jpa多数据源Hibernate配置生成表不生效

时间:2022-05-23 天涯泪小武人气:1

jpa配置多数据源教程很多，在Springboot2之后有一些变化，来看一下。

application.yml如下

spring:
  application:
    name: t3cc
  datasource:
    primary:
        jdbc-url: jdbc:mysql://${MYSQL_HOST:localhost}:${MYSQL_PORT:3306}/${DB_NAME:anbang}?useUnicode=true&characterEncoding=UTF8&serverTimezone=Hongkong
        username: root
        password: root
    secondary:
        jdbc-url: jdbc:mysql://${MYSQL_HOST:localhost}:${MYSQL_PORT:3306}/${DB_NAME:anbang1}?useUnicode=true&characterEncoding=UTF8&serverTimezone=Hongkong
        username: root
        password: root
  jpa:
    database: mysql
    database-platform: org.hibernate.dialect.MySQL5InnoDBDialect  #不加这句则默认为myisam引擎
    hibernate:
      ddl-auto: update
      naming:
        physical-strategy: org.springframework.boot.orm.jpa.hibernate.SpringPhysicalNamingStrategy
    open-in-view: true
    properties:
        enable_lazy_load_no_trans: true
    show-sql: true
  cloud:
    nacos:
      discovery:
        server-addr: ${NACOS_SERVER:localhost:8848}
###############################---log---##############################
logging:
  file: ./logback.log

yml里配置了两个数据源，和一些jpa和Hibernate的配置。

下面是DataSource的配置

/**
 * @author wuweifeng wrote on 2019/3/5.
 */
@Configuration
public class DataSourceConfig { 
    @Primary
    @Bean(name = "primaryDataSource")
    @ConfigurationProperties(prefix = "spring.datasource.primary")
    public DataSource dataSourceOrder() {
        return DataSourceBuilder.create().build();
    }
 
    @Bean(name = "secondaryDataSource")
    @ConfigurationProperties(prefix = "spring.datasource.secondary")
    public DataSource dataSourceAuth() {
        return DataSourceBuilder.create().build();
    } 
}

下面是第一个数据源的配置

package com.mm.dmp.t3cc.config; 
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;
 
/**
 * @author wuweifeng wrote on 2019/3/5.
 */
@Configuration
@EnableTransactionManagement
@EnableJpaRepositories(
        entityManagerFactoryRef = "entityManagerFactoryPrimary",
        transactionManagerRef = "transactionManagerPrimary",
        basePackages = {"com.mm.dmp.t3cc.core.repository.one"})
public class OneConfig {
 
    @Resource
    @Qualifier("primaryDataSource")
    private DataSource primaryDataSource;
 
    @Primary
    @Bean(name = "entityManagerPrimary")
    public EntityManager entityManager(EntityManagerFactoryBuilder builder) {
        return entityManagerFactoryPrimary(builder).getObject().createEntityManager();
    }
 
    @Resource
    private JpaProperties jpaProperties;
 
    @Resource
    private HibernateProperties properties;
 
    /**
     * 设置实体类所在位置
     */
    @Primary
    @Bean(name = "entityManagerFactoryPrimary")
    public LocalContainerEntityManagerFactoryBean entityManagerFactoryPrimary(EntityManagerFactoryBuilder builder) { 
        LocalContainerEntityManagerFactoryBean entityManagerFactory = builder
                .dataSource(primaryDataSource)
                //.packages(classes)
                //设置实体类所在位置
                .packages("com.mm.dmp.t3cc.core.entity.one")
                .persistenceUnit("primaryPersistenceUnit")
                //.properties(jpaProperties.getProperties())
                .properties(properties.determineHibernateProperties(jpaProperties.getProperties(), new HibernateSettings()))
                .build();
        return entityManagerFactory;
    }
 
    @Primary
    @Bean(name = "transactionManagerPrimary")
    public PlatformTransactionManager transactionManagerPrimary(EntityManagerFactoryBuilder builder) {
        return new JpaTransactionManager(entityManagerFactoryPrimary(builder).getObject());
    } 
}

这里会和别人的配置不一样，主要区别在于HibernateProperties。别人的在第61行，我注释掉的那行，会直接使用jpaProperties.getProperties()。当你这样写之后，会发现yml里配置的Hibernate的update自动生成表，和命名方式并没有生效。

原因我们可以看一下。

这里就是jpaProperties.getProperties()的地方，如果打断点可以看到，只有箭头这一个配置被加载进去了。上面的Hibernate的ddl和naming并没有进去。

来看一下HibernateProperties

这里才是真正让自动建表生效的地方，然而并没有加载进去。那么就需要我们手工来添加了。

这里面有个determineHibernateProperties方法，就是来组合jpaProperties和HibernateProperties的地方。我们应该使用这个方法来组合整个配置的map对象。

也就是在OneConfig类中，把两个Properties都定义出来，然后组合一下，就是箭头的地方。在debug时，就可以看到Hibernate的配置也都加载进来了。

OK，以上就是动态数据源配置Hibernate自动建表不生效的原因。

下面是第二个数据源的配置

package com.mm.dmp.t3cc.config; 
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;
 
/**
 * @author wuweifeng wrote on 2019/3/5.
 */
@Configuration
@EnableTransactionManagement
@EnableJpaRepositories(
        entityManagerFactoryRef = "entityManagerFactorySecondary",
        transactionManagerRef = "transactionManagerSecondary",
        basePackages = {"com.mm.dmp.t3cc.core.repository.two"}) //设置Repository所在位置
public class TwoConfig {
 
    @Resource
    @Qualifier("secondaryDataSource")
    private DataSource secondaryDataSource;
 
    @Resource
    private JpaProperties jpaProperties;
 
    @Resource
    private HibernateProperties properties;
 
    @Bean(name = "entityManagerSecondary")
    public EntityManager entityManager(EntityManagerFactoryBuilder builder) {
        return entityManagerFactorySecondary(builder).getObject().createEntityManager();
    }
 
    @Bean(name = "entityManagerFactorySecondary")
    public LocalContainerEntityManagerFactoryBean entityManagerFactorySecondary(EntityManagerFactoryBuilder builder) {
        LocalContainerEntityManagerFactoryBean entityManagerFactory
                = builder
                .dataSource(secondaryDataSource)
                //.packages(classes)
                //设置实体类所在位置
                .packages("com.mm.dmp.t3cc.core.entity.two")
                .persistenceUnit("secondaryPersistenceUnit")
                .properties(properties.determineHibernateProperties(jpaProperties.getProperties(), new
                        HibernateSettings()))
                .build();
        return entityManagerFactory;
    }
 
    @Bean(name = "transactionManagerSecondary")
    public PlatformTransactionManager transactionManagerPrimary(EntityManagerFactoryBuilder builder) {
        return new JpaTransactionManager(entityManagerFactorySecondary(builder).getObject());
    }
}

如果你觉得这样比较麻烦，并且还有分库分表的需求，那么可以使用sharding jdbc来操作，移步这一篇文章

以上为个人经验，希望能给大家一个参考，也希望大家多多支持。

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