== 方案二
第二种方案。更加简单，无需我们手写切换数据源代码，只需要配置Druid连接池即可进行切换，需要注意的是：使用了mybatis Pagehelper分页插件时，需要在spring.yml配置文件中多加个配置，才能生效。如下
spring:
省略 . . .
pagehelper:
auto-runtime-dialect: trueimport com.alibaba.druid.spring.boot.autoconfigure.DruidDataSourceBuilder;
import com.choimeyu.tech.common.constant.DataSourceKey;
import org.apache.ibatis.session.SqlSessionFactory;
import org.mybatis.spring.SqlSessionFactoryBean;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Primary;
import org.springframework.core.io.support.PathMatchingResourcePatternResolver;
import javax.sql.DataSource;
import java.util.HashMap;
import java.util.Map;
/**
* 数据源配置
* @author choimeyu
* @date 2018/04/21
*/
@Configuration
public class DataSourceConfigurer {
/**
* mysql DataSource
*
* @return dataSource
* @Primary 注解用于标识默认使用的 DataSource Bean，因为有多个 DataSource Bean，该注解可用于 dev
* 或 source DataSource Bean, 但不能用于 dynamicDataSource Bean, 否则会产生循环调用
* @ConfigurationProperties 注解用于从 application.properties 文件中读取配置，为 Bean 设置属性
*/
@Bean("mysqlDS")
@Primary
@ConfigurationProperties(prefix = "spring.datasource.mysql")
public DataSource mysqlDS() {
// 使用Druid连接池
return DruidDataSourceBuilder.create().build();
}
/**
* sqlServer DataSource
* @return
*/
@Bean("sqlServerDS")
@ConfigurationProperties(prefix = "spring.datasource.sqlserver")
public DataSource sqlServerDS() {
return DruidDataSourceBuilder.create().build();
}
/**
* dynamic DataSource
* @return
*/
@Bean("dynamicDS")
public DataSource dynamicDataSource() {
DynamicRoutingDataSource dynamicRoutingDataSource = new DynamicRoutingDataSource();
Map dataSourceMap = new HashMap<>(2);
dataSourceMap.put(DataSourceKey.MYSQL, mysqlDS());
dataSourceMap.put(DataSourceKey.SQLSERVER, sqlServerDS());
// 设置默认数据源为mysql
dynamicRoutingDataSource.setDefaultTargetDataSource(mysqlDS());
// 设置mysql和sqlServer为指定数据源
dynamicRoutingDataSource.setTargetDataSources(dataSourceMap);
return dynamicRoutingDataSource;
}
@Bean
public SqlSessionFactory sqlSessionFactory() throws Exception {
SqlSessionFactoryBean factoryBean = new SqlSessionFactoryBean();
factoryBean.setDataSource(mysqlDS());
PathMatchingResourcePatternResolver resolver = new PathMatchingResourcePatternResolver();
factoryBean.setMapperLocations(resolver.getResources("classpath:com/choimeyu/tech/common/mapper/*.xml"));
factoryBean.setTypeAliasesPackage("com.choimeyu.tech.common.model");
return factoryBean.getObject();
}
@Bean
public SqlSessionFactory sqlServerSessionFactory() throws Exception {
SqlSessionFactoryBean factoryBean = new SqlSessionFactoryBean();
factoryBean.setDataSource(sqlServerDS());
PathMatchingResourcePatternResolver resolver = new PathMatchingResourcePatternResolver();
factoryBean.setMapperLocations(resolver.getResources("classpath:com/choimeyu/tech/common/mssqlmapper/*.xml"));
factoryBean.setTypeAliasesPackage("com.choimeyu.tech.common.model");
return factoryBean.getObject();
}
} import tk.mybatis.mapper.common.Mapper;
import tk.mybatis.mapper.common.SqlServerMapper;
public interface BaseSqlServerDao extends Mapper, SqlServerMapper {
} import tk.mybatis.mapper.common.Mapper;
import tk.mybatis.mapper.common.MySqlMapper;
public interface BaseDao extends Mapper,MySqlMapper{
} import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import tk.mybatis.spring.mapper.MapperScannerConfigurer;
import java.util.Properties;
/**
* mybatis配置
* @author choimeyu
*
*/
@Configuration
public class MyBatisMapperScannerConfig {
@Bean
public MapperScannerConfigurer mapperScannerConfigurer() {
MapperScannerConfigurer mapperScannerConfigurer = new MapperScannerConfigurer();
mapperScannerConfigurer.setSqlSessionFactoryBeanName("sqlSessionFactory");
mapperScannerConfigurer.setBasePackage("com.choimeyu.tech.common.mapper");
Properties properties = new Properties();
properties.setProperty("mappers", BaseDao.class.getName());
properties.setProperty("notEmpty", "false");
properties.setProperty("IDENTITY", "MYSQL");
mapperScannerConfigurer.setProperties(properties);
return mapperScannerConfigurer;
}
@Bean
public MapperScannerConfigurer mapperScannerConfigurer1() {
MapperScannerConfigurer mapperScannerConfigurer = new MapperScannerConfigurer();
mapperScannerConfigurer.setSqlSessionFactoryBeanName("sqlServerSessionFactory");
mapperScannerConfigurer.setBasePackage("com.choimeyu.tech.common.mssqlmapper");
Properties properties = new Properties();
properties.setProperty("mappers", BaseSqlServerDao.class.getName());
properties.setProperty("notEmpty", "false");
properties.setProperty("IDENTITY", "SQLSERVER");
mapperScannerConfigurer.setProperties(properties);
return mapperScannerConfigurer;
}
}