#the first datasource
jdbc.driverClassName = com.mysql.jdbc.Driver
jdbc.url = jdbc:mysql://xxx:3306/mytestdb?zeroDateTimeBehavior=convertToNull&useUnicode=true&characterEncoding=utf-8
jdbc.username = root
jdbc.password = 123

#the second datasource
jdbc2.driverClassName = com.mysql.jdbc.Driver
jdbc2.url = jdbc:mysql://xxx:3306/mytestdb2?zeroDateTimeBehavior=convertToNull&useUnicode=true&characterEncoding=utf-8
jdbc2.username = root
jdbc2.password = 123

package com.xxx.firstboot.common.datasource;

/**
 * 列出所有的數(shù)據(jù)源key（常用數(shù)據(jù)庫(kù)名稱(chēng)來(lái)命名）
 * 注意：
 * 1）這里數(shù)據(jù)源與數(shù)據(jù)庫(kù)是一對(duì)一的
 * 2）DatabaseType中的變量名稱(chēng)就是數(shù)據(jù)庫(kù)的名稱(chēng)
 */
public enum DatabaseType {
  mytestdb,mytestdb2
}

package com.xxx.firstboot.common.datasource;

/**
 * 作用：
 * 1、保存一個(gè)線程安全的DatabaseType容器
 */
public class DatabaseContextHolder {
  private static final ThreadLocal<DatabaseType> contextHolder = new ThreadLocal<>();
  
  public static void setDatabaseType(DatabaseType type){
    contextHolder.set(type);
  }
  
  public static DatabaseType getDatabaseType(){
    return contextHolder.get();
  }
}

package com.xxx.firstboot.common.datasource;

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

/**
 * 動(dòng)態(tài)數(shù)據(jù)源（需要繼承AbstractRoutingDataSource）
 */
public class DynamicDataSource extends AbstractRoutingDataSource {
  protected Object determineCurrentLookupKey() {
    return DatabaseContextHolder.getDatabaseType();
  }
}

package com.xxx.firstboot.common;

import java.util.HashMap;
import java.util.Map;
import java.util.Properties;

import javax.sql.DataSource;

import org.apache.ibatis.session.SqlSessionFactory;
import org.mybatis.spring.SqlSessionFactoryBean;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Primary;
import org.springframework.core.env.Environment;
import org.springframework.core.io.support.PathMatchingResourcePatternResolver;
import org.springframework.jdbc.datasource.DataSourceTransactionManager;

import com.alibaba.druid.pool.DruidDataSourceFactory;
import com.xxx.firstboot.common.datasource.DatabaseType;
import com.xxx.firstboot.common.datasource.DynamicDataSource;

/**
 * springboot集成mybatis的基本入口 1）創(chuàng)建數(shù)據(jù)源(如果采用的是默認(rèn)的tomcat-jdbc數(shù)據(jù)源，則不需要)
 * 2）創(chuàng)建SqlSessionFactory 3）配置事務(wù)管理器，除非需要使用事務(wù)，否則不用配置
 */
@Configuration // 該注解類(lèi)似于spring配置文件
@MapperScan(basePackages = "com.xxx.firstboot.mapper")
public class MyBatisConfig {

  @Autowired
  private Environment env;

  /**
   * 創(chuàng)建數(shù)據(jù)源(數(shù)據(jù)源的名稱(chēng)：方法名可以取為XXXDataSource(),XXX為數(shù)據(jù)庫(kù)名稱(chēng),該名稱(chēng)也就是數(shù)據(jù)源的名稱(chēng))
   */
  @Bean
  public DataSource myTestDbDataSource() throws Exception {
    Properties props = new Properties();
    props.put("driverClassName", env.getProperty("jdbc.driverClassName"));
    props.put("url", env.getProperty("jdbc.url"));
    props.put("username", env.getProperty("jdbc.username"));
    props.put("password", env.getProperty("jdbc.password"));
    return DruidDataSourceFactory.createDataSource(props);
  }

  @Bean
  public DataSource myTestDb2DataSource() throws Exception {
    Properties props = new Properties();
    props.put("driverClassName", env.getProperty("jdbc2.driverClassName"));
    props.put("url", env.getProperty("jdbc2.url"));
    props.put("username", env.getProperty("jdbc2.username"));
    props.put("password", env.getProperty("jdbc2.password"));
    return DruidDataSourceFactory.createDataSource(props);
  }

