spring boot:使mybatis访问多个druid数据源(spring boot 2.3.2)

一，为什么要使用多个数据源?

1，什么情况下需要使用多个数据源?

当我们需要访问不同的数据库时，则需要配置配置多个数据源，

例如：电商的业务数据库(包括用户/商品/订单等)

           和统计数据库(按月日年的订单数量/金额等的统计)通常是分开到不同的数据库

所以我们需要在应用中创建多个数据库连接池

 

2,通常的作法：

     例如我们有两个数据库orderdb,goodsdb

    两个数据库的mapper.xml文件需要放到不同的目录下，

    通过给不同的目录配置不同的数据源，

    从而实现处理不同的业务功能

 

说明：刘宏缔的架构森林是一个专注架构的博客，地址：https://www.cnblogs.com/architectforest

对应的源码可以访问这里获取： https://github.com/liuhongdi/

说明：作者:刘宏缔 邮箱: 371125307@qq.com

二，演示项目的相关信息

1,项目地址:

https://github.com/liuhongdi/multidruid

2,项目功能说明：

访问两个数据库，分别打印出两个库中商品和订单的信息

3,项目结构：如图:

三，配置文件说明:

1,pom.xml

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
            <exclusions>
                <exclusion>
                    <groupId>org.springframework.boot</groupId>
                    <artifactId>spring-boot-starter-logging</artifactId>
                </exclusion>
            </exclusions>
        </dependency>

        <!--druid begin-->
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid-spring-boot-starter</artifactId>
            <version>1.1.23</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-log4j2</artifactId>
        </dependency>
        <dependency>
            <groupId>com.lmax</groupId>
            <artifactId>disruptor</artifactId>
            <version>3.4.2</version>
        </dependency>
        <!--druid   end-->

        <!--mybatis begin-->
        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>2.1.3</version>
        </dependency>
        <!--mybatis end-->

        <!--mysql begin-->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <scope>runtime</scope>
        </dependency>
        <!--mysql end-->

说明：因为给druid使用了log4j2日志，为避免冲突，

在spring-boot-starter-web中排除了spring-boot-starter-logging

2，application.properties:

#error
server.error.include-stacktrace=always
#error
logging.level.org.springframework.web=trace

#   数据源goodsdb基本配置
spring.datasource.druid.goodsdb.username = root
spring.datasource.druid.goodsdb.password = lhddemo
spring.datasource.druid.goodsdb.driver-class-name = com.mysql.cj.jdbc.Driver
spring.datasource.druid.goodsdb.url = jdbc:mysql://127.0.0.1:3306/store?serverTimezone=UTC
spring.datasource.druid.goodsdb.type = com.alibaba.druid.pool.DruidDataSource
spring.datasource.druid.goodsdb.initialSize = 5
spring.datasource.druid.goodsdb.minIdle = 5
spring.datasource.druid.goodsdb.maxActive = 20
spring.datasource.druid.goodsdb.maxWait = 60000
spring.datasource.druid.goodsdb.timeBetweenEvictionRunsMillis = 60000
spring.datasource.druid.goodsdb.minEvictableIdleTimeMillis = 300000
spring.datasource.druid.goodsdb.validationQuery = SELECT 1 FROM DUAL
spring.datasource.druid.goodsdb.testWhileIdle = true
spring.datasource.druid.goodsdb.testOnBorrow = false
spring.datasource.druid.goodsdb.testOnReturn = false
spring.datasource.druid.goodsdb.poolPreparedStatements = true
#   数据源orderdb基本配置
spring.datasource.druid.orderdb.username = root
spring.datasource.druid.orderdb.password = lhddemo
spring.datasource.druid.orderdb.driver-class-name = com.mysql.cj.jdbc.Driver
spring.datasource.druid.orderdb.url = jdbc:mysql://127.0.0.1:3306/orderdb?serverTimezone=UTC
spring.datasource.druid.orderdb.type = com.alibaba.druid.pool.DruidDataSource
spring.datasource.druid.orderdb.initialSize = 5
spring.datasource.druid.orderdb.minIdle = 5
spring.datasource.druid.orderdb.maxActive = 20
spring.datasource.druid.orderdb.maxWait = 60000
spring.datasource.druid.orderdb.timeBetweenEvictionRunsMillis = 60000
spring.datasource.druid.orderdb.minEvictableIdleTimeMillis = 300000
spring.datasource.druid.orderdb.validationQuery = SELECT 1 FROM DUAL
spring.datasource.druid.orderdb.testWhileIdle = true
spring.datasource.druid.orderdb.testOnBorrow = false
spring.datasource.druid.orderdb.testOnReturn = false
spring.datasource.druid.orderdb.poolPreparedStatements = true

