SpringBoot2.x系列教程48--多数据源配置之AOP动态切换数据源

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SpringBoot2.x系列教程48--多数据源配置之AOP动态切换数据源

2022-12-23 15:33:50 来源：51CTO博客

SpringBoot2.x系列教程48--多数据源配置之AOP动态切换数据源

作者：一一哥

在上一节中，我通过分包的方式实现了多数据源的配置，接下来我通过AOP切面的方式，带领大家实现第二种多数据源配置方式，该方式是在前面案例的基础上进行编写的。

一. 实现过程

1. 创建web项目

我们按照之前的经验，创建一个web程序，并将之改造成Spring Boot项目，具体过程略。

(资料图片仅供参考)

2. 添加依赖包

   org.springframework.boot   spring-boot-starter-data-jpa   mysql   mysql-connector-java   com.alibaba   druid   1.1.10

3. 创建application.yml配置文件

在该配置文件中，要进行两个数据库的配置，本案例中我们使用默认的HikariDataSource数据源。

spring:  main:    allow-bean-definition-overriding: true  datasource:    ds1:      url: jdbc:mysql://localhost:3306/db1?characterEncoding=utf-8&useSSL=false&serverTimezone=UTC      username: root      password: syc      driverClassName: com.mysql.jdbc.Driver    ds2:      url: jdbc:mysql://localhost:3306/db4?characterEncoding=utf-8&useSSL=false&serverTimezone=UTC      username: root      password: syc      driverClassName: com.mysql.jdbc.Driver    type: com.zaxxer.hikari.HikariDataSource#    type: com.alibaba.druid.pool.DruidDataSource  jpa:    database: mysql    show-sql: true    hibernate:      ddl-auto: update      naming:        physical-strategy: org.hibernate.boot.model.naming.PhysicalNamingStrategyStandardImpl    database-platform: org.hibernate.dialect.MySQL5Dialect

4. 创建数据库配置类

第一个数据库配置类

package com.yyg.boot.config.properties;import lombok.Data;import org.springframework.boot.context.properties.ConfigurationProperties;import org.springframework.stereotype.Component;/** * @Author 一一哥Sun * @Date Created in 2020/4/3 * @Description db1数据源配置类 */@ConfigurationProperties(prefix = "spring.datasource.ds1")@Component("ds1Properties")@Datapublic class Ds1Properties {    private String url;    private String username;    private String password;    private String driverClassName;}

第2个数据库配置类

package com.yyg.boot.config.properties;import lombok.Data;import org.springframework.boot.context.properties.ConfigurationProperties;import org.springframework.stereotype.Component;/** * @Author 一一哥Sun * @Date Created in 2020/4/3 * @Description db4数据源配置类 */@ConfigurationProperties(prefix = "spring.datasource.ds2")@Component("ds2Properties")@Datapublic class Ds2Properties {    private String url;    private String username;    private String password;    private String driverClassName;}

5. 注册数据源

我们在一个类中注册两个数据源就可以了。

package com.yyg.boot.config;import org.springframework.beans.factory.annotation.Qualifier;import org.springframework.boot.autoconfigure.jdbc.DataSourceProperties;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 javax.sql.DataSource;/** * @Author 一一哥Sun * @Date Created in 2020/4/3 * @Description 数据源的配置类 */@Configurationpublic class DataSourceRegisterConfig {    /**     * 主数据源配置 ds1数据源     */    @Primary    @Bean(name = "ds1Properties")    @ConfigurationProperties(prefix = "spring.datasource.ds1")    public DataSourceProperties ds1DataSourceProperties() {        return new DataSourceProperties();    }    /**     * 主数据源 ds1数据源     */    @Primary    @Bean(name = "ds1DataSource")    public DataSource ds1DataSource(@Qualifier("ds1Properties") DataSourceProperties dataSourceProperties) {        //HikariDataSource","org.apache.tomcat.jdbc.pool.DataSource", "org.apache.commons.dbcp2.BasicDataSource        return dataSourceProperties.initializeDataSourceBuilder().build();    }    /**     * 第二个ds2数据源配置     */    @Bean(name = "ds2Properties")    @ConfigurationProperties(prefix = "spring.datasource.ds2")    public DataSourceProperties ds2DataSourceProperties() {        return new DataSourceProperties();    }    /**     * 第二个ds2数据源     */    @Bean("ds2DataSource")    public DataSource ds2DataSource(@Qualifier("ds2Properties") DataSourceProperties dataSourceProperties) {        return dataSourceProperties.initializeDataSourceBuilder().build();    }}

