springboot2.1.5 + mybatis 配置多数据源

一、启动是创建bean的方式

pom.xml

<dependency>
   <groupId>com.alibaba</groupId>
   <artifactId>druid-spring-boot-starter</artifactId>
   <version>1.1.10</version>
</dependency>

<!-- maven仓库中没有oracle数据库驱动，这里将jar 放到工程下进行引入 -->
<dependency>
  <groupId>com.ojdbc</groupId>
  <artifactId>ojdbc</artifactId>
  <version>10.2.0.1</version>
  <scope>system</scope>
  <systemPath>${project.basedir}/src/main/lib/ojdbc14-10.2.0.1.0.jar</systemPath>
</dependency>

 <dependency>
  <groupId>mysql</groupId>
  <artifactId>mysql-connector-java</artifactId>
  <version>5.1.38</version>
</dependency>

application.properties

#oracle数据库
spring.datasource.master.url=jdbc:oracle:thin:@localhost:1521:test
spring.datasource.master.username=oracle
spring.datasource.master.password=123456
spring.datasource.master.driverClassName=oracle.jdbc.OracleDriver
spring.datasource.master.initialSize=5
spring.datasource.master.maxActive=15
spring.datasource.master.minIdle=5
spring.datasource.master.poolPreparedStatements=true
spring.datasource.master.validationQuery=SELECT 1 FROM DUAL

#mysql数据库
spring.datasource.slave.url=jdbc:mysql://localhost:3306/test?characterEncoding=utf8
spring.datasource.slave.username=mysql
spring.datasource.slave.password=123456
spring.datasource.slave.driverClassName=com.mysql.cj.jdbc.Driver
spring.datasource.slave.initialSize=5
spring.datasource.slave.maxActive=15
spring.datasource.slave.minIdle=5
spring.datasource.slave.poolPreparedStatements=true
spring.datasource.slave.validationQuery=SELECT 1

MasterDataSourceConfig.java

注：Primary注解代表改数据源为主数据源

package com.core.dataSource;

import com.alibaba.druid.spring.boot.autoconfigure.DruidDataSourceBuilder;
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.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;

/**
 * oracle数据配置
 */
@Configuration
//配置mapper文件目录，进行扫描
@MapperScan(basePackages = "com.wawj.core.mapper.master", sqlSessionTemplateRef = "masterSqlSessionTemplate")
public class MasterDataSourceConfig {

    /**
     * 创建数据源
     * @return
     */
    @Bean
    @Primary
    @ConfigurationProperties(prefix = "spring.datasource.master")
    public DataSource masterDataSource() {
        return DruidDataSourceBuilder.create().build();
    }

    /**
     * 创建工厂
     * @param dataSource
     * @return
     * @throws Exception
     */
    @Bean
    @Primary
    public SqlSessionFactory masterSqlSessionFactory(@Qualifier("masterDataSource") DataSource dataSource) throws Exception {
        SqlSessionFactoryBean bean = new SqlSessionFactoryBean();
        bean.setDataSource(dataSource);
        //指定mapper.xml的目录
        bean.setMapperLocations(new PathMatchingResourcePatternResolver().getResources("classpath:mapper/master/**/*.xml"));
        //指定实体类目录
        bean.setTypeAliasesPackage("com.wawj.core.entity");
        return bean.getObject();
    }

    /**
     * 创建事务
     * @param dataSource
     * @return
     */
    @Bean
    @Primary
    public DataSourceTransactionManager masterTransactionManager(@Qualifier("masterDataSource") DataSource dataSource) {
        return new DataSourceTransactionManager(dataSource);
    }

    /**
     * 创建模板
     * @param sqlSessionFactory
     * @return
     */
    @Bean
    @Primary
    public SqlSessionTemplate masterSqlSessionTemplate(@Qualifier("masterSqlSessionFactory") SqlSessionFactory sqlSessionFactory) {
        return new SqlSessionTemplate(sqlSessionFactory);
    }

}

SlaveDataSourceConfig.java

package com.core.dataSource;

import com.alibaba.druid.spring.boot.autoconfigure.DruidDataSourceBuilder;
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.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;

/**
 * oracle数据配置
 */
@Configuration
//配置mapper文件目录，进行扫描
@MapperScan(basePackages = "com.wawj.core.mapper.slave", sqlSessionTemplateRef = "slaveSqlSessionTemplate")
public class SlaveDataSourceConfig {

    /**
     * 创建数据源
     * @return
     */
    @Bean
    @ConfigurationProperties(prefix = "spring.datasource.slave")
    public DataSource slaveDataSource() {
        return DruidDataSourceBuilder.create().build();
    }

