最近项目需要又重新复习了下springboot，关于springboot配置多数据源，做了笔记，分享给有需要的小伙伴们，视频看的动力节点王鹤老师讲的，

动力节点王鹤老师讲解的springboot教程，由浅入深，带你体验Spring Boot的极速开发过程，内容丰富，涵盖了SpringBoot开发的方方面面，并且同步更新到Spring Boot 2.x系列的最新版本。

视频链接：https://www.bilibili.com/video/BV1XQ4y1m7ex

一、目录结构

目录结构

image

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二、依赖包（pom.xml）

<dependencies>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-data-jpa</artifactId>
    </dependency>
    <dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-configuration-processor</artifactId>
        <optional>true</optional>
    </dependency>
    <dependency>
        <groupId>org.projectlombok</groupId>
        <artifactId>lombok</artifactId>
        <version>1.18.2</version>
    </dependency>
</dependencies>

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三、配置文件

server:
  port: 8080
spring:
  datasource:
    first:
      driver-class-name: com.mysql.jdbc.Driver
      jdbc-url: jdbc:mysql://localhost:3306/first?useUnicode=true&characterEncoding=utf8&allowMultiQueries=true
      username: root
      password: root
    second:
      driver-class-name: com.mysql.jdbc.Driver
      jdbc-url: jdbc:mysql://localhost:3306/second?useUnicode=true&characterEncoding=utf8&allowMultiQueries=true
      username: root
      password: root
  jpa:
    hibernate:
      ddl-auto: update
      naming:
        physical-strategy: org.springframework.boot.orm.jpa.hibernate.SpringPhysicalNamingStrategy
        implicit-strategy: org.springframework.boot.orm.jpa.hibernate.SpringImplicitNamingStrategy
    show-sql: true
    database-platform: org.hibernate.dialect.MySQL5InnoDBDialect
    database: mysql

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四、多数据源配置（jpa）

1. DataSourceConfiguration

package com.cetc.config;

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 javax.sql.DataSource;

/**
 * 数据库配置
 */
@Configuration
public class DataSourceConfiguration {

    /**
     *  第一个数据连接，默认优先级最高
     * @return
     */
    @Bean(name = "dataSourceFirst")
    @Primary
    @ConfigurationProperties(prefix = "spring.datasource.first")
    public DataSource dataSourceFirst() {
        //这种方式的配置默认只满足spring的配置方式，如果使用其他数据连接（druid）,需要自己独立获取配置
        return DataSourceBuilder.create().build();
    }

    /**
     * 第二个数据源
     * @return
     */
    @Bean(name = "dataSourceSecond")
    @ConfigurationProperties(prefix = "spring.datasource.second")
    public DataSource dataSourceSecond() {
        return DataSourceBuilder.create().build();
    }
}

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说明：其实这里配置已经完成了，这里就配置了两个数据源了。可以加入对应的JdbcTemplate,这里不做介绍，比较简单

2. JpaFirstConfiguration

package com.cetc.config;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.boot.autoconfigure.domain.EntityScan;
import org.springframework.boot.autoconfigure.orm.jpa.HibernateSettings;
import org.springframework.boot.autoconfigure.orm.jpa.JpaProperties;
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.annotation.EnableTransactionManagement;

import javax.persistence.EntityManager;
import javax.sql.DataSource;

/**
 * 第一个数据源，jpa的相关配置
 */
@Configuration
@EntityScan(basePackages = "com.cetc.domain.first")
//1、实体扫描
//2、实体管理ref
//3、事务管理
@EnableJpaRepositories(
        basePackages = "com.cetc.repository.first",
        entityManagerFactoryRef = "firstEntityManagerFactoryBean",
        transactionManagerRef = "firstTransactionManager")
@EnableTransactionManagement
public class JpaFirstConfiguration {

    //第一个数据源，可以不加Qualifier
    @Autowired
    @Qualifier("dataSourceFirst")
    private DataSource dataSource;

    //jpa其他参数配置
    @Autowired
    private JpaProperties jpaProperties;

