SpringBoot+Mybatis+Durid整合多数据源的三种方式，第一种

概述：项目在研发过程会遇到读取多个数据库的情况，这个时候就需要动态切换数据源用于适应系统的需求，下面我介绍三种实现方式（原理就是两种）;
废话少说，上硬货！！
第一步：pom引入依赖：
<java.version>1.8</java.version>

<dependencies>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
    </dependency>
    <dependency>
        <groupId>org.mybatis.spring.boot</groupId>
        <artifactId>mybatis-spring-boot-starter</artifactId>
        <version>2.1.2</version>
    </dependency>
    <!-- https://mvnrepository.com/artifact/org.springframework.boot/spring-boot-starter-tomcat -->
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-tomcat</artifactId>
        <version>2.2.4.RELEASE</version>
        <scope>provided</scope>
    </dependency>

    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-devtools</artifactId>
        <scope>runtime</scope>
        <optional>true</optional>
    </dependency>
    <!--<dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
        <scope>runtime</scope>
    </dependency>-->
    <!-- runtime 会引发问题，所以使用下面依赖，规定版本 -->
    <dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
        <version>8.0.15</version>
    </dependency>
    <dependency>
        <groupId>com.alibaba</groupId>
        <artifactId>druid-spring-boot-starter</artifactId>
        <version>1.1.10</version>
    </dependency>

    <dependency>
        <groupId>javax.servlet</groupId>
        <artifactId>jstl</artifactId>
        <version>1.2</version>
        <scope>provided</scope>
    </dependency>

    <dependency>
        <groupId>org.apache.tomcat.embed</groupId>
        <artifactId>tomcat-embed-jasper</artifactId>
        <version>9.0.19</version>
        <scope>provided</scope>
    </dependency>
    <dependency>
        <groupId>org.projectlombok</groupId>
        <artifactId>lombok</artifactId>
        <optional>true</optional>
    </dependency>
    <dependency>
        <groupId>com.github.pagehelper</groupId>
        <artifactId>pagehelper-spring-boot-starter</artifactId>
        <version>1.2.4</version>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-test</artifactId>
        <scope>test</scope>
        <exclusions>
            <exclusion>
                <groupId>org.junit.vintage</groupId>
                <artifactId>junit-vintage-engine</artifactId>
            </exclusion>
        </exclusions>
    </dependency>
</dependencies>

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

第二步：yml配置：需要配置连接池另行百度。

server:
  port: 9090
pagehelper:
  helper‐dialect: mysql
spring:
  datasource:
    arraign:
      jdbc-url: jdbc:mysql://------/arraign?characterEncoding=utf-8
      username: yctx
      password: password
      driverClassName: com.mysql.cj.jdbc.Driver
    dzbl:
      jdbc-url: jdbc:mysql://------/dzbl?characterEncoding=utf-8
      username: dzbl
      password: password
      driverClassName: com.mysql.cj.jdbc.Driver
mybatis:
  type-aliases-package: com.alimather.myitem.bean
  mapper-locations: mapper/*.xml

下面进入正题：
第一种实现方式，通过不同包下来读取不同数据源（分包：）
我的文件路径：

1.DataSource配置类：
<1.>DataSourceConfigToArraign

package com.alimather.myitem.datasourceconfig;

import org.apache.ibatis.session.SqlSessionFactory;
import org.mybatis.spring.SqlSessionFactoryBean;
import org.mybatis.spring.SqlSessionTemplate;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.boot.jdbc.DataSourceBuilder;
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;

