springboot配置双数据源（Mybatis）

雨点打透心脏的1/2处 2024-04-18 18:32 87阅读 0赞

### 文章目录 ###

*   *   *   *  背景介绍
             *  实现思路
             *  环境介绍
             *  实现步骤
             *   *  1、配置数据库信息
                 *  2、数据源配置文件
                 *  3、补全其他组件代码
                 *   *  bean包，里面随意放了两个简单的类
                     *  mapper包
                     *  dao包
                     *  service包
                     *  controller包
                     *  启动类
                     *  资源包
                     *  pom文件
             *  总结

#### 背景介绍 ####

最近的项目需求，需要将两个现有项目进行整合，原因是跨系统访问数据库，使用接口稍显复杂，而且还得不停的维护接口，所以想采取双数据源方案解决。由此，在网上查资料，自己写了个demo，仅供参考。

#### 实现思路 ####

**分包思想，将涉及到数据库操作的代码分别放到两个包，在数据源的配置文件中，指定扫描的路径即可，下面来操作一下**

--------------------

#### 环境介绍 ####

*  springboot2.1.6（直接从springboot官网下载的，可以参考官网部署）
 *  MySQL8.0（使用select version(); 查询当前版本）
 *  代码结构预览  
    ![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3NoZW56aG91X3lo_size_16_color_FFFFFF_t_70]

#### 实现步骤 ####

##### 1、配置数据库信息 #####

## test1 database
    spring.datasource.test1.jdbc-url=jdbc:mysql://localhost:3306/aipc-sit?useUnicode=true&characterEncoding=UTF-8&serverTimezone=UTC&useSSL=false
    spring.datasource.test1.username=root
    spring.datasource.test1.password=123456
    spring.datasource.test1.driver-class-name=com.mysql.jdbc.Driver
    ## test2 database
    spring.datasource.test2.jdbc-url=jdbc:mysql://localhost:3306/aipc-uat?useUnicode=true&characterEncoding=UTF-8&serverTimezone=UTC&useSSL=false
    spring.datasource.test2.username=root
    spring.datasource.test2.password=123456
    spring.datasource.test2.driver-class-name=com.mysql.jdbc.Driver

*  注意一下：url和驱动名称的命名写法，如果启动时报jdbcUrl is required with driverClassName错误，参考我之前的博客[springboot启动报错——jdbcUrl is required with driverClassName][springboot_jdbcUrl is required with driverClassName]

##### 2、数据源配置文件 #####

这个步骤是比较核心的，主要是用来扫描不同路径的的mapper来实现双库查询，注意其中包名的的指定。

*  配置第一个数据源：DataSourceConfig1 .java

package com.shenzhouyh.multiDataSource.dataSource;
    
    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;
    
    /** * @author: yinhao * @date:2019/9/9 * @time:9:54 * @desciption */
    //表示这个类为一个配置类
    @Configuration
    // 配置mybatis的接口类放的地方
    @MapperScan(basePackages = "com.shenzhouyh.multiDataSource.mapper.test01", sqlSessionFactoryRef = "test1SqlSessionFactory") public class DataSourceConfig1 { 
    	// 将这个对象放入Spring容器中
    	@Bean(name = "test1DataSource")
    	// 表示这个数据源是默认数据源
    	@Primary
    	// 读取application.properties中的配置参数映射成为一个对象
    	// prefix表示参数的前缀
    	@ConfigurationProperties(prefix = "spring.datasource.test1") public DataSource getDateSource1() { 
    		return DataSourceBuilder.create().build();
    	}
    
    	@Bean(name = "test1SqlSessionFactory")
    	// 表示这个数据源是默认数据源
    	@Primary
    	// @Qualifier表示查找Spring容器中名字为test1DataSource的对象
    	public SqlSessionFactory test1SqlSessionFactory(@Qualifier("test1DataSource") 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*:mapping/test01/*.xml"));
    		return bean.getObject();
    	}
    
    	@Bean("test1SqlSessionTemplate")
    	// 表示这个数据源是默认数据源
    	@Primary public SqlSessionTemplate test1sqlsessiontemplate(
    			@Qualifier("test1SqlSessionFactory") SqlSessionFactory sessionfactory) { 
    		return new SqlSessionTemplate(sessionfactory);
    	}
    }

如果是自己搭建的话，这块建议直接复制，里面已经有了较为详细的说明，只要注意扫描的文件路径即可。**@Primary**标签不可缺少，指明了默认数据源。

*  配置第二个数据源文件：DataSourceConfig2.java

package com.shenzhouyh.multiDataSource.dataSource;
    
    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.core.io.support.PathMatchingResourcePatternResolver;
    
    import javax.sql.DataSource;
    