  /**
   * @Primary 該注解表示在同一個(gè)接口有多個(gè)實(shí)現(xiàn)類(lèi)可以注入的時(shí)候，默認(rèn)選擇哪一個(gè)，而不是讓@autowire注解報(bào)錯(cuò)
   * @Qualifier 根據(jù)名稱(chēng)進(jìn)行注入，通常是在具有相同的多個(gè)類(lèi)型的實(shí)例的一個(gè)注入（例如有多個(gè)DataSource類(lèi)型的實(shí)例）
   */
  @Bean
  @Primary
  public DynamicDataSource dataSource(@Qualifier("myTestDbDataSource") DataSource myTestDbDataSource,
      @Qualifier("myTestDb2DataSource") DataSource myTestDb2DataSource) {
    Map<Object, Object> targetDataSources = new HashMap<>();
    targetDataSources.put(DatabaseType.mytestdb, myTestDbDataSource);
    targetDataSources.put(DatabaseType.mytestdb2, myTestDb2DataSource);

    DynamicDataSource dataSource = new DynamicDataSource();
    dataSource.setTargetDataSources(targetDataSources);// 該方法是AbstractRoutingDataSource的方法
    dataSource.setDefaultTargetDataSource(myTestDbDataSource);// 默認(rèn)的datasource設(shè)置為myTestDbDataSource

    return dataSource;
  }

  /**
   * 根據(jù)數(shù)據(jù)源創(chuàng)建SqlSessionFactory
   */
  @Bean
  public SqlSessionFactory sqlSessionFactory(DynamicDataSource ds) throws Exception {
    SqlSessionFactoryBean fb = new SqlSessionFactoryBean();
    fb.setDataSource(ds);// 指定數(shù)據(jù)源(這個(gè)必須有，否則報(bào)錯(cuò))
    // 下邊兩句僅僅用于*.xml文件，如果整個(gè)持久層操作不需要使用到xml文件的話（只用注解就可以搞定），則不加
    fb.setTypeAliasesPackage(env.getProperty("mybatis.typeAliasesPackage"));// 指定基包
    fb.setMapperLocations(
        new PathMatchingResourcePatternResolver().getResources(env.getProperty("mybatis.mapperLocations")));//

    return fb.getObject();
  }

  /**
   * 配置事務(wù)管理器
   */
  @Bean
  public DataSourceTransactionManager transactionManager(DynamicDataSource dataSource) throws Exception {
    return new DataSourceTransactionManager(dataSource);
  }

}

package com.xxx.firstboot.mapper;

import org.apache.ibatis.annotations.Param;
import org.apache.ibatis.annotations.Result;
import org.apache.ibatis.annotations.Results;
import org.apache.ibatis.annotations.Select;

import com.xxx.firstboot.domain.Shop;

public interface ShopMapper {

  @Select("SELECT * FROM t_shop WHERE id = #{id}")
  @Results(value = { @Result(id = true, column = "id", property = "id"),
            @Result(column = "shop_name", property = "shopName") })
  public Shop getShop(@Param("id") int id);

}

package com.xxx.firstboot.dao;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Repository;

import com.xxx.firstboot.common.datasource.DatabaseContextHolder;
import com.xxx.firstboot.common.datasource.DatabaseType;
import com.xxx.firstboot.domain.Shop;
import com.xxx.firstboot.mapper.ShopMapper;

@Repository
public class ShopDao {
  @Autowired
  private ShopMapper mapper;

  /**
   * 獲取shop
   */
  public Shop getShop(int id) {
    DatabaseContextHolder.setDatabaseType(DatabaseType.mytestdb2);
    return mapper.getShop(id);
  }
}

package com.xxx.firstboot.service;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import com.xxx.firstboot.dao.ShopDao;
import com.xxx.firstboot.domain.Shop;

@Service
public class ShopService {

  @Autowired
  private ShopDao dao;

  public Shop getShop(int id) {
    return dao.getShop(id);
  }
}

package com.xxx.firstboot.web;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;

import com.xxx.firstboot.domain.Shop;
import com.xxx.firstboot.service.ShopService;

import io.swagger.annotations.Api;
import io.swagger.annotations.ApiOperation;

@RestController
@RequestMapping("/shop")
@Api("shopController相關(guān)api")
public class ShopController {

  @Autowired
  private ShopService service;

  @ApiOperation("獲取shop信息,測(cè)試多數(shù)據(jù)源")
  @RequestMapping(value = "/getShop", method = RequestMethod.GET)
  public Shop getShop(@RequestParam("id") int id) {
    return service.getShop(id);
  }

}