#   配置监控统计拦截的filters，去掉后监控界面sql无法统计，'wall'用于防火墙
spring.datasource.druid.filters = stat,wall,log4j2
spring.datasource.druid.maxPoolPreparedStatementPerConnectionSize = 20
spring.datasource.druid.useGlobalDataSourceStat = true
spring.datasource.druid.connectionProperties = druid.stat.mergeSql=true;druid.stat.slowSqlMillis=500

#druid sql firewall monitor
spring.datasource.druid.filter.wall.enabled=true

#druid sql monitor
spring.datasource.druid.filter.stat.enabled=true
spring.datasource.druid.filter.stat.log-slow-sql=true
spring.datasource.druid.filter.stat.slow-sql-millis=10000
spring.datasource.druid.filter.stat.merge-sql=true

#druid uri monitor
spring.datasource.druid.web-stat-filter.enabled=true
spring.datasource.druid.web-stat-filter.url-pattern=/*
spring.datasource.druid.web-stat-filter.exclusions=*.js,*.gif,*.jpg,*.bmp,*.png,*.css,*.ico,/druid/*

#druid session monitor
spring.datasource.druid.web-stat-filter.session-stat-enable=true
spring.datasource.druid.web-stat-filter.profile-enable=true

#druid spring monitor
spring.datasource.druid.aop-patterns=com.druid.*

#monintor,druid login user config
spring.datasource.druid.stat-view-servlet.enabled=true
spring.datasource.druid.stat-view-servlet.login-username=root
spring.datasource.druid.stat-view-servlet.login-password=root

#mybatis
mybatis.mapper-locations=classpath:/mapper/*Mapper.xml
mybatis.type-aliases-package=com.example.demo.mapper
mybatis.configuration.log-impl=org.apache.ibatis.logging.stdout.StdOutImpl
#log
logging.config = classpath:log4j2.xml

3,log4j2.xml

<?xml version="1.0" encoding="UTF-8"?>
<configuration status="OFF">
<appenders>
    <Console name="Console" target="SYSTEM_OUT">
        <!--只接受程序中DEBUG级别的日志进行处理-->
        <ThresholdFilter level="DEBUG" onMatch="ACCEPT" onMismatch="DENY"/>
        <PatternLayout pattern="%d{yyyy-MM-dd HH:mm:ss.SSS} [%thread] [%file:%line] %-5level %logger{35} - %msg %n"/>
    </Console>
    <!--处理INFO级别的日志，并把该日志放到logs/info.log文件中-->
    <RollingFile name="RollingFileInfo" fileName="./logs/info.log"
                 filePattern="logs/$${date:yyyy-MM}/info-%d{yyyy-MM-dd}-%i.log.gz">
        <Filters>
            <ThresholdFilter level="INFO"/>
            <ThresholdFilter level="WARN" onMatch="DENY" onMismatch="NEUTRAL"/>
        </Filters>
        <PatternLayout pattern="%d{yyyy-MM-dd HH:mm:ss.SSS} [%thread] [%file:%line] %-5level %logger{35} - %msg %n"/>
        <Policies>
            <SizeBasedTriggeringPolicy size="500 MB"/>
            <TimeBasedTriggeringPolicy/>
        </Policies>
    </RollingFile>
    <!--处理WARN级别的日志，并把该日志放到logs/warn.log文件中-->
    <RollingFile name="RollingFileWarn" fileName="./logs/warn.log"
                 filePattern="logs/$${date:yyyy-MM}/warn-%d{yyyy-MM-dd}-%i.log.gz">
        <Filters>
            <ThresholdFilter level="WARN"/>
            <ThresholdFilter level="ERROR" onMatch="DENY" onMismatch="NEUTRAL"/>
        </Filters>
        <PatternLayout pattern="%d{yyyy-MM-dd HH:mm:ss.SSS} [%thread] [%file:%line] %-5level %logger{35} - %msg %n"/>
        <Policies>
            <SizeBasedTriggeringPolicy size="500 MB"/>
            <TimeBasedTriggeringPolicy/>
        </Policies>
    </RollingFile>
    <!--处理error级别的日志，并把该日志放到logs/error.log文件中-->
    <RollingFile name="RollingFileError" fileName="./logs/error.log"
                 filePattern="logs/$${date:yyyy-MM}/error-%d{yyyy-MM-dd}-%i.log.gz">
        <ThresholdFilter level="ERROR"/>
        <PatternLayout pattern="%d{yyyy-MM-dd HH:mm:ss.SSS} [%thread] [%file:%line] %-5level %logger{35} - %msg %n"/>
        <Policies>
            <SizeBasedTriggeringPolicy size="500 MB"/>
            <TimeBasedTriggeringPolicy/>
        </Policies>
    </RollingFile>
    <!--druid的日志记录追加器-->
    <RollingFile name="druidSqlRollingFile" fileName="./logs/druid-sql.log"
                 filePattern="logs/$${date:yyyy-MM}/api-%d{yyyy-MM-dd}-%i.log.gz">
        <PatternLayout pattern="%d{yyyy-MM-dd HH:mm:ss.SSS} [%thread] [%file:%line] %-5level %logger{35} - %msg %n"/>
        <Policies>
            <SizeBasedTriggeringPolicy size="500 MB"/>
            <TimeBasedTriggeringPolicy/>
        </Policies>
    </RollingFile>
</appenders>
<loggers>
    <AsyncRoot level="info">
        <appender-ref ref="Console"/>
        <appender-ref ref="RollingFileInfo"/>
        <appender-ref ref="RollingFileWarn"/>
        <appender-ref ref="RollingFileError"/>
    </AsyncRoot>
    <!--记录druid-sql的记录-->
    <AsyncLogger name="druid.sql.Statement" level="debug" additivity="false">
        <appender-ref ref="druidSqlRollingFile"/>
    </AsyncLogger>
</loggers>
</configuration>