6. 配置数据源、连接工厂、事务管理器、扫描dao目录

注意合理的使用@Primary注解！

配置第一个数据源管理器

package com.yyg.boot.config;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.beans.factory.annotation.Qualifier;import org.springframework.boot.orm.jpa.EntityManagerFactoryBuilder;import org.springframework.context.annotation.Bean;import org.springframework.context.annotation.Configuration;import org.springframework.context.annotation.Primary;import org.springframework.data.jpa.repository.config.EnableJpaRepositories;import org.springframework.orm.jpa.JpaTransactionManager;import org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean;import org.springframework.transaction.PlatformTransactionManager;import org.springframework.transaction.annotation.EnableTransactionManagement;import javax.sql.DataSource;/** * @Author 一一哥Sun * @Date Created in 2020/4/3 * @Description 配置数据源、连接工厂、事务管理器、dao目录 */@Configuration@EnableTransactionManagement@EnableJpaRepositories(        entityManagerFactoryRef = "managerFactory1", // 配置连接工厂        transactionManagerRef = "transactionManager1", // 配置事物管理器        basePackages = {"com.yyg.boot.dao.db01"} // 设置dao所在位置)public class ManagerFactory01Config {    /**     * 配置数据源,连接第1个数据源     */    @Autowired    @Qualifier("ds1DataSource")    private DataSource ds1DataSource;    @Primary    @Bean(name = "managerFactory1")    public LocalContainerEntityManagerFactoryBean buildEntityManagerFactory1(EntityManagerFactoryBuilder builder) {        return builder                // 设置数据源                .dataSource(ds1DataSource)                //设置实体类所在位置.扫描所有带有 @Entity 注解的类                .packages("com.yyg.boot.entity")                // Spring会将EntityManagerFactory注入到Repository之中.有了 EntityManagerFactory之后,                // Repository就能用它来创建 EntityManager 了,然后 EntityManager 就可以针对数据库执行操作                .persistenceUnit("ds1PersistenceUnit")                .build();    }    /**     * 配置事务管理器     */    @Bean(name = "transactionManager1")    public PlatformTransactionManager transactionManagerDatabase1(EntityManagerFactoryBuilder builder) {        return new JpaTransactionManager(buildEntityManagerFactory1(builder).getObject());    }}

配置第2个数据源管理器

package com.yyg.boot.config;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.beans.factory.annotation.Qualifier;import org.springframework.boot.orm.jpa.EntityManagerFactoryBuilder;import org.springframework.context.annotation.Bean;import org.springframework.context.annotation.Configuration;import org.springframework.context.annotation.Primary;import org.springframework.data.jpa.repository.config.EnableJpaRepositories;import org.springframework.orm.jpa.JpaTransactionManager;import org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean;import org.springframework.transaction.PlatformTransactionManager;import org.springframework.transaction.annotation.EnableTransactionManagement;import javax.sql.DataSource;/** * @Author 一一哥Sun * @Date Created in 2020/4/3 * @Description 配置数据源、连接工厂、事务管理器、dao目录 */@Configuration@EnableTransactionManagement@EnableJpaRepositories(        entityManagerFactoryRef = "managerFactory2", // 配置连接工厂        transactionManagerRef = "transactionManager2", // 配置事物管理器        basePackages = {"com.yyg.boot.dao.db02"} // 设置dao所在位置)public class ManagerFactory02Config {    /**     * 配置数据源,连接第2个数据源     */    @Autowired    @Qualifier("ds2DataSource")    private DataSource ds2DataSource;    @Bean(name = "managerFactory2")    public LocalContainerEntityManagerFactoryBean buildEntityManagerFactory2(EntityManagerFactoryBuilder builder) {        return builder                // 设置数据源                .dataSource(ds2DataSource)                //设置实体类所在位置.扫描所有带有 @Entity 注解的类                .packages("com.yyg.boot.entity")                // Spring会将EntityManagerFactory注入到Repository之中.有了 EntityManagerFactory之后,                // Repository就能用它来创建 EntityManager 了,然后 EntityManager 就可以针对数据库执行操作                .persistenceUnit("ds2PersistenceUnit")                .build();    }    /**     * 配置事务管理器     */    @Bean(name = "transactionManager2")    public PlatformTransactionManager transactionManagerDatabase1(EntityManagerFactoryBuilder builder) {        return new JpaTransactionManager(buildEntityManagerFactory2(builder).getObject());    }}

