具有多个数据源和外部配置的 Spring Boot，Spring JPA

Posted 2023-02-26

【中文标题】具有多个数据源和外部配置的 Spring Boot，Spring JPA

【英文标题】：Spring Boot with multiple datasources and external configuration, Spring JPA

【发布时间】：2015-07-01 09:22:22

【问题描述】：

我有一个带有 2 个外部 jar 的简单 Spring Boot 应用程序。每个 jar 都使用 Spring JPA 并完全配置为独立工作。

Jar1

JPA 存储库

@Repository
public interface QuarterRepository extends JpaRepository<Quarter, Long>

实体

@Entity
public class Quarter implements Serializable 
    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private Long id;...

配置

@Configuration
@Import(RepositoryConfig.class)
public class OnlineJpaAppConfig

    @Bean(name = "onlinejpaAppConfigConfigurer")
    public static PropertyPlaceholderConfigurer getPropertyPlaceholderConfigurer()            
        PropertyPlaceholderConfigurer ppc = new PropertyPlaceholderConfigurer();
        ppc.setLocation(new ClassPathResource("/de/comp/onlinejpa/application.properties"));
        ppc.setIgnoreUnresolvablePlaceholders(true);
        return ppc;
    
  


@Configuration
@EnableJpaRepositories(basePackages = "de.comp.onlinejpa.repository",
        entityManagerFactoryRef = "onlinejpaentityManagerFactory",
        transactionManagerRef = "onlinejpaTransactionManager")
@EnableTransactionManagement
public class RepositoryConfig 

    @Value("$jdbc.driverClassName")
    private String driverClassName;
    @Value("$jdbc.url")
    private String url;
    @Value("$jdbc.username")
    private String username;
    @Value("$jdbc.password")
    private String password;

    @Value("$hibernate.dialect")
    private String hibernateDialect;
    @Value("$hibernate.show_sql")
    private String hibernateShowSql;
    @Value("$hibernate.hbm2ddl.auto")
    private String hibernateHbm2ddlAuto;

    private static final String QUALIFIER = "onlinejpa";

    @Bean(name = "onlinejpaentityManagerFactory")
    public LocalContainerEntityManagerFactoryBean entityManagerFactory() 
        LocalContainerEntityManagerFactoryBean em = new LocalContainerEntityManagerFactoryBean();
        em.setDataSource(dataSource());
        em.setPackagesToScan(new String[]"de.comp.onlinejpa.entity");
        em.setPersistenceUnitName("onlinejpa");
        JpaVendorAdapter vendorAdapter = new HibernateJpaVendorAdapter();
        em.setJpaVendorAdapter(vendorAdapter);
        em.setJpaProperties(additionalProperties());

        return em;
    

    @Bean(name = "onlinejpaDataSource")
    public DataSource dataSource() 
        DriverManagerDataSource dataSource = new DriverManagerDataSource();
        dataSource.setDriverClassName(driverClassName);
        dataSource.setUrl(url);
        dataSource.setUsername(username);
        dataSource.setPassword(password);
        return dataSource;
    

    @Bean(name = "onlinejpaTransactionManager")
    public PlatformTransactionManager transactionManager(@Qualifier(value = "onlinejpaentityManagerFactory") EntityManagerFactory onlinejpaentityManagerFactory) 
        JpaTransactionManager transactionManager = new JpaTransactionManager();
        transactionManager.setEntityManagerFactory(onlinejpaentityManagerFactory);

        return transactionManager;
    

    @Bean(name = "onlinejpaExceptionTranslation")
    public PersistenceExceptionTranslationPostProcessor exceptionTranslation() 
        return new PersistenceExceptionTranslationPostProcessor();
    

    Properties additionalProperties() 

        Properties properties = new Properties();
        properties.setProperty("hibernate.hbm2ddl.auto", hibernateHbm2ddlAuto);
        properties.setProperty("hibernate.dialect", hibernateDialect);
        return properties;
    

第二个 jar 看起来和 Jar1 几乎一样，除了 bean 和包名

@EnableJpaRepositories(basePackages = "de.comp.aisjpa.repository", 
        entityManagerFactoryRef = "aisjpaentityManagerFactory",
        transactionManagerRef = "aisjpatransactionManager")
@EnableTransactionManagement
public class RepositoryConfig 

    @Value("$jdbc.driverClassName")
    private String driverClassName;
    @Value("$jdbc.url")
    private String url;
    @Value("$jdbc.username")
    private String username;
    @Value("$jdbc.password")
    private String password;

    @Value("$hibernate.dialect")
    private String hibernateDialect;
    @Value("$hibernate.show_sql")
    private String hibernateShowSql;
    @Value("$hibernate.hbm2ddl.auto")
    private String hibernateHbm2ddlAuto;

     private static final String QUALIFIER = "aisjpa";


    @Bean(name = "aisjpaentityManagerFactory")
    public LocalContainerEntityManagerFactoryBean entityManagerFactory() 
        LocalContainerEntityManagerFactoryBean em = new LocalContainerEntityManagerFactoryBean();
        em.setDataSource(aisdataSource());
        em.setPackagesToScan(new String[]"de.comp.aisjpa.entity");
        em.setPersistenceUnitName("ais");
        JpaVendorAdapter vendorAdapter = new HibernateJpaVendorAdapter();
        em.setJpaVendorAdapter(vendorAdapter);
        em.setJpaProperties(additionalProperties());

        return em;
    



    @Bean(name = "aisjpadatasource")
    public DataSource aisdataSource() 
        DriverManagerDataSource dataSource = new DriverManagerDataSource();
        dataSource.setDriverClassName(driverClassName);
        dataSource.setUrl(url);
        dataSource.setUsername(username);
        dataSource.setPassword(password);
        return dataSource;
    


