Spring Boot教程 - 整合MyBatis 多数据源

作者: FX_SKY | 来源:发表于2017-08-17 13:27 被阅读1492次

Spring Boot教程 - 整合Mybatis（注解方式）
Spring boot + Mybatis 整合（Intelli
spring-mybatis整合
mybatis多数据源配置并初始化数据库
Spring Boot Mybatis集成
Spring Boot - XML配置的方式整合MyBatis
Spring Boot整合MyBatis
简单快捷的在SpringBoot中搭建MyBatis(只需四步)
Spring Boot中使用MyBatis
Spring Boot集成Mybatis双数据源

日常开发中，我们可能需要连接多个数据源，例如数据库进行了主从配置，写操作走主库，读操作走从库。本来结合Spring Boot + MyBatis + Druid 来演示如何配置多个数据源。

1. pom.xml

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <!-- Inherit defaults from Spring Boot -->
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>1.5.6.RELEASE</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <artifactId>spring-boot-mybatis3-multi-datasource</artifactId>
    <packaging>jar</packaging>

    <name>spring-boot-mybatis3-multi-datasource</name>
    <url>http://maven.apache.org</url>

    <properties>
        <mybatis.spring.boot.version>1.3.0</mybatis.spring.boot.version>
        <druid.version>1.0.25</druid.version>
        <mysql.connector.version>5.1.39</mysql.connector.version>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <!--mybatis-->
        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>${mybatis.spring.boot.version}</version>
        </dependency>

        <!-- db-->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>${mysql.connector.version}</version>
        </dependency>

        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid</artifactId>
            <version>${druid.version}</version>
        </dependency>
    </dependencies>

    <build>
        <finalName>spring-boot-mybatis3-multi-datasource</finalName>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
                <configuration>
                    <classifier>exec</classifier>
                </configuration>
            </plugin>
        </plugins>
    </build>
</project>

2. application.properties

mybatis.config-locations=classpath:mybatis-config.xml

spring.datasource.master.driverClassName=com.mysql.jdbc.Driver
spring.datasource.master.url=jdbc:mysql://localhost:3306/demo?useUnicode=true&characterEncoding=utf-8
spring.datasource.master.username=root
spring.datasource.master.password=root

spring.datasource.slave.driverClassName=com.mysql.jdbc.Driver
spring.datasource.slave.url=jdbc:mysql://localhost:3306/demo?useUnicode=true&characterEncoding=utf-8
spring.datasource.slave.username=root
spring.datasource.slave.password=root

3. 数据源配置

多数据源配置的时候注意，必须要有一个主数据源（使用 @Primary 标识），本例中即 MasterDataSourceConfig 配置：

package com.mindflow.springboot.mybatis.config.datasource;

import com.alibaba.druid.pool.DruidDataSource;
import org.apache.ibatis.session.SqlSessionFactory;
import org.mybatis.spring.SqlSessionFactoryBean;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.beans.factory.annotation.Value;
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 org.springframework.jdbc.datasource.DataSourceTransactionManager;
import javax.sql.DataSource;

/**
 * @author Ricky Fung
 */
@Configuration
@MapperScan(basePackages = MasterDataSourceConfig.PACKAGE, sqlSessionFactoryRef = "masterSqlSessionFactory")
public class MasterDataSourceConfig {

    static final String PACKAGE = "com.mindflow.springboot.mybatis.mapper.master";
    static final String MAPPER_LOCATION = "classpath:mapper/master/*.xml";

    @Value("${spring.datasource.master.url}")
    private String url;

    @Value("${spring.datasource.master.username}")
    private String user;

    @Value("${spring.datasource.master.password}")
    private String password;

    @Value("${spring.datasource.master.driverClassName}")
    private String driverClass;

    @Bean(name = "masterDataSource")
    @Primary
    public DataSource masterDataSource() {
        DruidDataSource dataSource = new DruidDataSource();
        dataSource.setDriverClassName(driverClass);
        dataSource.setUrl(url);
        dataSource.setUsername(user);
        dataSource.setPassword(password);
        dataSource.setInitialSize(5);
        dataSource.setMaxActive(50);
        dataSource.setMinIdle(0);
        return dataSource;
    }

    @Bean(name = "masterTransactionManager")
    @Primary
    public DataSourceTransactionManager masterTransactionManager() {
        return new DataSourceTransactionManager(masterDataSource());
    }

    @Bean(name = "masterSqlSessionFactory")
    @Primary
    public SqlSessionFactory masterSqlSessionFactory(@Qualifier("masterDataSource") DataSource masterDataSource)
            throws Exception {
        final SqlSessionFactoryBean sessionFactory = new SqlSessionFactoryBean();
        sessionFactory.setDataSource(masterDataSource);
        sessionFactory.setMapperLocations(new PathMatchingResourcePatternResolver()
                .getResources(MasterDataSourceConfig.MAPPER_LOCATION));
        return sessionFactory.getObject();
    }
}