    /** * @author: yinhao * @date:2019/9/9 * @time:11:41 * @desciption */
    @Configuration @MapperScan(basePackages = "com.shenzhouyh.multiDataSource.mapper.test02", sqlSessionFactoryRef = "test2SqlSessionFactory") public class DataSourceConfig2 { 
    	@Bean(name = "test2DataSource") @ConfigurationProperties(prefix = "spring.datasource.test2") public DataSource getDateSource2() { 
    		return DataSourceBuilder.create().build();
    	}
    
    	@Bean(name = "test2SqlSessionFactory") public SqlSessionFactory test2SqlSessionFactory(@Qualifier("test2DataSource") DataSource datasource)
    			throws Exception { 
    		SqlSessionFactoryBean bean = new SqlSessionFactoryBean();
    		bean.setDataSource(datasource);
    		bean.setMapperLocations(
    				new PathMatchingResourcePatternResolver().getResources("classpath*:mapping/test02/*.xml"));
    		return bean.getObject();
    	}
    
    	@Bean("test2SqlSessionTemplate") public SqlSessionTemplate test2sqlsessiontemplate(
    			@Qualifier("test2SqlSessionFactory") SqlSessionFactory sessionfactory) { 
    		return new SqlSessionTemplate(sessionfactory);
    	}
    }

##### 3、补全其他组件代码 #####

###### bean包，里面随意放了两个简单的类 ######

![bean包结构][bean]

*  Student.java

package com.shenzhouyh.multiDataSource.bean;
    
    import lombok.Data;
    
    /** * @author: yinhao * @date:2019/9/9 * @time:11:53 * @desciption */
     
    @Data public class Student { 
    	private String name;
    	private String studentId;
    	private String classId;
    
    	@Override public String toString() { 
    		return "student{" + "name='" + name + '\'' + ", studentId='" + studentId + '\'' + ", classId='" + classId + '\''
    				+ '}';
    	}
    }

*  Teacher.java

package com.shenzhouyh.multiDataSource.bean;
    
    import lombok.Data;
    
    /** * @author: yinhao * @date:2019/9/9 * @time:11:53 * @desciption */
    @Data public class Teacher { 
    
    	private String name;
    	private String teacherId;
    	private String classId;
    
    	@Override public String toString() { 
    		return "teacher{" + "name='" + name + '\'' + ", teacherId='" + teacherId + '\'' + ", classId='" + classId + '\''
    				+ '}';
    	}
    }

注：里面使用了lombok组件，没有使用过的童鞋建议可以了解一下，简化代码好用的一bi，还有更高阶的用法。

###### mapper包 ######

数据库的配置文件，主要就是扫描这个包下面的类  
![mapper包结构][mapper]

\-TransactionMapping1.java

package com.shenzhouyh.multiDataSource.mapper.test01;
    
    import com.shenzhouyh.multiDataSource.bean.Student;
    import org.springframework.stereotype.Repository;
    
    /** * @author: yinhao * @date:2019/9/9 * @time:12:02 * @desciption */
    @Repository public interface TransactionMapping1 { 
    	/** * 保存学生信息 * * @param student 学生实体 */
    	void save(Student student);
    }

\-TransactionMapping2.java

package com.shenzhouyh.multiDataSource.mapper.test02;
    
    import com.shenzhouyh.multiDataSource.bean.Teacher;
    import org.springframework.stereotype.Repository;
    
    /** * @author: yinhao * @date:2019/9/9 * @time:12:02 * @desciption */
    @Repository public interface TransactionMapping2 { 
    	/** * 保存老师信息 * * @param teacher 老师实体 */
    	void save(Teacher teacher);
    }

注：@Repository、@Service、@Controller 和 @Component 将类标识为Bean，作用一样，但是语义不一样，分别对应存储层Bean，业务层Bean，和展示层Bean以及通用Bean

###### dao包 ######

![dao包结构][dao]

*  TransactionDao1.java

package com.shenzhouyh.multiDataSource.dao.test01;
    
    import com.shenzhouyh.multiDataSource.bean.Student;
    import com.shenzhouyh.multiDataSource.mapper.test01.TransactionMapping1;
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.stereotype.Component;
    
    /** * @author: yinhao * @date:2019/9/9 * @time:12:09 * @desciption */
    @Component public class TransactionDao1 { 
    	@Autowired private TransactionMapping1 mapping1;
    
    	public void save(Student student) { 
    		mapping1.save(student);
    	}
    }

*  TransactionDao1.java

package com.shenzhouyh.multiDataSource.dao.test02;
    
    import com.shenzhouyh.multiDataSource.bean.Teacher;
    import com.shenzhouyh.multiDataSource.mapper.test02.TransactionMapping2;
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.stereotype.Component;
    
