Spring boot +Mybatis 实现多数据源（一：最简单版本）

多数据源的问题在实际项目中还是经常遇到的，例如读写分离的数据库、马甲类型服务器等。不多说上干货，特别说明下本人用的开发工具是idea。
创建Spring Boot项目
菜单 file–》new –》project–》spring initializer 填写自己的group、artifact之后勾选web开启web属性数据库选着mysql、mybatis

项目初始化完成，pom中加载分页组件、数据源后如下：

<?xml version="1.0" encoding="UTF-8"?>
<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">
    <modelVersion>4.0.0</modelVersion>

    <groupId>com.rongdong</groupId>
    <artifactId>waistcoat</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>war</packaging>

    <name>waistcoat</name>
    <description></description>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.0.0.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
        <java.version>1.8</java.version>
        <mybatis.pagehelper.version>4.1.6</mybatis.pagehelper.version>
    </properties>

    <dependencies>
        <!--起步依赖-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-jdbc</artifactId>
        </dependency>
        <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>1.3.2</version>
        </dependency>
        <!--内置tomact 可有可无-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-tomcat</artifactId>
            <!--<scope>provided</scope>-->
        </dependency>
        <!--测试-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>

        <!--数据库-->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <scope>runtime</scope>
        </dependency>

        <!-- alibaba的druid数据库连接池 -->
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid</artifactId>
            <version>1.0.11</version>
        </dependency>
        <!-- alibaba的druid数据库连接池 -->
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid-spring-boot-starter</artifactId>
            <version>1.1.0</version>
        </dependency>
        <!--json 工具-->
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-core</artifactId>
        </dependency>
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-databind</artifactId>
        </dependency>
        <dependency>
            <groupId>com.fasterxml.jackson.datatype</groupId>
            <artifactId>jackson-datatype-joda</artifactId>
        </dependency>
        <dependency>
            <groupId>com.fasterxml.jackson.module</groupId>
            <artifactId>jackson-module-parameter-names</artifactId>
        </dependency>

        <!-- 分页插件 -->
        <dependency>
            <groupId>com.github.pagehelper</groupId>
            <artifactId>pagehelper</artifactId>
            <version>${mybatis.pagehelper.version}</version>
        </dependency>

        <!--基础工具-->
        <dependency>
            <groupId>org.apache.commons</groupId>
            <artifactId>commons-lang3</artifactId>
            <version>3.7</version>
        </dependency>



    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>

            <!-- mybatis generator 自动生成代码插件 -->
            <plugin>
                <groupId>org.mybatis.generator</groupId>
                <artifactId>mybatis-generator-maven-plugin</artifactId>
                <version>1.3.2</version>
                <configuration>
                    <configurationFile>${basedir}/src/main/resources/generator/generatorConfig.xml</configurationFile>
                    <overwrite>true</overwrite>
                    <verbose>true</verbose>
                </configuration>
            </plugin>
        </plugins>
    </build>


</project>

generator是自动生成mybatis 映射文件的，还不知道的可以百度下
在resouces下新建generator 文件夹并新建generator.xml文件

内容如下：

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE generatorConfiguration PUBLIC "-//mybatis.org//DTD MyBatis Generator Configuration 1.0//EN"
        "http://mybatis.org/dtd/mybatis-generator-config_1_0.dtd">