    /**
     * 创建工厂
     * @param dataSource
     * @return
     * @throws Exception
     */
    @Bean
    public SqlSessionFactory slaveSqlSessionFactory(@Qualifier("slaveDataSource") DataSource dataSource) throws Exception {
        SqlSessionFactoryBean bean = new SqlSessionFactoryBean();
        bean.setDataSource(dataSource);
        //指定mapper.xml的目录
        bean.setMapperLocations(new PathMatchingResourcePatternResolver().getResources("classpath:mapper/slave/**/*.xml"));
        //指定实体类目录
        bean.setTypeAliasesPackage("com.wawj.core.entity");
        return bean.getObject();
    }

    /**
     * 创建事务
     * @param dataSource
     * @return
     */
    @Bean
    public DataSourceTransactionManager slaveTransactionManager(@Qualifier("slaveDataSource") DataSource dataSource) {
        return new DataSourceTransactionManager(dataSource);
    }

    /**
     * 创建模板
     * @param sqlSessionFactory
     * @return
     */
    @Bean
    public SqlSessionTemplate slaveSqlSessionTemplate(@Qualifier("slaveSqlSessionFactory") SqlSessionFactory sqlSessionFactory) {
        return new SqlSessionTemplate(sqlSessionFactory);
    }

}

这种方式初始化的是时候在druid控制台（http://localhost:8080/druid/login.html）中的数据源标签是没有，要请求过后才会显示当前连接的数据源

二、使用dynamic-datasource 动态配置（相当于与spring一起创建）

pom.xml

<dependency>
   <groupId>com.alibaba</groupId>
   <artifactId>druid-spring-boot-starter</artifactId>
   <version>1.1.10</version>
</dependency>

<dependency>
   <groupId>com.baomidou</groupId>
   <artifactId>dynamic-datasource-spring-boot-starter</artifactId>
   <version>2.5.6</version>
</dependency>

<!-- maven仓库中没有oracle数据库驱动，这里将jar 放到工程下进行引入 -->
<dependency>
   <groupId>com.ojdbc</groupId>
   <artifactId>ojdbc</artifactId>
   <version>10.2.0.1</version>
   <scope>system</scope>
   <systemPath>${project.basedir}/src/main/lib/ojdbc14-10.2.0.1.0.jar</systemPath>
</dependency>

<dependency>
   <groupId>mysql</groupId>
   <artifactId>mysql-connector-java</artifactId>
   <version>5.1.38</version>
</dependency>

application.properties

#全局默认值，可以全局更改
spring.datasource.dynamic.druid.initial-size=5
spring.datasource.dynamic.druid.max-active=5
spring.datasource.dynamic.druid.min-idle=5
spring.datasource.dynamic.druid.pool-prepared-statements=true

#oracle数据库
spring.datasource.dynamic.datasource.master.driver-class-name=oracle.jdbc.OracleDriver
spring.datasource.dynamic.datasource.master.druid.validation-query=SELECT 1 FROM DUAL
spring.datasource.dynamic.datasource.master.url=jdbc:oracle:thin:@localhost:1521:test
spring.datasource.dynamic.datasource.master.username=oracle
spring.datasource.dynamic.datasource.master.password=123456

#mysql数据库
spring.datasource.dynamic.datasource.slave.driver-class-name=com.mysql.cj.jdbc.Driver
spring.datasource.dynamic.datasource.slave.druid.validation-query=SELECT 1
spring.datasource.dynamic.datasource.slave.url=jdbc:mysql://localhost:3306/test?characterEncoding=utf8
spring.datasource.dynamic.datasource.slave.username=mysql
spring.datasource.dynamic.datasource.slave.password=123456

#默认aihome数据库
spring.datasource.dynamic.primary=master
#排除 原生Druid的快速配置类（DruidDataSourceAutoConfigure会注入一个DataSourceWrapper，其会在原生的spring.datasource下找url,username,password等。而我们动态数据源的配置路径是变化的。）
spring.autoconfigure.exclude=com.alibaba.druid.spring.boot.autoconfigure.DruidDataSourceAutoConfigure

#设置dynamic登录名
spring.datasource.druid.stat-view-servlet.login-username=admin
#设置dynamic密码
spring.datasource.druid.stat-view-servlet.login-password=admin

#mybatis mapper location
mybatis-plus.mapper-locations=classpath:mapper/**/*.xml
mybatis-plus.type-aliases-package=com.wawj.core.entity

这种方式使用注解（@DS("数据源名称")）切换数据源

@DS 可以注解在方法上和类上，同时存在方法注解优先于类上注解。

注解在service实现或mapper接口方法上，但强烈不建议同时在service和mapper注解。 (可能会有问题)

补充：排除原生的DruidDataSourceAutoConfigure也可以在springboot启动类排除（某些springBoot的版本上面可能无法排除就在application.properties中配置排除）

@SpringBootApplication(exclude = DruidDataSourceAutoConfigure.class)
public class Application {

  public static void main(String[] args) {
    SpringApplication.run(Application.class, args);
  }
}

或

#application.properties
spring.autoconfigure.exclude=com.alibaba.druid.spring.boot.autoconfigure.DruidDataSourceAutoConfigure