/**
 * 任务:
 * 描述:
 * 作者:YJG86166
 * 日期:2020/5/20 8:19
 * @author 86166
 */
@Configuration
@MapperScan(basePackages = "com.alimather.myitem.mapper.arraignsource", sqlSessionFactoryRef = "arraignSqlSessionFactory")
public class DataSourceConfigToArraign {
    @Bean(name = "arraignDataSource")
    @Primary
    /** prefix表示参数的前缀*/
    @ConfigurationProperties(prefix = "spring.datasource.arraign")
    public DataSource getDateSourceArraign() {
        return DataSourceBuilder.create().build();
    }
    @Bean(name = "arraignSqlSessionFactory")
    @Primary
    /** @Qualifier表示查找Spring容器中名字为arraignDataSource的对象*/
    public SqlSessionFactory arraignSqlSessionFactory(@Qualifier("arraignDataSource") DataSource datasource)
            throws Exception {
        SqlSessionFactoryBean bean = new SqlSessionFactoryBean();
        bean.setDataSource(datasource);
        bean.setMapperLocations(
        // 设置mybatis的xml所在位置
        new PathMatchingResourcePatternResolver().getResources("classpath*:mapper/arraignmapper/*.xml"));
        return bean.getObject();
    }
    @Bean("arraignSqlSessionTemplate")
    @Primary
    public SqlSessionTemplate arraignSqlSessionTemplate(
            @Qualifier("arraignSqlSessionFactory") SqlSessionFactory sessionfactory) {
        return new SqlSessionTemplate(sessionfactory);
    }
}

<2.>DataSourceConfigToDzbl

package com.alimather.myitem.datasourceconfig;

import org.apache.ibatis.session.SqlSessionFactory;
import org.mybatis.spring.SqlSessionFactoryBean;
import org.mybatis.spring.SqlSessionTemplate;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.boot.jdbc.DataSourceBuilder;
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;

/**
 * 任务:
 * 描述:
 * 作者:YJG
 * 日期:2020/5/20 8:19
 * @author 86166
 */
@Configuration
@MapperScan(basePackages = "com.alimather.myitem.mapper.dzblsource", sqlSessionFactoryRef = "dzblSqlSessionFactory")
public class DataSourceConfigToDzbl {
    @Bean(name = "dzblDataSource")
    /** prefix表示参数的前缀*/
    @ConfigurationProperties(prefix = "spring.datasource.dzbl")
    public DataSource getDateSourceDzbl() {
        return DataSourceBuilder.create().build();
    }
    @Bean(name = "dzblSqlSessionFactory")
    /** @Qualifier表示查找Spring容器中名字为dzblDataSource的对象*/
    public SqlSessionFactory dzblSqlSessionFactory(@Qualifier("dzblDataSource") DataSource datasource)
            throws Exception {
        SqlSessionFactoryBean bean = new SqlSessionFactoryBean();
        bean.setDataSource(datasource);
        bean.setMapperLocations(
        // 设置mybatis的xml所在位置
        new PathMatchingResourcePatternResolver().getResources("classpath*:mapper/dzblmapper/*.xml"));
        return bean.getObject();
    }
    @Bean("dzblSqlSessionTemplate")
    public SqlSessionTemplate dzblSqlSessionTemplate(
            @Qualifier("dzblSqlSessionFactory") SqlSessionFactory sessionfactory) {
        return new SqlSessionTemplate(sessionfactory);
    }
}

2.开始使用：<service层>

package com.alimather.myitem.service;

import com.alimather.myitem.bean.SysAclModule;
import com.alimather.myitem.mapper.dzblsource.SysAclModuleMapper;
import com.github.pagehelper.Page;
import com.github.pagehelper.PageHelper;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.util.HashMap;
import java.util.List;

/**
 * 任务:
 * 描述:
 * 作者:YJG86166
 * 日期:2020/5/20 9:05
 * @author 86166
 */
@Service
public class SysAclModuleService {

    @Autowired
    private SysAclModuleMapper sysAclModuleMapper;

    public HashMap<String,Object> listSysAclModule(int page,int size){
        HashMap<String,Object> map = new HashMap<>(2);
        PageHelper.startPage(page,size);
        Page<SysAclModule> sysAclModulePage = sysAclModuleMapper.listSysAclModule();
        List<SysAclModule> sysAclModules = sysAclModulePage.getResult();
        long total = sysAclModulePage.getTotal();
        map.put("data",sysAclModules);
        map.put("total",total);
        return map;
    }

}

<mapper层>

package com.alimather.myitem.mapper.arraignsource;

import com.alimather.myitem.bean.SysAcl;
import com.github.pagehelper.Page;
import org.apache.ibatis.annotations.Mapper;

/**
 * @author 86166
 */
@Mapper
public interface SysAclMapper {
    /**获取表信息
     * @return 分页表信息*/
    Page<SysAcl> listSysAcl();
}