Spring数据JPA-多个启用jparepositories

Question

描述：com.cavion.services.UserDataService中得字段userDataRepo需要一个名为“Entity ManagerFactory”得bean,但找不到该bean.操作：考虑在您的配置中定义一个名为'Entity ManagerFactory‘的bean。

我需要在我的JPA存储库上指定entityManagerFactoryRef。

但是我有许多存储库类，其中一些使用Entitymanager'A'，另一些使用'B'。我当前的spring boot应用程序类是这样的

@SpringBootApplication(exclude = { DataSourceAutoConfiguration.class, HibernateJpaAutoConfiguration.class,
    DataSourceTransactionManagerAutoConfiguration.class })
@EnableTransactionManagement
@EntityScan("com.info.entity")
@ComponentScan({"com.info.services","com.info.restcontroller"})
@EnableJpaRepositories("com.info.repositories")
public class CavionApplication {

public static void main(String[] args) {
    SpringApplication.run(CavionApplication.class, args);
}
@Bean
public CommandLineRunner commandLineRunner(ApplicationContext ctx) {
    return args -> {

        System.out.println("Let's inspect the beans provided by Spring Boot:");

        String[] beanNames = ctx.getBeanDefinitionNames();
        Arrays.sort(beanNames);
        for (String beanName : beanNames) {
            System.out.println(beanName);
        }

    };
}}

Answer 1

为了让spring知道什么datasource与什么repository相关，您应该在@enablejparepositories注释中定义它。假设我们有两个实体，servers实体和domains实体，每个实体都有自己的Repo，然后每个存储库都有自己的JpaDataSource配置。

1.根据与存储库相关的数据源对所有存储库进行分组。例如：

domains实体的存储库（包:org.springdemo.multiple.datasources.Repository.domains):

package org.springdemo.multiple.datasources.repository.domains;

import org.springdemo.multiple.datasources.domain.domains.Domains;
import org.springframework.data.jpa.repository.JpaRepository;

public interface DomainsRepository extends JpaRepository<Domains,Long> {
}

package org.springdemo.multiple.datasources.repository.servers;

import org.springdemo.multiple.datasources.domain.servers.Servers;
import org.springframework.data.jpa.repository.JpaRepository;

public interface ServersRepository extends JpaRepository<Servers,Long> {
}

2.对于需要定义配置的每个JPA数据Soruce，在本例中，我展示了如何配置两个不同的数据源

domainsJpa配置：数据源和存储库之间的关系在basePackages值中定义，这就是为什么需要根据每个回购将使用的实体管理器将存储库分组在不同的包中的原因。

@Configuration
@EnableJpaRepositories(
        entityManagerFactoryRef = "domainsEntityManager",
        transactionManagerRef = "domainsTransactionManager",
        basePackages = {"org.springdemo.multiple.datasources.repository.domains"}
        )
public class DomainsConfig {

servers数据源配置：如您所见，basePackages值具有servers存储库的包名称，并且EntityManagerFactoryRef和TransactionManagerRef的值不同，以便spring将每个EntityManager分开。

@Configuration
@EnableJpaRepositories(
        entityManagerFactoryRef = "serversEntityManager",
        transactionManagerRef = "serversTransactionManager",
        basePackages = {"org.springdemo.multiple.datasources.repository.servers"}
        )
public class ServersConfig {

3.将一个数据源设置为主数据源

为了避免出现错误消息:org.springframework.boot.autocigure.orm.jpa.hibernatejpaAutoConfiguration中构造函数的参数0需要一个bean，但找到了2个:只是将其中一个数据源设置为@primary，在本例中，我选择servers数据源为primary：

@Bean("serversDataSourceProperties")
@Primary
@ConfigurationProperties("app.datasource.servers")
public DataSourceProperties serversDataSourceProperties(){
    return new DataSourceProperties();
}



@Bean("serversDataSource")
@Primary
@ConfigurationProperties("app.datasource.servers")
public DataSource serversDataSource(@Qualifier("serversDataSourceProperties") DataSourceProperties serversDataSourceProperties) {
    return serversDataSourceProperties().initializeDataSourceBuilder().build();
}

