SpringBoot2.0 配置多數據源

一、簡述

配置多數據源意思就是在一個項目中使用多個數據庫，在項目使用中可以不用手動切換數據庫來實現不同數據庫的數據獲取和更新。

源碼地址： https://github.com/hanguilin/boot-security

項目環境： SpringBoot 2.1.9、Spring Data Jpa

項目文件夾：

二、配置

application.properties

• spring.datasource.primary.driver-class-name  數據庫驅動包

• spring.datasource.primary.jdbc-url 數據庫連接

• spring.datasource.primary.username 用戶名

• spring.datasource.primary.password 密碼

數據庫配置別名可自定義，此處一級庫為primmary。二級數據庫配置同上，別名為secondary。

hikara為數據庫連接池的配置，同類產品還有druid。

server.port=8080

##########一級數據庫配置##########
spring.datasource.primary.driver-class-name=com.mysql.jdbc.Driver
spring.datasource.primary.jdbc-url=jdbc:mysql://localhost:3306/primary_db?autoReconnect=true&useUnicode=true&useSSL=false
spring.datasource.primary.username=root
spring.datasource.primary.password=****
#最大連接數
spring.datasource.primary.hikari.maximum-pool-size=20
#連接超時毫秒
spring.datasource.primary.hikari.connection-timeout=60000
#空閑的連接的生命時長毫秒
spring.datasource.primary.hikari.idle-timeout=60000
#連接的生命時長毫秒
spring.datasource.primary.hikari.max-lifetime=60000
#驗證連接有效性毫秒
spring.datasource.primary.hikari.validation-timeout=3000
#登錄超時毫秒
spring.datasource.primary.hikari.login-timeout=5
##########一級數據庫配置##########

##########二級數據庫配置##########
spring.datasource.secondary.driver-class-name=com.mysql.jdbc.Driver
spring.datasource.secondary.jdbc-url=jdbc:mysql://localhost:3306/secondary_db?autoReconnect=true&useUnicode=true
spring.datasource.secondary.username=root
spring.datasource.secondary.password=****
#最大連接數
spring.datasource.secondary.hikari.maximum-pool-size=20
#連接超時毫秒
spring.datasource.secondary.hikari.connection-timeout=60000
#空閑的連接的生命時長毫秒
spring.datasource.secondary.hikari.idle-timeout=60000
#連接的生命時長毫秒
spring.datasource.secondary.hikari.max-lifetime=60000
#驗證連接有效性毫秒
spring.datasource.secondary.hikari.validation-timeout=3000
#登錄超時毫秒
spring.datasource.secondary.hikari.login-timeout=5
##########二級數據庫配置##########

##########hibernate配置##########
spring.jpa.hibernate.ddl-auto=create-drop
spring.jpa.show-sql=true
spring.jpa.properties.hibernate.hbm2ddl.auto=update
spring.jpa.properties.hibernate.dialect=org.hibernate.dialect.MySQL5InnoDBDialect
##########hibernate配置##########

DataSourcesConfig.java

• @Bean(name = "primaryDataSource")

將該返回對象交由Spring管理，bean名稱為primaryDataSource。

• @Qualifier("primaryDataSource")

根據名稱將bean注入到對象。

• @Primary

自動裝配時當出現多個Bean候選者時，被注解為@Primary的Bean將作為首選者，否則將拋出異常。

• @ConfigurationProperties(prefix="spring.datasource.primary")

將前綴為spring.datasource.primary的配置注入到對應名稱的屬性字段中。

此類作用為生成兩級DataSource，交由Spring管理，方便后續從Spring中調用。

package com.spring.security.config.datasource;

import javax.sql.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 com.zaxxer.hikari.HikariDataSource;

@Configuration
public class DataSourcesConfig {

    @Bean(name = "primaryDataSource")
    @Qualifier("primaryDataSource")
    @Primary
    @ConfigurationProperties(prefix="spring.datasource.primary")
    public DataSource primaryDataSource() {
        return DataSourceBuilder.create()
        		.type(HikariDataSource.class)
                .build();
    }

    @Bean(name = "secondaryDataSource")
    @Qualifier("secondaryDataSource")
    @ConfigurationProperties(prefix="spring.datasource.secondary")
    public DataSource secondaryDataSource() {
    	return DataSourceBuilder.create()
        		.type(HikariDataSource.class)
                .build();
    }
}

