jpa多数据源时Hibernate配置自动生成表不生效

偏执的太偏执、 2021-11-26 15:08 251阅读 0赞

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。

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly90aWFueWFsZWkuYmxvZy5jc2RuLm5ldA_size_16_color_FFFFFF_t_70][]

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。

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly90aWFueWFsZWkuYmxvZy5jc2RuLm5ldA_size_16_color_FFFFFF_t_70 1][]

来看一下HibernateProperties![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly90aWFueWFsZWkuYmxvZy5jc2RuLm5ldA_size_16_color_FFFFFF_t_70 2][]

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。

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly90aWFueWFsZWkuYmxvZy5jc2RuLm5ldA_size_16_color_FFFFFF_t_70 3][]

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。

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly90aWFueWFsZWkuYmxvZy5jc2RuLm5ldA_size_16_color_FFFFFF_t_70 4][]

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：[https://tianyalei.blog.csdn.net/article/details/98057916][https_tianyalei.blog.csdn.net_article_details_98057916]

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[https_tianyalei.blog.csdn.net_article_details_98057916]: https://tianyalei.blog.csdn.net/article/details/98057916