7. 创建数据源类型

利用ThreadLocal确保线程安全性，每个线程之间不会相互影响。

package com.yyg.boot.datasource;import lombok.extern.slf4j.Slf4j;/** * @Author 一一哥Sun * @Date Created in 2020/4/7 * @Description 数据源类型 */@Slf4jpublic class DataSourceType {    public enum SourceType {        /**         * 用户数据源         */        DS_USER,        /**         * 商品数据源         */        DS_SHOP    }    /**     * 使用ThreadLocal保证线程安全     */    private static final ThreadLocal TYPES = new ThreadLocal<>();    /**     * 往当前线程里设置数据源类型     */    public static void setDataSourceType(SourceType dataSourceType) {        if (dataSourceType == null) {            throw new NullPointerException();        }        log.warn("[设置当前数据源为]：" + dataSourceType);        TYPES.set(dataSourceType);    }    /**     * 获取数据源类型     */    public static SourceType getDataSourceType() {        SourceType dataSourceType = TYPES.get() == null ? SourceType.DS_USER : TYPES.get();        log.warn("[当前数据源的类型为]：" + dataSourceType);        return dataSourceType;    }    /**     * 清空数据类型     */    public static void removeDataSourceType() {        TYPES.remove();    }}

8. 定义动态数据源

定义一个动态数据源,继承AbstractRoutingDataSource 抽象类，并重写determineCurrentLookupKey（）方法。

AbstractRoutingDataSource这个类是实现多数据源的关键，作用是动态切换数据源。在该类中有一个targetDataSources集合，该集合是AbstractRoutingDataSource的一个map类型的属性，其中key表示每个数据源的名字，value为每个数据源。然后根据determineCurrentLookupKey()这个方法获取当前数据源在map中的key值，然后determineTargetDataSource（）方法中动态获取当前数据源，如果当前数据源不存且默认数据源也不存在时就会抛出异常。

package com.yyg.boot.datasource;import org.springframework.jdbc.datasource.lookup.AbstractRoutingDataSource;/** * @Author 一一哥Sun * @Date Created in 2020/4/7 * @Description 动态切换数据源 */public class DynamicDataSource extends AbstractRoutingDataSource {    @Override    protected Object determineCurrentLookupKey() {        return DataSourceType.getDataSourceType();    }}

9. 配置多个数据源

package com.yyg.boot.datasource;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;import java.util.HashMap;import java.util.Map;/** * @Author 一一哥Sun * @Date Created in 2020/4/7 * @Description 多数据源配置 */@Configurationpublic class DynamicDataSourceConfig {    @Bean(name = "dynamicDataSource")    public DynamicDataSource dynamicDataSource(@Qualifier("ds1DataSource") DataSource ds1DataSource,                                        @Qualifier("ds2DataSource") DataSource ds2DataSource) {        Map targetDataSource = new HashMap<>();        targetDataSource.put(DataSourceType.SourceType.DS_SHOP, ds1DataSource);        targetDataSource.put(DataSourceType.SourceType.DS_USER, ds2DataSource);        DynamicDataSource dataSource = new DynamicDataSource();        dataSource.setTargetDataSources(targetDataSource);        dataSource.setDefaultTargetDataSource(ds2DataSource);        return dataSource;    }}

10. 定义AOP切面

package com.yyg.boot.datasource;import lombok.extern.slf4j.Slf4j;import org.aspectj.lang.annotation.Aspect;import org.aspectj.lang.annotation.Before;import org.springframework.stereotype.Component;/** * @Author 一一哥Sun * @Date Created in 2020/4/7 * @Description Description */@Aspect@Component@Slf4jpublic class DataSourceAop {    @Before("execution(* com.yyg.boot.service.impl.GoodsServiceImpl.*(..))")    public void setDataSource01() {        log.warn("db01商品数据源");        DataSourceType.setDataSourceType(DataSourceType.SourceType.DS_SHOP);    }    @Before("execution(* com.yyg.boot.service.impl.UserServiceImpl.*(..))")    public void setDataSource02() {        log.warn("db02用户数据源");        DataSourceType.setDataSourceType(DataSourceType.SourceType.DS_USER);    }}