    /** * @author: yinhao * @date:2019/9/9 * @time:12:09 * @desciption */
    @Component public class TransactionDao2 { 
    	@Autowired private TransactionMapping2 mapping2;
    
    	public void save(Teacher teacher) { 
    		mapping2.save(teacher);
    	}
    }

###### service包 ######

![service包结构][service]

*  TransactionService1.java

package com.shenzhouyh.multiDataSource.service;
    
    import com.shenzhouyh.multiDataSource.bean.Student;
    import com.shenzhouyh.multiDataSource.dao.test01.TransactionDao1;
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.stereotype.Service;
    
    /** * @author: yinhao * @date:2019/9/9 * @time:12:25 * @desciption */
    @Service public class TransactionService1 { 
    	@Autowired private TransactionDao1 transactionDao1;
    
    	public void save(Student student) { 
    		transactionDao1.save(student);
    	}
    }

*  TransactionService2.java

package com.shenzhouyh.multiDataSource.service;
    
    import com.shenzhouyh.multiDataSource.bean.Teacher;
    import com.shenzhouyh.multiDataSource.dao.test02.TransactionDao2;
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.stereotype.Service;
    
    /** * @author: yinhao * @date:2019/9/9 * @time:12:25 * @desciption */
    @Service public class TransactionService2 { 
    	@Autowired private TransactionDao2 transactionDao2;
    
    	public void save(Teacher teacher) { 
    		transactionDao2.save(teacher);
    	}
    }

###### controller包 ######

package com.shenzhouyh.multiDataSource.controller;
    
    import com.shenzhouyh.multiDataSource.bean.Student;
    import com.shenzhouyh.multiDataSource.bean.Teacher;
    import com.shenzhouyh.multiDataSource.service.TransactionService1;
    import com.shenzhouyh.multiDataSource.service.TransactionService2;
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.bind.annotation.RestController;
    
    import java.util.UUID;
    
    /** * @author: yinhao * @date:2019/9/9 * @time:12:29 * @desciption */
    @RestController public class TransactionColler { 
    	@Autowired private TransactionService1 studentService;
    	@Autowired private TransactionService2 teacherService;
    
    	@RequestMapping(value = "saveStudent") public String saveStudent() { 
    		Student student = new Student();
    		student.setStudentId(UUID.randomUUID().toString().replaceAll("-", ""));
    		student.setClassId("一班");
    		student.setName("张三同学");
    		studentService.save(student);
    		return "success1";
    	}
    
    	@RequestMapping(value = "/saveTeacher") public String saveTeacher() { 
    		Teacher teacher = new Teacher();
    		teacher.setTeacherId(UUID.randomUUID().toString().replaceAll("-", ""));
    		teacher.setClassId("一班");
    		teacher.setName("李四老师");
    		teacherService.save(teacher);
    		return "success2";
    	}
    }

###### 启动类 ######

package com.shenzhouyh.multiDataSource;
    
    import org.mybatis.spring.annotation.MapperScan;
    import org.springframework.boot.CommandLineRunner;
    import org.springframework.boot.SpringApplication;
    import org.springframework.boot.autoconfigure.SpringBootApplication;
    import org.springframework.boot.autoconfigure.jdbc.DataSourceAutoConfiguration;
    import org.springframework.context.ApplicationContext;
    import org.springframework.context.annotation.Bean;
    
    import java.util.Arrays;
    
    @SpringBootApplication(exclude = { 
            DataSourceAutoConfiguration.class }) @MapperScan("com.shenzhouyh.multiDataSource.mapper")
    public class Application { 
    
        public static void main(String[] args) { 
            SpringApplication.run(Application.class, args);
        }
    
        @Bean
        public CommandLineRunner commandLineRunner(ApplicationContext ctx) { 
            return args -> { 
    
                System.out.println("Let's inspect the beans provided by Spring Boot:");
    
                String[] beanNames = ctx.getBeanDefinitionNames();
                Arrays.sort(beanNames);
                for (String beanName : beanNames) { 
                    System.out.println(beanName);
                }
    
            };
        }
    
    }

注意：

*  启动类的SpringBootApplication注解，相当于@Configuration,@EnableAutoConfiguration,@ComponentScan，因为他们基本一块使用，所以springboot2.0直接就进行了整合。详细请参考[SpringBootApplication的使用][SpringBootApplication]
 *  SpringBootApplication后使用exclude = \{  
    DataSourceAutoConfiguration.class \}，否则会报：Failed to determine a suitable driver class异常，原因是应用没有使用到DataSource，但是在pom.xml里引入了mybatis-spring-boot-starter，排除一个就好了。
 *  @MapperScan注解用于，要扫描mapper类包的路径,可配置多路径且可使用通配符