如果需要更多信息，请参阅每个配置的完整示例：

服务器JPA配置

@Configuration
@EnableJpaRepositories(
        entityManagerFactoryRef = "serversEntityManager",
        transactionManagerRef = "serversTransactionManager",
        basePackages = {"org.springdemo.multiple.datasources.repository.servers"}
        )
public class ServersConfig {

    @Bean(name = "serversEntityManager")
    public LocalContainerEntityManagerFactoryBean getServersEntityManager(EntityManagerFactoryBuilder builder,
                                                                          @Qualifier("serversDataSource") DataSource serversDataSource){


        return builder
                .dataSource(serversDataSource)
                .packages("org.springdemo.multiple.datasources.domain.servers")
                .persistenceUnit("servers")
                .properties(additionalJpaProperties())
                .build();

    }

    Map<String,?> additionalJpaProperties(){
        Map<String,String> map = new HashMap<>();

        map.put("hibernate.hbm2ddl.auto", "create");
        map.put("hibernate.dialect", "org.hibernate.dialect.MySQLDialect");
        map.put("hibernate.show_sql", "true");

        return map;
    }


    @Bean("serversDataSourceProperties")
    @Primary
    @ConfigurationProperties("app.datasource.servers")
    public DataSourceProperties serversDataSourceProperties(){
        return new DataSourceProperties();
    }



    @Bean("serversDataSource")
    @Primary
    @ConfigurationProperties("app.datasource.servers")
    public DataSource serversDataSource(@Qualifier("serversDataSourceProperties") DataSourceProperties serversDataSourceProperties) {
        return serversDataSourceProperties().initializeDataSourceBuilder().build();
    }

    @Bean(name = "serversTransactionManager")
    public JpaTransactionManager transactionManager(@Qualifier("serversEntityManager") EntityManagerFactory serversEntityManager){
        JpaTransactionManager transactionManager = new JpaTransactionManager();
        transactionManager.setEntityManagerFactory(serversEntityManager);

        return transactionManager;
    }
}

域JPA配置

@Configuration
@EnableJpaRepositories(
        entityManagerFactoryRef = "domainsEntityManager",
        transactionManagerRef = "domainsTransactionManager",
        basePackages = {"org.springdemo.multiple.datasources.repository.domains"}
        )
public class DomainsConfig {

    @Bean(name = "domainsEntityManager")
    public LocalContainerEntityManagerFactoryBean getdomainsEntityManager(EntityManagerFactoryBuilder builder
    ,@Qualifier("domainsDataSource") DataSource domainsDataSource){

        return builder
                .dataSource(domainsDataSource)
                .packages("org.springdemo.multiple.datasources.domain.domains")
                .persistenceUnit("domains")
                .properties(additionalJpaProperties())
                .build();

    }


    Map<String,?> additionalJpaProperties(){
        Map<String,String> map = new HashMap<>();

        map.put("hibernate.hbm2ddl.auto", "create");
        map.put("hibernate.dialect", "org.hibernate.dialect.H2Dialect");
        map.put("hibernate.show_sql", "true");

        return map;
    }


    @Bean("domainsDataSourceProperties")
    @ConfigurationProperties("app.datasource.domains")
    public DataSourceProperties domainsDataSourceProperties(){
        return new DataSourceProperties();
    }


    @Bean("domainsDataSource")
    public DataSource domainsDataSource(@Qualifier("domainsDataSourceProperties") DataSourceProperties domainsDataSourceProperties) {
        return domainsDataSourceProperties.initializeDataSourceBuilder().build();
    }

    @Bean(name = "domainsTransactionManager")
    public JpaTransactionManager transactionManager(@Qualifier("domainsEntityManager") EntityManagerFactory domainsEntityManager){
        JpaTransactionManager transactionManager = new JpaTransactionManager();
        transactionManager.setEntityManagerFactory(domainsEntityManager);

        return transactionManager;
    }

}

为了分离每个数据源，我将配置放在application.properties文件中，如下所示：

app.datasource.domains.url=jdbc:h2:mem:~/test
app.datasource.domains.driver-class-name=org.h2.Driver


app.datasource.servers.driver-class-name=com.mysql.jdbc.Driver
app.datasource.servers.url=jdbc:mysql://localhost:3306/v?autoReconnect=true&useSSL=false
app.datasource.servers.username=myuser
app.datasource.servers.password=mypass