为什么我的休眠实体（消息）没有映射？

Question

我正在使用带有配置类的 spring boot 和 hibernate。我的实体没有被映射。请参阅下面的错误。在查看了其他一些关于此的 stackoverflow 页面后，我仍然无法弄清楚。

我认为以下是正确的：HQL、@Entity、@Table

错误。

org.hibernate.hql.internal.ast.QuerySyntaxException: Message is not mapped
at org.hibernate.hql.internal.ast.util.SessionFactoryHelper.requireClassPersister(SessionFactoryHelper.java:169) ~[hibernate-core-5.4.2.Final.jar:5.4.2.Final]
    at org.hibernate.hql.internal.ast.tree.FromElementFactory.addFromElement(FromElementFactory.java:91) ~[hibernate-core-5.4.2.Final.jar:5.4.2.Final]
    at org.hibernate.hql.internal.ast.tree.FromClause.addFromElement(FromClause.java:79) ~[hibernate-core-5.4.2.Final.jar:5.4.2.Final]

实体。

import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.Table;

@Entity(name = "strunk.entities")
@Table(name = "Message")
public class Message {

code...
}

DAO 类

import java.util.List;

import org.hibernate.HibernateException;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.Transaction;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Repository;

import strunk.entities.Message;

@Repository
public class MessageRepoImpl implements MessageRepo {
    
    @Autowired
    private SessionFactory sf;

    @Override
    public List<Message> getMessages() {
        Session sess = sf.openSession();
        List<Message> messages = null;

        try {
            messages = sess.createQuery("FROM Message").list();
        } catch (HibernateException e) {
            e.printStackTrace();
        } finally {
            sess.close();
        }
        
        return messages;
    }

    more code...
}

当我将 getMessages 方法体替换为以下内容时，它可以工作

        Session sess = sf.openSession();
        List<Message> messages = sess.createNativeQuery(
                "SELECT * FROM Message" )
            .list();
        return messages;

数据库表名是'Message'。

SpringBoot 类

@SpringBootApplication(exclude= HibernateJpaAutoConfiguration.class)
@ComponentScan("strunk")
@EnableJpaRepositories("strunk")
@EntityScan("strunk")
public class InstantMessengeTranslatorApplication {

    public static void main(String[] args) {
        SpringApplication.run(InstantMessengeTranslatorApplication.class, args);
    }

}

休眠配置类

package strunk.config;

import java.io.FileInputStream;
import java.util.Properties;
import javax.sql.DataSource;
import org.hibernate.SessionFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.PropertySource;
import org.springframework.jdbc.datasource.DriverManagerDataSource;
import org.springframework.orm.hibernate5.HibernateTransactionManager;
import org.springframework.orm.hibernate5.LocalSessionFactoryBean;
import org.springframework.transaction.PlatformTransactionManager;
import org.springframework.transaction.annotation.EnableTransactionManagement;


@Configuration
@EnableTransactionManagement
@PropertySource(value = {"classpath:application.properties"})
public class HibernateConfig {
    
    @Value("${spring.datasource.driver-class-name}")
    private String driverClass;
    @Value("${spring.datasource.url}")
    private String url;
    @Value("${spring.datasource.username}")
    private String username;
    @Value("${spring.datasource.password}")
    private String password;
    @Value("${hibernate.dialect}")
    private String dialect;
    
    @Bean
    public DataSource getDatasource(){
        DriverManagerDataSource datasource = new DriverManagerDataSource(url, username, password);
        datasource.setDriverClassName(driverClass);
        return datasource;
    }
    
    private Properties hibernateProperties() {
        Properties properties = new Properties();
        properties.put("hibernate.dialect", dialect);
        properties.put("hibernate.hbm2ddl.auto", "update");
        properties.put("hibernate.show_sql", "true");
        properties.put("hibernate.format_sql", "true");
        return properties;
    }
    
    @Bean
    public LocalSessionFactoryBean sessionFactory(){
        LocalSessionFactoryBean factory = new LocalSessionFactoryBean();
        factory.setDataSource(getDatasource());
        factory.setHibernateProperties(hibernateProperties());
        factory.setPackagesToScan(new String[] {"com.xadmin.springboothibernate.model"});
        return factory;
    }
    
    @Bean
    @Autowired
    public HibernateTransactionManager transactionManager(SessionFactory factory)
    {
        HibernateTransactionManager transactionManger = new HibernateTransactionManager();
        transactionManger.setSessionFactory(factory);
        return transactionManger;   
    }
}

我错过了什么？

Answer 1

在 spring bean 初始化期间，使您的实体类正在初始化。如果它没有添加到组件扫描中，则它不会被视为 bean 类，Hibernate 将通过错误。

Answer 2

问题是在 Hibernate 配置类中，setPackagesToScan() 引用了不正确的包。谢谢亚历克斯。