<generatorConfiguration>
    <!-- 数据库驱动:选择你的本地硬盘上面的数据库驱动包-->
    <classPathEntry location="G:\generator\mysql-connector-java-5.1.34.jar" />
    <context id="DB2Tables"  targetRuntime="MyBatis3">
        <commentGenerator>
            <property name="suppressDate" value="true"/>
            <!-- 是否去除自动生成的注释 true：是 ： false:否 -->
            <property name="suppressAllComments" value="true"/>
        </commentGenerator>
        <!--数据库链接URL，用户名、密码 -->
        <jdbcConnection driverClass="com.mysql.jdbc.Driver"
                        connectionURL="jdbc:mysql://127.0.0.1:3306/test?characterEncoding=utf8"
                        userId="root"
                        password="root">
        </jdbcConnection>
        <javaTypeResolver>
            <property name="forceBigDecimals" value="false"/>
        </javaTypeResolver>
        <!-- 生成模型的包名和位置-->
        <javaModelGenerator targetPackage="com.rongdong.model.secondDataSource" targetProject="src">
            <property name="enableSubPackages" value="true"/>
            <property name="trimStrings" value="true"/>
        </javaModelGenerator>
        <!-- 生成映射文件的包名和位置-->
        <sqlMapGenerator targetPackage="main.resources.mapping.secondDataSource" targetProject="src">
            <property name="enableSubPackages" value="true"/>
        </sqlMapGenerator>
        <!-- 生成DAO的包名和位置-->
        <javaClientGenerator type="XMLMAPPER" targetPackage="com.rongdong.dao.secondDataSource" targetProject="src">
            <property name="enableSubPackages" value="true"/>
        </javaClientGenerator>
        <!-- 要生成的表 tableName是数据库中的表名或视图名 domainObjectName是实体类名-->
        <table tableName="user_info" domainObjectName="SecondUserInfo" enableCountByExample="false" enableUpdateByExample="false" enableDeleteByExample="false" enableSelectByExample="false" selectByExampleQueryId="false" />
    </context>
</generatorConfiguration>

习惯yml格式配置文件看着清晰点，将 application改为yml 的多数据源配置如下：

server:
  port: 8089

spring:
    datasource:
      primary:
          jdbc-url:  jdbc:mysql://127.0.0.1:3306/rongdong_waistcoat_db
          username: root
          password: root

          type: com.alibaba.druid.pool.DruidDataSource
          driver-class-name: com.mysql.jdbc.Driver
          filters: stat
          maxActive: 20
          initialSize: 1
          maxWait: 60000
          minIdle: 1
          timeBetweenEvictionRunsMillis: 60000
          minEvictableIdleTimeMillis: 300000
          validationQuery: select 'x'
          testWhileIdle: true
          testOnBorrow: false
          testOnReturn: false
          poolPreparedStatements: true
          maxOpenPreparedStatements: 20
      second:
          jdbc-url:  jdbc:mysql://127.0.0.1:3306/rongdong_jtx_db
          username: root
          password:root




#mybatis:
#  mapper-locations: classpath:mapping/*.xml  #指明mapper的xml文件存放位置
#  type-aliases-package: com.rongdong.model   #指明和数据库映射的实体的所在包

#pagehelper 分页插件
pagehelper:
    helperDialect: mysql
    reasonable: true
    supportMethodsArguments: true
    params: count=countSql

然后就是配置问题，我的因为我的数据库中表名相同，但是部分字段不一样因此我在dao层、model、mapping这块给细分成了多个部分

然后新建DataSourceConfig 数据源配置类

/**
 * 数据源配置类
 *
 * @author hsh
 * @create 2018-03-21 19:06
 **/
@Configuration
public class DataSourceConfig {

    @Bean(name = "primaryDataSource")
    @Qualifier("primaryDataSource")
    @ConfigurationProperties(prefix="spring.datasource.primary")
    public DataSource primaryDataSource() {
        return DataSourceBuilder.create().build();
    }

    @Bean(name = "secondDataSource")
    @ConfigurationProperties(prefix = "spring.datasource.second") // application.properteis中对应属性的前缀
    public DataSource dataSource2() {
        return DataSourceBuilder.create().build();
    }
}

配置具体数据源
数据源A

/**
 * Mybatis SqlSessionFactory多数据源配置
 *
 * @author hsh
 * @create 2018-03-21 19:18
 **/
@Configuration
@MapperScan(basePackages = {"com.rongdong.dao.priDataSource"}, sqlSessionFactoryRef = "sqlSessionFactory1")
public class MybatisDbAConfig {

    public static final String MAPPER_LOCATION = "classpath:mapping/priDataSource/*.xml";