    //实体管理工厂builder
    @Autowired
    private EntityManagerFactoryBuilder factoryBuilder;

    /**
     * 配置第一个实体管理工厂的bean
     * @return
     */
    @Bean(name = "firstEntityManagerFactoryBean")
    @Primary
    public LocalContainerEntityManagerFactoryBean entityManagerFactoryBean() {
        return factoryBuilder.dataSource(dataSource)
                //这一行的目的是加入jpa的其他配置参数比如（ddl-auto: update等）
                //当然这个参数配置可以在事务配置的时候也可以
                .properties(jpaProperties.getHibernateProperties(new HibernateSettings()))
                .packages("com.cetc.domain.first")
                .persistenceUnit("firstPersistenceUnit")
                .build();
    }

    /**
     * EntityManager不过解释，用过jpa的应该都了解
     * @return
     */
    @Bean(name = "firstEntityManager")
    @Primary
    public EntityManager entityManager() {
        return entityManagerFactoryBean().getObject().createEntityManager();
    }

    /**
     * jpa事务管理
     * @return
     */
    @Bean(name = "firstTransactionManager")
    @Primary
    public JpaTransactionManager transactionManager() {
        JpaTransactionManager jpaTransactionManager = new JpaTransactionManager();
        jpaTransactionManager.setEntityManagerFactory(entityManagerFactoryBean().getObject());
        return jpaTransactionManager;
    }
}

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3. JpaSecondConfiguration

package com.cetc.config;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.boot.autoconfigure.domain.EntityScan;
import org.springframework.boot.autoconfigure.orm.jpa.HibernateSettings;
import org.springframework.boot.autoconfigure.orm.jpa.JpaProperties;
import org.springframework.boot.orm.jpa.EntityManagerFactoryBuilder;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.data.jpa.repository.config.EnableJpaRepositories;
import org.springframework.orm.jpa.JpaTransactionManager;
import org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean;
import org.springframework.transaction.annotation.EnableTransactionManagement;

import javax.persistence.EntityManager;
import javax.sql.DataSource;

/**
 * 第二个数据源，jpa的相关配置
 */
@Configuration
@EntityScan(basePackages = "com.cetc.domain.second")
//1、实体扫描
//2、实体管理ref
//3、事务管理
@EnableJpaRepositories(
        basePackages = "com.cetc.repository.second",
        entityManagerFactoryRef = "secondEntityManagerFactoryBean",
        transactionManagerRef = "secondTransactionManager")
@EnableTransactionManagement
public class JpaSecondConfiguration {

    //第二个数据源，必须加Qualifier
    @Autowired
    @Qualifier("dataSourceSecond")
    private DataSource dataSource;

    //jpa其他参数配置
    @Autowired
    private JpaProperties jpaProperties;

    //实体管理工厂builder
    @Autowired
    private EntityManagerFactoryBuilder factoryBuilder;

    /**
     * 配置第二个实体管理工厂的bean
     * @return
     */
    @Bean(name = "secondEntityManagerFactoryBean")
    public LocalContainerEntityManagerFactoryBean entityManagerFactoryBean() {
        return factoryBuilder.dataSource(dataSource)
                .properties(jpaProperties.getHibernateProperties(new HibernateSettings()))
                .packages("com.cetc.domain.second")
                .persistenceUnit("secondPersistenceUnit")
                .build();
    }

    /**
     * EntityManager不过解释，用过jpa的应该都了解
     * @return
     */
    @Bean(name = "secondEntityManager")
    public EntityManager entityManager() {
        return entityManagerFactoryBean().getObject().createEntityManager();
    }

    /**
     * jpa事务管理
     * @return
     */
    @Bean(name = "secondTransactionManager")
    public JpaTransactionManager transactionManager() {
        JpaTransactionManager jpaTransactionManager = new JpaTransactionManager();
        jpaTransactionManager.setEntityManagerFactory(entityManagerFactoryBean().getObject());
        return jpaTransactionManager;
    }
}

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