从 Migrate 迁移到 Spring MVC 4 + Hibernate5

Posted 2023-02-27

【中文标题】从 Migrate 迁移到 Spring MVC 4 + Hibernate5

【英文标题】：Migrating from Migrate to Spring MVC 4 + Hibernate5

【发布时间】：2017-08-03 22:39:51

【问题描述】：

我正在将应用程序从 Jersey 1.18、Spring 3、Hibernate 3.6、Maven 迁移到全新的架构：Spring 4.3（通过 Spring Boot）、Hibernate 5和 Gradle。

在将 Spring application.xml“移植”到 Code-Base 配置期间，我遇到了以下异常：

创建名为“jpaContext”的 bean 时出错：依赖项不满足 ... 没有找到符合条件的 bean 依赖项 [java.util.Set]

这里是长堆栈跟踪

2017-03-13 19:44:42.814  WARN 40010 --- [           main] ationConfigEmbeddedWebApplicationContext : Exception encountered during context initialization - cancelling refresh attempt: org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'jpaContext': Unsatisfied dependency expressed through constructor parameter 0; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean found for dependency [java.util.Set<javax.persistence.EntityManager>]: expected at least 1 bean which qualifies as autowire candidate. Dependency annotations: 
2017-03-13 19:44:42.816  INFO 40010 --- [           main] o.s.j.e.a.AnnotationMBeanExporter        : Unregistering JMX-exposed beans on shutdown
2017-03-13 19:44:42.825  INFO 40010 --- [           main] o.apache.catalina.core.StandardService   : Stopping service Tomcat
2017-03-13 19:44:42.860  INFO 40010 --- [           main] utoConfigurationReportLoggingInitializer : 

Error starting ApplicationContext. To display the auto-configuration report re-run your application with 'debug' enabled.
2017-03-13 19:44:42.995 ERROR 40010 --- [           main] o.s.b.d.LoggingFailureAnalysisReporter   : 

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

Description:

Parameter 0 of constructor in org.springframework.data.jpa.repository.support.DefaultJpaContext required a bean of type 'java.util.Set' that could not be found.


Action:

Consider defining a bean of type 'java.util.Set' in your configuration.

事实是我没有在我的代码中定义 DefaultJpaContext：

@Configuration
@EnableTransactionManagement
@EnableAspectJAutoProxy(proxyTargetClass = true)
public class DatabaseConfig 

    @Autowired private Environment env;
    @Autowired private DataSource dataSource;
    @Autowired private SessionFactory sessionFactory;

    private static final String DB_DRIVER_CLASS_NAME = "com.mysql.jdbc.Driver";
    private static final String HIBERNATE_DIALECT    = "org.hibernate.dialect.MySQL5Dialect";
    private static final String HIBERNATE_VALIDATION = "validate";
    private static final String SHOW_SQL             = "false";
    private static final String ENTITY_PACKAGE       = MainEntity.class.getPackage().getName();

    final Logger log = LoggerFactory.getLogger(DatabaseConfig.class);


    @Bean
    public DataSource dataSource() 
        final String driverName = env.getProperty("db.driver", DB_DRIVER_CLASS_NAME);
        final String url        = env.getProperty("db.url");
        final String username   = env.getProperty("db.username");
        final String password   = env.getProperty("db.password");
        final DriverManagerDataSource dataSource = new DriverManagerDataSource();

        if (log.isInfoEnabled()) 
            log.info("Database Configuration:");
            log.info("Setting driverName to ", driverName);
            log.info("Setting url to ", url);
            log.info("Setting username to ", username);
            if (StringUtils.isEmpty(password)) log.warn("Password not specified");
            else log.info("Setting password");
        

        dataSource.setDriverClassName(driverName);
        dataSource.setUrl(url);
        dataSource.setUsername(username);
        dataSource.setPassword(password);
        return dataSource;
    

    @Bean
    public LocalSessionFactoryBean sessionFactory()
        LocalSessionFactoryBean sessionFactory = new LocalSessionFactoryBean();
        sessionFactory.setDataSource(dataSource);
        sessionFactory.setPackagesToScan(new String[] ENTITY_PACKAGE);

        // Hibernate properties
        Properties additionalProperties = new Properties();
        additionalProperties.put("hibernate.dialect"     , env.getProperty("db.dialect"   , HIBERNATE_DIALECT));
        additionalProperties.put("hibernate.hbm2ddl.auto", env.getProperty("db.validation", HIBERNATE_VALIDATION));
        additionalProperties.put("hibernate.show_sql"    , env.getProperty("db.sql.show"  , SHOW_SQL));

        sessionFactory.setHibernateProperties(additionalProperties);
        return sessionFactory;
    

    @Bean
    public HibernateTransactionManager transactionManager()
        HibernateTransactionManager transactionManager = new HibernateTransactionManager();
        transactionManager.setSessionFactory(sessionFactory);
        return transactionManager;
    

更新

这是一个 gradle build：

compile('org.springframework.boot:spring-boot-starter-data-jpa')
// ...
compile('org.springframework.boot:spring-boot-starter-security')
compile('org.springframework.boot:spring-boot-starter-web')
compile group: 'org.hibernate'        , name: 'hibernate-core'     , version: '5.2.8.Final'
// ...

我错过了什么？

谢谢，大卫。

【问题讨论】：

DefaultJpaContext 在自动配置中定义。按照错误报告中的建议在启用调试的情况下运行以查看详细信息。但是你正在做的事情是不必要的。所有属性都可以在application.properties 中定义，spring-boot 会选择它。

【参考方案1】：

根据 Spring Boot 错误消息，它无法构建构造函数需要 Set<javax.persistence.EntityManager> entityManagers 的 DefaultJpaContext bean。

看起来你的pom.xml（或build.gradle）中有Spring-Data 依赖项，这需要jpa EntityManagerFactory 而你有Hibernate（LocalSessionFactoryBean）的东西。你必须有DefaultJpaContext bean 吗？

【讨论】：

是的，我有 spring-boot-starter-data-jpa 依赖项，但没有可用的 @Transactional 注释。我真的不需要实体管理器，因为我在这个项目中使用了 SessionFactory。

如果您的问题只是 @ Transactional 注释，那么只需添加 spring-tx 作为您的依赖项。这里的重点是尽量减少您声明的依赖关系。这是Spring-boot 的少数缺点之一，我们只是盲目地声明了一堆starters，它们有时会引入很多我们实际上不需要的依赖项。就像你的情况一样，你不需要 JPA，只需要休眠相关的 jar，那么你不需要接触那些 jpa 启动器。