4,数据库的相关业务表:

goods表

CREATE TABLE `goods` (
 `goodsId` bigint(11) unsigned NOT NULL AUTO_INCREMENT COMMENT 'id',
 `goodsName` varchar(500) CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci NOT NULL DEFAULT '' COMMENT 'name',
 `subject` varchar(200) NOT NULL DEFAULT '' COMMENT '标题',
 `price` decimal(15,2) NOT NULL DEFAULT '0.00' COMMENT '价格',
 `stock` int(11) NOT NULL DEFAULT '0' COMMENT 'stock',
 PRIMARY KEY (`goodsId`)
) ENGINE=InnoDB AUTO_INCREMENT=0 DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_0900_ai_ci COMMENT='商品表'

goods表中的数据:

INSERT INTO `goods` (`goodsId`, `goodsName`, `subject`, `price`, `stock`) VALUES
(3, '100分电动牙刷', '好用到让你爱上刷牙', '59.00', 96);

order表:

CREATE TABLE `orderinfo` (
 `orderId` bigint(11) unsigned NOT NULL AUTO_INCREMENT COMMENT 'id',
 `orderSn` varchar(100) NOT NULL DEFAULT '' COMMENT '编号',
 `orderTime` timestamp NOT NULL DEFAULT '1971-01-01 00:00:01' COMMENT '下单时间',
 `orderStatus` tinyint(4) NOT NULL DEFAULT '0' COMMENT '状态:0,未支付，1，已支付，2，已发货，3，已退货,4,已过期',
 `userId` int(12) NOT NULL DEFAULT '0' COMMENT '用户id',
 `price` decimal(10,0) NOT NULL DEFAULT '0' COMMENT '价格',
 `addressId` int(12) NOT NULL DEFAULT '0' COMMENT '地址',
 PRIMARY KEY (`orderId`),
 UNIQUE KEY `orderSn` (`orderSn`)
) ENGINE=InnoDB AUTO_INCREMENT=0 DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_0900_ai_ci COMMENT='订单表'

order表中的数据:

INSERT INTO `orderinfo` (`orderId`, `orderSn`, `orderTime`, `orderStatus`, `userId`, `price`, `addressId`) VALUES
(77, '20200814171411660', '2020-08-14 09:14:12', 0, 8, '100', 0);

四，java代码说明:

1,GoodsdbSourceConfig.java

@Configuration
@MapperScan(basePackages = "com.multidruid.demo.mapper.goodsdb", sqlSessionTemplateRef = "goodsdbSqlSessionTemplate")
public class GoodsdbSourceConfig {

    @Bean
    @Primary
    @ConfigurationProperties("spring.datasource.druid.goodsdb")
    public DataSource goodsdbDataSource() {
        return DruidDataSourceBuilder.create().build();
    }

    @Bean
    @Primary
    public SqlSessionFactory goodsdbSqlSessionFactory(@Qualifier("goodsdbDataSource") DataSource dataSource) throws Exception {
        SqlSessionFactoryBean bean = new SqlSessionFactoryBean();
        bean.setDataSource(dataSource);
        bean.setMapperLocations(new PathMatchingResourcePatternResolver().getResources("classpath:mapper/goodsdb/*.xml"));
        return bean.getObject();
    }

    @Bean
    @Primary
    public DataSourceTransactionManager goodsdbTransactionManager(@Qualifier("goodsdbDataSource") DataSource dataSource) {
        return new DataSourceTransactionManager(dataSource);
    }