    @Bean(name = "aisjpatransactionManager")
    public PlatformTransactionManager transactionManager(@Qualifier(value = "aisjpaentityManagerFactory") EntityManagerFactory aisjpaentityManagerFactory) 
        JpaTransactionManager transactionManager = new JpaTransactionManager();
        transactionManager.setEntityManagerFactory(aisjpaentityManagerFactory);

        return transactionManager;
    


    @Bean(name = "aisjpaexceptionTranslation")
    public PersistenceExceptionTranslationPostProcessor exceptionTranslation() 
        return new PersistenceExceptionTranslationPostProcessor();
    

    Properties additionalProperties() 
        Properties properties = new Properties();
        properties.setProperty("hibernate.hbm2ddl.auto", hibernateHbm2ddlAuto);
        properties.setProperty("hibernate.dialect", hibernateDialect);
        return properties;
    

在 Jar1 中运行这个 Main 类会得到预期的结果..（与 Jar2 相同）

public class App 

    public static void main(String[] args) 

        AnnotationConfigApplicationContext ctx = new AnnotationConfigApplicationContext(OnlineJpaAppConfig.class);

        QuarterRepository quarterRepository = ctx.getBean("quarterRepository", QuarterRepository.class);

        List<Quarter> quarters = quarterRepository.findAll();

        for (Quarter quarter : quarters) 

            System.out.println(quarter.getQuarter());

        
    

这是我的 Spring Boot 应用程序的启动类

@SpringBootApplication(exclude = DataSourceAutoConfiguration.class,
        HibernateJpaAutoConfiguration.class,
        DataSourceTransactionManagerAutoConfiguration.class  )
@Import( KVLdapAppConfig.class, OnlineJpaAppConfig.class,AISAppConfig.class)

public class ServerApplication 

    public static void main(String[] args) 

        SpringApplication.run(ServerApplication.class, args);
    

服务器启动没有问题，但是在配置 jpa 的过程中出现了一些问题。持久性单元 ais 的配置应使用 Oracle 方言和驱动程序。似乎它采用了 Jar1 的配置。

Building JPA container EntityManagerFactory for persistence unit 'onlinejpa'
HCANN000001: Hibernate Commons Annotations 4.0.1.Final
HHH000412: Hibernate Core 4.2.0.Final
HHH000206: hibernate.properties not found
HHH000021: Bytecode provider name : javassist
HHH000204: Processing PersistenceUnitInfo [


HHH000130: Instantiating explicit connection provider: org.hibernate.ejb.connection.InjectedDataSourceConnectionProvider
HHH000400: Using dialect: org.hibernate.dialect.mysql5Dialect
HHH000268: Transaction strategy: org.hibernate.engine.transaction.internal.jdbc.JdbcTransactionFactory
HHH000397: Using ASTQueryTranslatorFactory
Loaded JDBC driver: com.mysql.jdbc.Driver
Building JPA container EntityManagerFactory for persistence unit 'ais'
HHH000204: Processing PersistenceUnitInfo [


HHH000130: Instantiating explicit connection provider: org.hibernate.ejb.connection.InjectedDataSourceConnectionProvider
HHH000400: Using dialect: **org.hibernate.dialect.MySQL5Dialect**
HHH000268: Transaction strategy: org.hibernate.engine.transaction.internal.jdbc.JdbcTransactionFactory
HHH000397: Using ASTQueryTranslatorFactory
Loaded JDBC driver: com.mysql.jdbc.Driver

下一个问题是数据库访问。 Spring 不知道它应该使用哪个事务管理器

: No qualifying bean of type [org.springframework.transaction.PlatformTransactionManager] is defined: expected single matching bean but found 2: aisjpatransactionManager,onlinejpaTransactionManager

将一个 tx 管理器设置为 @Primary 解决了上述问题，但以在另一个库中找不到表结束，这是错误配置的 tx 管理器/持久性单元的原因。

也许我的问题是为每个单独的 jar 创建 LocalContainerEntityManagerFactoryBean 。相反，我应该使用以下代码来设置我的数据库连接，但这会破坏我的个人库。

public LocalContainerEntityManagerFactoryBean internalEntityManagerFactory(
        EntityManagerFactoryBuilder builder) 
    Map<String, Object> properties = new HashMap<String, Object>();
    properties.put("hibernate.hbm2ddl.auto", "create");
    return builder
            .dataSource(internalDataSource())
            .packages("package here")
            .persistenceUnit("onlinjpa")
            .properties(properties)
            .build();

如何让每个单独的 jar 在 Spring Boot 应用程序中工作。

这是一个使用 Sping Boot 设置多个数据源的链接，但我不想在 Spring Boot 应用程序中配置我的 libs 数据源。

Multiple data source and schema creation in Spring Boot

【参考方案1】：

问题是注入了错误的属性值，这可能是由每个 jar 中的 PropertyPlaceholderConfigurer 的静态调用引起的。

随便用

    @PropertySource("classpath:/de/comp/aisjpa/application.properties")
    public class RepositoryConfig

    @Autowired
    private Environment env;

    dataSource.setUrl(env.getRequiredProperty("jdbc.url"));
    ....

或者将静态调用留给PropertyPlaceholderConfigurer，但在您的application.properties 中为属性添加前缀，这样每个属性值在您的整个应用程序中都是唯一的

来自

jdbc.driverClassName=oracle.jdbc.OracleDriver

到

jar1.jdbc.driverClassName=oracle.jdbc.OracleDriver