如果是两个jpa数据源，怎么配置不上呢？

Question

首先，我的目录结构是这样的：

然后，我的配置是这样的：

@Configuration
public class DbConfig {

    @Primary
    @Bean("db1EntityManager")
    public LocalContainerEntityManagerFactoryBean db1EntityManager() {
        HibernateJpaVendorAdapter vendorAdapter = new HibernateJpaVendorAdapter();
        vendorAdapter.setGenerateDdl(true);

        LocalContainerEntityManagerFactoryBean em = new LocalContainerEntityManagerFactoryBean();

        Map<String, String> map = new HashMap<>();
        map.put("hibernate.dialect", "org.hibernate.dialect.MySQLDialect");

        em.setJpaPropertyMap(map);

        em.setDataSource(db1DataSource());
        em.setPackagesToScan("com.gaojingsi.transaction.muiltidatasourcetransactiondemo.entity.db1");
        em.setJpaVendorAdapter(vendorAdapter);

        return em;
    }

    @Primary
    @Bean(name = "db1DataSource")
    @ConfigurationProperties(prefix = "spring.datasource.db1")
    public DataSource db1DataSource() {
        return DataSourceBuilder.create().build();
    }

    @Bean("db2EntityManager")
    public LocalContainerEntityManagerFactoryBean db2EntityManager() {
        HibernateJpaVendorAdapter vendorAdapter = new HibernateJpaVendorAdapter();
        vendorAdapter.setGenerateDdl(true);

        LocalContainerEntityManagerFactoryBean em = new LocalContainerEntityManagerFactoryBean();

        Map<String, String> map = new HashMap<>();
        map.put("hibernate.dialect", "org.hibernate.dialect.MySQLDialect");

        em.setJpaPropertyMap(map);

        em.setDataSource(db2DataSource());
        em.setPackagesToScan("com.gaojingsi.transaction.muiltidatasourcetransactiondemo.entity.db2");
        em.setJpaVendorAdapter(vendorAdapter);

        return em;
    }

    @Bean(name = "db2DataSource")
    @ConfigurationProperties(prefix = "spring.datasource.db2")
    public DataSource db2DataSource() {
        return DataSourceBuilder.create().build();
    }

    @Primary
    @Bean
    public PlatformTransactionManager transactionManager() {
        JpaTransactionManager jpaTransactionManager1 = new JpaTransactionManager();
        jpaTransactionManager1.setEntityManagerFactory(db1EntityManager().getObject());
        JpaTransactionManager jpaTransactionManager2 = new JpaTransactionManager();
        jpaTransactionManager2.setEntityManagerFactory(db2EntityManager().getObject());
        ChainedTransactionManager chainedTransactionManager = new ChainedTransactionManager(jpaTransactionManager1, jpaTransactionManager2);
        return chainedTransactionManager;
    }

}

然后启动就报错：

***************************
APPLICATION FAILED TO START
***************************

Description:

Field db1UserDAO in com.gaojingsi.transaction.muiltidatasourcetransactiondemo.service.impl.UserServiceImpl required a bean named 'entityManagerFactory' that could not be found.

The injection point has the following annotations:
	- @org.springframework.beans.factory.annotation.Autowired(required=true)


Action:

Consider defining a bean named 'entityManagerFactory' in your configuration.

请问老师，还要做什么配置吗？

Answer 1

大漠风 2020-01-06 02:26:16

使用spring data配置多个数据源，比较好的方式是通过包名将不同的数据库相关的模块分开，然后，你的`DbConfig`也需要分成两个配置类，分别配置两个数据源的jpa配置，通过`@EnableJpaRepositories`的标签来控制不同的包名下的DAO类要使用哪个jpa的配置。

具体的方法，我找了一个链接，你可以参考一下:

https://www.baeldung.com/spring-data-jpa-multiple-databases