PrimaryConfig.java

• @Configuration

在Spring中注冊成bean

• @EnableTransactionManagement

開啟事務管理

@EnableJpaRepositories(
        entityManagerFactoryRef="entityManagerFactoryPrimary",
        transactionManagerRef="transactionManagerPrimary",
        basePackages= { "com.spring.security.dao.primary" })

• @EnableJpaRepositories

注解用於Srping JPA的代碼配置，用於取代xml形式的配置文件

• entityManagerFactoryRef

實體管理工廠，下文代碼中配置基礎包為com.spring.security.entity.primary

• transactionManagerRef

事務管理

• basePackages

持久層基礎包掃描，此處配置為com.spring.security.dao.primary

上述兩個包的配置，意為一級數據庫的實體和dao蹭接口分別所處的位置。當jpa進行實體映射時，對應包下面的實體會映射到不通的數據庫。dao層接口也會隨之切換。

package com.spring.security.config.datasource;

import java.util.Map;

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

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Qualifier;
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.PlatformTransactionManager;
import org.springframework.transaction.annotation.EnableTransactionManagement;

@Configuration
@EnableTransactionManagement
@EnableJpaRepositories(
        entityManagerFactoryRef="entityManagerFactoryPrimary",
        transactionManagerRef="transactionManagerPrimary",
        basePackages= { "com.spring.security.dao.primary" }) //設置Repository所在位置
public class PrimaryConfig {

    @Autowired 
    @Qualifier("primaryDataSource")
    private DataSource primaryDataSource;

    @Autowired(required=false)
    private JpaProperties jpaProperties;

    @Primary
    @Bean(name = "entityManagerPrimary")
    public EntityManager entityManager(EntityManagerFactoryBuilder builder) {
        return entityManagerFactoryPrimary(builder).getObject().createEntityManager();
    }

    @Primary
    @Bean(name = "entityManagerFactoryPrimary")
    public LocalContainerEntityManagerFactoryBean entityManagerFactoryPrimary (EntityManagerFactoryBuilder builder) {
        return builder
                .dataSource(primaryDataSource)
                .properties(getVendorProperties())
                .packages("com.spring.security.entity.primary") //設置實體類所在位置
                .persistenceUnit("primaryPersistenceUnit")
                .build();
    }

    private Map<String, Object> getVendorProperties() {
        return jpaProperties.getHibernateProperties(new HibernateSettings());
    }

    @Primary
    @Bean(name = "transactionManagerPrimary")
    public PlatformTransactionManager transactionManagerPrimary(EntityManagerFactoryBuilder builder) {
        return new JpaTransactionManager(entityManagerFactoryPrimary(builder).getObject());
    }

}

SecondaryConfig.java

package com.spring.security.config.datasource;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Qualifier;
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.PlatformTransactionManager;
import org.springframework.transaction.annotation.EnableTransactionManagement;

import javax.persistence.EntityManager;
import javax.sql.DataSource;
import java.util.Map;

@Configuration
@EnableTransactionManagement
@EnableJpaRepositories(
        entityManagerFactoryRef="entityManagerFactorySecondary",
        transactionManagerRef="transactionManagerSecondary",
        basePackages= { "com.spring.security.dao.secondary" }) //設置Repository所在位置
public class SecondaryConfig {

    @Autowired
    private JpaProperties jpaProperties;

    @Autowired 
    @Qualifier("secondaryDataSource")
    private DataSource secondaryDataSource;

    @Bean(name = "entityManagerSecondary")
    public EntityManager entityManager(EntityManagerFactoryBuilder builder) {
        return entityManagerFactorySecondary(builder).getObject().createEntityManager();
    }

    @Bean(name = "entityManagerFactorySecondary")
    public LocalContainerEntityManagerFactoryBean entityManagerFactorySecondary (EntityManagerFactoryBuilder builder) {
        return builder
                .dataSource(secondaryDataSource)
                .properties(getVendorProperties())
                .packages("com.spring.security.entity.secondary") //設置實體類所在位置
                .persistenceUnit("secondaryPersistenceUnit")
                .build();
    }

    private Map<String, Object> getVendorProperties() {
        return jpaProperties.getHibernateProperties(new HibernateSettings());
    }

    @Bean(name = "transactionManagerSecondary")
    PlatformTransactionManager transactionManagerSecondary(EntityManagerFactoryBuilder builder) {
        return new JpaTransactionManager(entityManagerFactorySecondary(builder).getObject());
    }

}

如果需要擴展更多數據庫，可以根據上述配置自行增加。