SpringBoot搭建多数据源的实现方法

2024-04-02 19:55

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首先我们建立两个数据库（可以不在同一台电脑上）:

multiple_order：


DROP DATABASE IF EXISTS `multiple_order`;
CREATE DATABASE `multiple_order`;
USE `multiple_order`;

CREATE TABLE `order` (
    `order_id` BIGINT UNSIGNED PRIMARY KEY AUTO_INCREMENT COMMENT '订单id',
    `user_id` BIGINT UNSIGNED NOT NULL COMMENT '用户id',
    `cost` DECIMAL(13, 2) COMMENT '订单费用'
) COMMENT '订单表';

multiple_user：


DROP DATABASE IF EXISTS `multiple_user`;
CREATE DATABASE `multiple_user`;
USE `multiple_user`;

CREATE TABLE `user` (
    `user_id` BIGINT UNSIGNED PRIMARY KEY AUTO_INCREMENT COMMENT '用户id',
    `username` VARCHAR(50) NOT NULL COMMENT '用户名',
    `age` TINYINT UNSIGNED COMMENT '年龄'
) COMMENT '用户表';

然后创建一个maven项目，其中 pom.xml 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 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <!-- SpringBoot的夫项目 -->
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.3.9.RELEASE</version>
    </parent>

    <groupId>love.xiaohh.datasource</groupId>
    <artifactId>multiple-datasources</artifactId>
    <version>1.0-SNAPSHOT</version>

    <properties>
        <maven.compiler.source>8</maven.compiler.source>
        <maven.compiler.target>8</maven.compiler.target>
    </properties>

    <dependencies>
        <!-- SpringMVC 相关的依赖 -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <!-- Spring 健康检测模块 -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-actuator</artifactId>
        </dependency>

        <!-- mybatis 相关依赖 -->
        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>2.2.0</version>
        </dependency>

        <!-- MySQL 驱动 -->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
        </dependency>

        <!-- json 工具类 -->
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>fastjson</artifactId>
            <version>1.2.78</version>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <!-- 制作一个可运行的 jar 包需要的插件 -->
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

</project>

在 application.yml 中需要配置两个数据源：


spring:
  datasource:
    # 用户模块数据库配置
    user:
      driver-class-name: com.mysql.cj.jdbc.Driver
      jdbc-url: jdbc:mysql://127.0.0.1:3306/multiple_user?useUnicode=true&characterEncoding=utf8&zeroDateTimeBehavior=convertToNull&useSSL=true&serverTimezone=GMT%2B8
      username: root
      password: xiaohh
    # 订单模块数据库配置
    order:
      driver-class-name: com.mysql.cj.jdbc.Driver
      jdbc-url: jdbc:mysql://127.0.0.1:3306/multiple_order?useUnicode=true&characterEncoding=utf8&zeroDateTimeBehavior=convertToNull&useSSL=true&serverTimezone=GMT%2B8
      username: root
      password: xiaohh

mybatis:
  # Mapper 的目录
  mapper-locations: classpath:mapper*Mapper.xml

然后我们定义一个配置类 DataSourseConfig 用于配置多数据源，首先是申明数据源，按照 application.yml 当中的配置定义两个数据源，注意当中的DataSource 是 javax.sql.DataSource：



@Primary // 需要一个默认配置的数据源
@Bean("user")
@ConfigurationProperties(prefix = "spring.datasource.user") // 在yml中配置数据源的前缀
public DataSource user() {
    return DataSourceBuilder.create().build();
}


@Bean("order")
@ConfigurationProperties(prefix = "spring.datasource.order") // 在yml中配置数据源的前缀
public DataSource order() {
    return DataSourceBuilder.create().build();
}

然后创建 SqlSessionFactory ：



@Primary // 配置一个这个类型默认的 bean
@Bean("userSqlSessionFactory")
public SqlSessionFactory userSqlSessionFactory(@Qualifier("user") DataSource user) throws Exception {
    // 创建bean
    SqlSessionFactoryBean factory = new SqlSessionFactoryBean();
    // 设置数据源
    factory.setDataSource(user);
    // 设置 mapper 文件的扫描
    factory.setMapperLocations(new PathMatchingResourcePatternResolver().getResources("classpath:mapper/user
@Bean("orderSqlSessionFactory")
public SqlSessionFactory orderSqlSessionFactory(@Qualifier("order") DataSource order) throws Exception {
    // 创建bean
    SqlSessionFactoryBean factory = new SqlSessionFactoryBean();
    // 设置数据源
    factory.setDataSource(order);
    // 设置 mapper 文件的扫描
    factory.setMapperLocations(new PathMatchingResourcePatternResolver().getResources("classpath:mapper/order
@Primary // 设置这个类型默认的 bean
@Bean("userSqlSessionTemplate")
public SqlSessionTemplate userSqlSessionTemplate(@Qualifier("userSqlSessionFactory") SqlSessionFactory userSqlSessionFactory) {
    return new SqlSessionTemplate(userSqlSessionFactory);
}