11. 创建Entity实体类

Goods商品类

package com.yyg.boot.entity;import lombok.Data;import javax.persistence.*;/** * @Author 一一哥Sun * @Date Created in 2020/4/3 * @Description db1中的商品表 */@Entity@Table(name = "goods")@Datapublic class Goods {    @Id    @GeneratedValue(strategy=GenerationType.IDENTITY)    private Long id;    private String name;}

User用户类

package com.yyg.boot.entity;import lombok.Data;import javax.persistence.*;/** * @Author 一一哥Sun * @Date Created in 2020/4/3 * @Description db4中的用户表 */@Entity@Table(name = "user")@Datapublic class User {    @Id    @GeneratedValue(strategy=GenerationType.IDENTITY)    private Long id;    private String username;    private String birthday;    private String sex;    private String address;}

12. 创建Dao层代码

GoodsRepository类

package com.yyg.boot.dao.db01;import com.yyg.boot.entity.Goods;import com.yyg.boot.entity.User;import org.springframework.data.jpa.repository.JpaRepository;import org.springframework.data.jpa.repository.JpaSpecificationExecutor;import org.springframework.stereotype.Repository;/** * @Author 一一哥Sun * @Date Created in 2020/4/3 * @Description Description */@Repositorypublic interface GoodsRepository extends JpaRepository,JpaSpecificationExecutor {}

UserRepository类

package com.yyg.boot.dao.db02;import com.yyg.boot.entity.User;import org.springframework.data.jpa.repository.JpaRepository;import org.springframework.data.jpa.repository.JpaSpecificationExecutor;import org.springframework.stereotype.Repository;/** * @Author 一一哥Sun * @Date Created in 2020/4/3 * @Description Description */@Repositorypublic interface UserRepository extends JpaRepository,JpaSpecificationExecutor {}

13. 创建Service代码

UserServiceImpl实现类

package com.yyg.boot.service.impl;import com.yyg.boot.dao.db02.UserRepository;import com.yyg.boot.entity.User;import com.yyg.boot.service.UserService;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.stereotype.Service;import java.util.List;/** * @Author 一一哥Sun * @Date Created in 2020/4/7 * @Description Description */@Servicepublic class UserServiceImpl implements UserService {    @Autowired    private UserRepository userRepository;    @Override    public List findAll() {        return userRepository.findAll();    }}

GoodsServiceImpl实现类

package com.yyg.boot.service.impl;import com.yyg.boot.dao.db01.GoodsRepository;import com.yyg.boot.dao.db02.UserRepository;import com.yyg.boot.entity.Goods;import com.yyg.boot.entity.User;import com.yyg.boot.service.GoodsService;import com.yyg.boot.service.UserService;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.stereotype.Service;import java.util.List;/** * @Author 一一哥Sun * @Date Created in 2020/4/7 * @Description Description */@Servicepublic class GoodsServiceImpl implements GoodsService {    @Autowired    private GoodsRepository goodsRepository;    @Override    public List findAll() {        return goodsRepository.findAll();    }}

14. 创建Controller接口

package com.yyg.boot.web;import com.yyg.boot.entity.Goods;import com.yyg.boot.entity.User;import com.yyg.boot.service.GoodsService;import com.yyg.boot.service.UserService;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.web.bind.annotation.GetMapping;import org.springframework.web.bind.annotation.RestController;import java.util.List;/** * @Author 一一哥Sun * @Date Created in 2020/4/3 * @Description Description */@RestControllerpublic class GoodsController {    @Autowired    private UserService userService;    @Autowired    private GoodsService goodsService;    @GetMapping(value = "/users")    public List users() {        return userService.findAll();    }    @GetMapping(value = "/goods")    public List goods() {        return goodsService.findAll();    }}

15. 创建入口类

package com.yyg.boot;import org.springframework.boot.SpringApplication;import org.springframework.boot.autoconfigure.SpringBootApplication;/** * @Author 一一哥Sun * @Date Created in 2020/4/3 * @Description Description */@SpringBootApplicationpublic class DataSourceApplication {    public static void main(String[] args){        SpringApplication.run(DataSourceApplication.class,args);    }}