springboot 集成多數據源學習片1——使用JPA實現

1.引入JpA

<dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-jpa</artifactId>
        </dependency>

2.配置數據源

package com.example.jpa.demojpa;

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 javax.sql.DataSource;

@Configuration
public class DataSourceConfig {


    @Bean(name = "primaryDataSource")
    @Qualifier("primaryDataSource")
    @Primary
    @ConfigurationProperties(prefix = "spring.datasource.primary")
    public DataSource primaryDataSource() {
        System.out.println("primary db built");
        return DataSourceBuilder.create().build();
    }

    @Bean(name = "secondaryDataSource")
    @Qualifier("secondaryDataSource")
    @ConfigurationProperties(prefix = "spring.datasource.secondary")
    public DataSource secondaryDataSource() {
        System.out.println("secondary db built");
        return DataSourceBuilder.create().build();
    }

}

package com.example.jpa.demojpa;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.boot.autoconfigure.orm.jpa.HibernateProperties;
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;

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

@Configuration
@EnableTransactionManagement
@EnableJpaRepositories(
        entityManagerFactoryRef = "masterEntityManagerFactory",
        transactionManagerRef = "masterTransactionManager",
        basePackages = {"jpa1"})//jpa所在包

public class MasterConfig {
    @Autowired
    private HibernateProperties hibernateProperties;
    @Resource
    @Qualifier("primaryDataSource")
    private DataSource masterDataSource;

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

    @Resource
    private JpaProperties jpaProperties;

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

    /**
     * 設置實體類所在位置
     */
    @Primary
    @Bean(name = "masterEntityManagerFactory")
    public LocalContainerEntityManagerFactoryBean masterEntityManagerFactory(EntityManagerFactoryBuilder builder) {

        Map<String, Object> properties = hibernateProperties.determineHibernateProperties(
                jpaProperties.getProperties(), new HibernateSettings());
        return builder
                .dataSource(masterDataSource)
                .packages("com.example.jpa.demojpa")
                .persistenceUnit("masterPersistenceUnit")
                .properties(properties)
                .build();
    }

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

package com.example.jpa.demojpa;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.boot.autoconfigure.orm.jpa.HibernateProperties;
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.annotation.Resource;
import javax.persistence.EntityManager;
import javax.sql.DataSource;
import java.util.Map;


@Configuration
@EnableTransactionManagement
@EnableJpaRepositories(
        entityManagerFactoryRef = "slaveEntityManagerFactory",
        transactionManagerRef = "slaveTransactionManager",
        basePackages = {"jpa2"})//repository的目錄
public class SlaveConfig {

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

    @Autowired
    private HibernateProperties hibernateProperties;

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

    @Resource
    private JpaProperties jpaProperties;


    @Bean(name = "slaveEntityManagerFactory")
    public LocalContainerEntityManagerFactoryBean slaveEntityManagerFactory(EntityManagerFactoryBuilder builder) {

        Map<String, Object> properties = hibernateProperties.determineHibernateProperties(
                jpaProperties.getProperties(), new HibernateSettings());
        return builder
                .dataSource(slaveDataSource)
                .packages("com.example.jpa.demojpa")//實體類的目錄
                .persistenceUnit("slavePersistenceUnit")
                .properties(properties)
                .build();
    }

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

}

spring.datasource.primary.jdbc-url=jdbc:mysql://xxx:3306/testmydb
spring.datasource.primary.username=root
spring.datasource.primary.driverClassName=com.mysql.cj.jdbc.Driver
spring.datasource.primary.password=


spring.datasource.secondary.jdbc-url=jdbc:mysql://xxx:3306/demo
spring.datasource.secondary.username=root
spring.datasource.secondary.driverClassName=com.mysql.cj.jdbc.Driver
spring.datasource.secondary.password=

@Repository
public interface UserMapper2 extends JpaRepository<User2, Integer> {
}