@Bean("orderSqlSessionTemplate")
public SqlSessionTemplate orderSqlSessionTemplate(@Qualifier("orderSqlSessionFactory") SqlSessionFactory orderSqlSessionFactory) {
    return new SqlSessionTemplate(orderSqlSessionFactory);
}

最后别忘了在配置类上加上一个注解，用于声明哪些Mapper文件用哪些注解：


@Configuration
@MapperScans({
        // basePackages 是mapper的包路径，sqlSessionTemplateRef 是指定我们创建的 SqlSessionTemplate
        @MapperScan(basePackages = "love.xiaohh.datasource.mapper.user", sqlSessionTemplateRef = "userSqlSessionTemplate"),
        @MapperScan(basePackages = "love.xiaohh.datasource.mapper.order", sqlSessionTemplateRef = "orderSqlSessionTemplate")
})

完整的 DataSourceConfig 类的代码：


package love.xiaohh.datasource.config;

import org.apache.ibatis.session.SqlSessionFactory;
import org.mybatis.spring.SqlSessionFactoryBean;
import org.mybatis.spring.SqlSessionTemplate;
import org.mybatis.spring.annotation.MapperScan;
import org.mybatis.spring.annotation.MapperScans;
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;


@Configuration
@MapperScans({
        // basePackages 是mapper的包路径，sqlSessionTemplateRef 是指定我们创建的 SqlSessionTemplate
        @MapperScan(basePackages = "love.xiaohh.datasource.mapper.user", sqlSessionTemplateRef = "userSqlSessionTemplate"),
        @MapperScan(basePackages = "love.xiaohh.datasource.mapper.order", sqlSessionTemplateRef = "orderSqlSessionTemplate")
})
public class DataSourceConfig {

    
    @Primary // 需要一个默认配置的数据源
    @Bean("user")
    @ConfigurationProperties(prefix = "spring.datasource.user") // 在yml中配置数据源的前缀
    public DataSource user() {
        return DataSourceBuilder.create().build();
    }

    
    @Bean("order")
    @ConfigurationProperties(prefix = "spring.datasource.order") // 在yml中配置数据源的前缀
    public DataSource order() {
        return DataSourceBuilder.create().build();
    }

    
    @Primary // 配置一个这个类型默认的 bean
    @Bean("userSqlSessionFactory")
    public SqlSessionFactory userSqlSessionFactory(@Qualifier("user") DataSource user) throws Exception {
        // 创建bean
        SqlSessionFactoryBean factory = new SqlSessionFactoryBean();
        // 设置数据源
        factory.setDataSource(user);
        // 设置 mapper 文件的扫描
        factory.setMapperLocations(new PathMatchingResourcePatternResolver().getResources("classpath:mapper/user
    @Bean("orderSqlSessionFactory")
    public SqlSessionFactory orderSqlSessionFactory(@Qualifier("order") DataSource order) throws Exception {
        // 创建bean
        SqlSessionFactoryBean factory = new SqlSessionFactoryBean();
        // 设置数据源
        factory.setDataSource(order);
        // 设置 mapper 文件的扫描
        factory.setMapperLocations(new PathMatchingResourcePatternResolver().getResources("classpath:mapper/order
    @Primary // 设置这个类型默认的 bean
    @Bean("userSqlSessionTemplate")
    public SqlSessionTemplate userSqlSessionTemplate(@Qualifier("userSqlSessionFactory") SqlSessionFactory userSqlSessionFactory) {
        return new SqlSessionTemplate(userSqlSessionFactory);
    }

    
    @Bean("orderSqlSessionTemplate")
    public SqlSessionTemplate orderSqlSessionTemplate(@Qualifier("orderSqlSessionFactory") SqlSessionFactory orderSqlSessionFactory) {
        return new SqlSessionTemplate(orderSqlSessionFactory);
    }
}

然后按照注解上面定义的包创建两个 Mapper 接口

OrderMapper：


package love.xiaohh.datasource.mapper.order;

import love.xiaohh.datasource.entities.order.Order;
import org.apache.ibatis.annotations.Mapper;

import java.util.List;


@Mapper
public interface OrderMapper {

    
    int insertOrder(Order order);

    
    List<Order> selectOrder(Order order);
}

UserMapper：


package love.xiaohh.datasource.mapper.user;

import love.xiaohh.datasource.entities.user.User;
import org.apache.ibatis.annotations.Mapper;

import java.util.List;


@Mapper
public interface UserMapper {

    
    int insertUser(User user);

    
    List<User> selectUser(User user);
}

之后我会将代码提交到 gitee，所以 Mapper.xml、Controller、Service 代码在此处省略，然后我们新增几条用户数据：

在这里插入图片描述