@Primary 标志这个 Bean 如果在多个同类 Bean 候选时，该 Bean 优先被考虑。「多数据源配置的时候注意，必须要有一个主数据源，用 @Primary 标志该 Bean」；
@MapperScan 扫描 Mapper 接口并容器管理，包路径精确到 master，为了和下面 slave数据源做到精确区分；
sqlSessionFactoryRef 表示定义了 key ，表示一个唯一 SqlSessionFactory 实例。

同理，SlaveDataSourceConfig 如下：

package com.mindflow.springboot.mybatis.config.datasource;

import com.alibaba.druid.pool.DruidDataSource;
import org.apache.ibatis.session.SqlSessionFactory;
import org.mybatis.spring.SqlSessionFactoryBean;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.core.io.support.PathMatchingResourcePatternResolver;
import org.springframework.jdbc.datasource.DataSourceTransactionManager;

import javax.sql.DataSource;

/**
 * @author Ricky Fung
 */
@Configuration
@MapperScan(basePackages = SlaveDataSourceConfig.PACKAGE, sqlSessionFactoryRef = "slaveSqlSessionFactory")
public class SlaveDataSourceConfig {
    static final String PACKAGE = "com.mindflow.springboot.mybatis.mapper.slave";
    static final String MAPPER_LOCATION = "classpath:mapper/slave/*.xml";

    @Value("${spring.datasource.slave.url}")
    private String url;

    @Value("${spring.datasource.slave.username}")
    private String user;

    @Value("${spring.datasource.slave.password}")
    private String password;

    @Value("${spring.datasource.slave.driverClassName}")
    private String driverClass;

    @Bean(name = "slaveDataSource")
    public DataSource clusterDataSource() {
        DruidDataSource dataSource = new DruidDataSource();
        dataSource.setDriverClassName(driverClass);
        dataSource.setUrl(url);
        dataSource.setUsername(user);
        dataSource.setPassword(password);
        dataSource.setInitialSize(5);
        dataSource.setMaxActive(50);
        return dataSource;
    }

    @Bean(name = "slaveTransactionManager")
    public DataSourceTransactionManager clusterTransactionManager() {
        return new DataSourceTransactionManager(clusterDataSource());
    }

    @Bean(name = "slaveSqlSessionFactory")
    public SqlSessionFactory clusterSqlSessionFactory(@Qualifier("slaveDataSource") DataSource clusterDataSource)
            throws Exception {
        final SqlSessionFactoryBean sessionFactory = new SqlSessionFactoryBean();
        sessionFactory.setDataSource(clusterDataSource);
        sessionFactory.setMapperLocations(new PathMatchingResourcePatternResolver()
                .getResources(SlaveDataSourceConfig.MAPPER_LOCATION));
        return sessionFactory.getObject();
    }
}

4. service层

service照常注入了两个 DAO，如同以前一样正常工作。不用关心和指定到具体说明数据源。

UserService :

package com.mindflow.springboot.mybatis.service.impl;

import com.mindflow.springboot.mybatis.domain.UserDO;
import com.mindflow.springboot.mybatis.domain.UserDOExample;
import com.mindflow.springboot.mybatis.mapper.master.UserDOMapper;
import com.mindflow.springboot.mybatis.service.UserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import java.util.List;

/**
 * @author Ricky Fung
 */
@Service
public class UserServiceImpl implements UserService {
    @Autowired
    private UserDOMapper userDOMapper;

    @Override
    public UserDO getUserByName(String username) {
        UserDOExample example = new UserDOExample();
        List<UserDO> list = userDOMapper.selectByExample(example);
        if(list==null || list.isEmpty()) {
            return null;
        }
        return list.get(0);
    }

    @Override
    public int insert(UserDO userDO) {
        return userDOMapper.insertSelective(userDO);
    }
}

OrderService :

package com.mindflow.springboot.mybatis.service.impl;

import com.mindflow.springboot.mybatis.domain.OrderDO;
import com.mindflow.springboot.mybatis.domain.OrderDOExample;
import com.mindflow.springboot.mybatis.mapper.slave.OrderDOMapper;
import com.mindflow.springboot.mybatis.service.OrderService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.util.List;

/**
 * @author Ricky Fung
 */
@Service
public class OrderServiceImpl implements OrderService {

    @Autowired
    private OrderDOMapper orderDOMapper;

    @Override
    public List<OrderDO> getOrders(Long userId) {
        OrderDOExample example = new OrderDOExample();
        example.createCriteria().andUserIdEqualTo(userId);
        return orderDOMapper.selectByExample(example);
    }

    @Override
    public int insert(OrderDO orderDO) {
        return orderDOMapper.insert(orderDO);
    }
}

源码

spring-boot-tutorials

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