    @Bean
    @Primary
    public SqlSessionTemplate goodsdbSqlSessionTemplate(@Qualifier("goodsdbSqlSessionFactory") SqlSessionFactory sqlSessionFactory) throws Exception {
        return new SqlSessionTemplate(sqlSessionFactory);
    }
}

说明：用basePackages指定mapper程序所在目录,

bean.setMapperLocations指定mapper的xml文件所在目录

2,OrderdbSourceConfig.java

@Configuration
@MapperScan(basePackages = "com.multidruid.demo.mapper.orderdb", sqlSessionTemplateRef = "orderdbSqlSessionTemplate")
public class OrderdbSourceConfig {

    @Bean
    @ConfigurationProperties(prefix = "spring.datasource.druid.orderdb")
    public DataSource orderdbDataSource() {
        return DruidDataSourceBuilder.create().build();
    }

    @Bean
    public SqlSessionFactory orderdbSqlSessionFactory(@Qualifier("orderdbDataSource") DataSource dataSource) throws Exception {
        SqlSessionFactoryBean bean = new SqlSessionFactoryBean();
        bean.setDataSource(dataSource);
        bean.setMapperLocations(new PathMatchingResourcePatternResolver().getResources("classpath:mapper/orderdb/*.xml"));
        return bean.getObject();
    }

    @Bean
    public DataSourceTransactionManager orderdbTransactionManager(@Qualifier("orderdbDataSource") DataSource dataSource) {
        return new DataSourceTransactionManager(dataSource);
    }

    @Bean
    public SqlSessionTemplate orderdbSqlSessionTemplate(@Qualifier("orderdbSqlSessionFactory") SqlSessionFactory sqlSessionFactory) throws Exception {
        return new SqlSessionTemplate(sqlSessionFactory);
    }
}

说明：用basePackages指定mapper程序所在目录,

bean.setMapperLocations指定mapper的xml文件所在目录

主要是把两个数据源对应的mapper接口程序和mapper的xml文件隔离开

3,GoodsMapper.java

@Repository
@Mapper
public interface GoodsMapper {
    Goods selectOneGoods(Long goodsId);
}

4,OrderMapper.java

@Repository
@Mapper
public interface OrderMapper {
    Order selectOneOrder(Long orderId);
}

5,GoodsMapper.xml

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper
        PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.multidruid.demo.mapper.goodsdb.GoodsMapper">
    <select id="selectOneGoods" parameterType="long" resultType="com.multidruid.demo.pojo.Goods">
        select * from goods where goodsId=#{goodsId}
    </select>
</mapper>

6,OrderMapper.xml

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper
        PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.multidruid.demo.mapper.orderdb.OrderMapper">
    <select id="selectOneOrder" parameterType="long" resultType="com.multidruid.demo.pojo.Order">
        select * from orderinfo where orderId=#{orderId}
    </select>
</mapper>

7,HomeController.java

@Controller
@RequestMapping("/home")
public class HomeController {

    @Resource
    private GoodsMapper goodsMapper;

    @Resource
    private OrderMapper orderMapper;

    //商品详情 参数:商品id
    @GetMapping("/goodsinfo")
    @ResponseBody
    public Goods goodsInfo(@RequestParam(value="goodsid",required = true,defaultValue = "0") Long goodsId) {
        Goods goods = goodsMapper.selectOneGoods(goodsId);
        return goods;
    }

    //订单详情 参数:订单id
    @GetMapping("/orderinfo")
    @ResponseBody
    public Order orderInfo(@RequestParam(value="orderid",required = true,defaultValue = "0") Long orderId) {
        Order order = orderMapper.selectOneOrder(orderId);
        return order;
    }
}

8，Goods/Order  两个pojo类很简单，不列出了，大家可以访问github查看

五，测试效果:

1,查询商品信息，访问：

http://127.0.0.1:8080/home/goodsinfo?goodsid=3

返回:

{"goodsId":3,"goodsName":"100分电动牙刷","subject":"好用到让你爱上刷牙","price":59.00,"stock":96}

2,查询订单信息，访问:

http://127.0.0.1:8080/home/orderinfo?orderid=77

返回：

{"orderId":77,"orderSn":"20200814171411660","orderTime":"2020-08-14 17:14:12","orderStatus":0,"userId":8,"price":100}

3,查看druid监控页面中连接到的数据源

可以看到已连接到的两个数据源

六,查看spring boot的版本

  .   ____          _            __ _ _
 /\\ / ___'_ __ _ _(_)_ __  __ _ \ \ \ \
( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
 \\/  ___)| |_)| | | | | || (_| |  ) ) ) )
  '  |____| .__|_| |_|_| |_\__, | / / / /
 =========|_|==============|___/=/_/_/_/
 :: Spring Boot ::        (v2.3.2.RELEASE)