    @Autowired
    @Qualifier("primaryDataSource")
    private DataSource ds1;


    @Bean
    public SqlSessionFactory sqlSessionFactory1() throws Exception {
        SqlSessionFactoryBean factoryBean = new SqlSessionFactoryBean();
        factoryBean.setDataSource(ds1); // 使用主数据源, 连接主库
        Resource[] resource = new PathMatchingResourcePatternResolver().getResources(MybatisDbAConfig.MAPPER_LOCATION);
        factoryBean.setMapperLocations(resource);
        return factoryBean.getObject();

    }

    @Bean
    public SqlSessionTemplate sqlSessionTemplate1() throws Exception {
        return new SqlSessionTemplate(sqlSessionFactory1());
    }
}

数据源B

/**
 * Mybatis SqlSessionFactory多数据源配置
 *
 * @author hsh
 * @create 2018-03-21 19:48
 **/
@Configuration
@MapperScan(basePackages = {"com.rongdong.dao.secondDataSource"}, sqlSessionFactoryRef = "sqlSessionFactory2")
public class MybatisDbBConfig {
    public static final String MAPPER_LOCATION = "classpath:mapping/secondDataSource/*.xml";

    @Autowired
    @Qualifier("secondDataSource")
    private DataSource ds2;

    @Bean
    public SqlSessionFactory sqlSessionFactory2() throws Exception {
        SqlSessionFactoryBean factoryBean = new SqlSessionFactoryBean();
        factoryBean.setDataSource(ds2);
        Resource[] resource = new PathMatchingResourcePatternResolver().getResources(MybatisDbBConfig.MAPPER_LOCATION);
        factoryBean.setMapperLocations(resource);
        return factoryBean.getObject();

    }

    @Bean
    public SqlSessionTemplate sqlSessionTemplate2() throws Exception {
        SqlSessionTemplate template = new SqlSessionTemplate(sqlSessionFactory2());
        return template;
    }
}

service 层具体调用了

/**
 * 用户service实现
 *
 * @author hsh
 * @create 2018-03-21 17:44
 **/
@Service
public class UserServiceImpl implements UserService {

    @Autowired
    private UserInfoMapper userInfoMapper;

    @Autowired
    private SecondUserInfoMapper secondUserInfoMapper;

    @Override
    public UserInfo getUserById(String userId, Integer dataSourceType) throws Exception {
        if (dataSourceType == DataSourceTypeEnum.one.getIndex()) {
            return userInfoMapper.selectByPrimaryKey(userId);
        } else if (dataSourceType == DataSourceTypeEnum.two.getIndex()) {
            UserInfo userInfoTar = new UserInfo();
            SecondUserInfo secondUserInfo = secondUserInfoMapper.selectByPrimaryKey(userId);
            BeanUtils.copyProperties(secondUserInfo, userInfoTar);
            return userInfoTar;
        }
        return null;
    }
}

controller代码

@RestController
@RequestMapping(value = "/user")
public class UserController {

    @Autowired
    private UserService userService;

    @RequestMapping(value = "{id}/{datatype}", method = RequestMethod.GET)
    public UserInfo getUserById(@PathVariable("id") String userId,@PathVariable("datatype") Integer dataType) throws Exception {
        return userService.getUserById(userId, dataType);
    }



}

调试

搞定！
1。提醒下spring boot 2.0之后多数据的配置url时候要用 jdbc-url替代url不然报错

jdbcUrl is required with driverClassName.

2。表名相同的情况下 dao层是不能名字一样的，因为默认是name实例化这个bean 会报错因此实例化

以上就是最简单版本的Spring boot +Mybatis 实现多数据源，当然还有动态绑定数据源的，后期有时间在继续更新上来，欢迎大家指正！有问题的可以留言大家互相交流下！

Spring boot +Mybatis 实现多数据源（一：最简单版本）

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