###### 资源包 ######

![资源包结构][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3NoZW56aG91X3lo_size_16_color_FFFFFF_t_70 1]

\-TransactionMapping1.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.shenzhouyh.multiDataSource.mapper.test01.TransactionMapping1">
        <insert id="save" parameterType="com.shenzhouyh.multiDataSource.bean.Student">
            insert into student (name,student_id,class_id) values (#{name},#{studentId},#{classId});
        </insert>
    </mapper>

TransactionMapping2.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.shenzhouyh.multiDataSource.mapper.test02.TransactionMapping2">
        <insert id="save" parameterType="com.shenzhouyh.multiDataSource.bean.Teacher">
            insert into teacher (name,teacher_id,class_id) values (#{name},#{teacherId},#{classId});
        </insert>
    </mapper>

###### pom文件 ######

<?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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
        <modelVersion>4.0.0</modelVersion>
    
        <groupId>org.springframework</groupId>
        <artifactId>gs-spring-boot</artifactId>
        <version>0.1.0</version>
    
        <parent>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-parent</artifactId>
            <version>2.1.6.RELEASE</version>
        </parent>
    
        <dependencies>
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-web</artifactId>
            </dependency>
            
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-actuator</artifactId>
            </dependency>
            
            
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-test</artifactId>
                <scope>test</scope>
            </dependency>
            
            
            <dependency>
                <groupId>ch.qos.logback</groupId>
                <artifactId>logback-classic</artifactId>
                <version>1.2.3</version>
            </dependency>
    
            <dependency>
                <groupId>org.mybatis.spring.boot</groupId>
                <artifactId>mybatis-spring-boot-starter</artifactId>
                <version>1.3.2</version>
            </dependency>
            <dependency>
                <groupId>mysql</groupId>
                <artifactId>mysql-connector-java</artifactId>
                <version>5.1.45</version>
            </dependency>
            
            <dependency>
                <groupId>org.projectlombok</groupId>
                <artifactId>lombok</artifactId>
                <version>1.16.18</version>
            </dependency>
            <dependency>
                <groupId>org.springframework</groupId>
                <artifactId>spring-context-support</artifactId>
                <version>4.2.5.RELEASE</version>
            </dependency>
        </dependencies>
    
        <properties>
            <java.version>1.8</java.version>
        </properties>
    
        <build>
            <plugins>
                <plugin>
                    <groupId>org.springframework.boot</groupId>
                    <artifactId>spring-boot-maven-plugin</artifactId>
                </plugin>
                <plugin>
                    <artifactId>maven-failsafe-plugin</artifactId>
                    <executions>
                        <execution>
                            <goals>
                                <goal>integration-test</goal>
                                <goal>verify</goal>
                            </goals>
                        </execution>
                    </executions>
                </plugin>
            </plugins>
        </build>
    
    </project>

#### 总结 ####

这个demo是网上现有的例子，我只是在本地手敲了一遍，但是不可否认，遇坑无数，老是卡壳，本文中也就挑了一个说明了一下，我也会在后面的博客中进行总结和介绍。这个demo只是一个双库查询的简单demo，距离生产操作还差的很远，最明显的一点是没有进行事务控制，我参考的大神文章中都有介绍，除了这种方式之外，还有好多种方案，比如AOP请求拦截等分割数据源。还需努力啊！！！

**本文主要参考**  
https://blog.csdn.net/tuesdayma/article/details/81081666，推荐一下，里面还提供了github地址，多向大佬学习。

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3NoZW56aG91X3lo_size_16_color_FFFFFF_t_70]: https://image.dandelioncloud.cn/pgy_files/images/2024/04/18/fe4c7aa590e54775bf7eb97a176ad46e.png
[springboot_jdbcUrl is required with driverClassName]: https://blog.csdn.net/shenzhou_yh/article/details/100689804
[bean]: https://image.dandelioncloud.cn/pgy_files/images/2024/04/18/4431a311032d44b0991abdcfeb5f4720.png
[mapper]: https://image.dandelioncloud.cn/pgy_files/images/2024/04/18/fd40000255a14d2abac6b80fabcfbb20.png
[dao]: https://image.dandelioncloud.cn/pgy_files/images/2024/04/18/6dc83936aaa84135ba30d8fa91359ca3.png
[service]: https://image.dandelioncloud.cn/pgy_files/images/2024/04/18/caaad1cb95ae43ad91dfd7233db0e548.png
[SpringBootApplication]: https://www.cnblogs.com/MaxElephant/p/8108140.html
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3NoZW56aG91X3lo_size_16_color_FFFFFF_t_70 1]: https://image.dandelioncloud.cn/pgy_files/images/2024/04/18/3eddbfa20c3f4439b8a83ce66b0a2e86.png