尝试使用hibernate持久化实体时出错（MappingException：未知实体）

时间：2015-12-26 19:13:19

标签： java hibernate maven

我在一个独立的maven java应用程序中使用hibernate 5.0.6和hibernate注释3.5.6-Final和mysql 5.1.37。

我正在尝试使用简单的持久性示例，但在调用save时收到以下错误：

0    [main] ERROR edu.uci.ics.crawler4j.crawler.CrawlController  - Error    happened
org.hibernate.MappingException: Unknown entity: br.com.alexpfx.supermarket.crawler.model.domain.Product

通过配置文件中的映射类指向类。但它无法找到。 

        <mapping class="br.com.alexpfx.supermarket.crawler.model.domain.Product" />

但是当我在HibernateUtil中执行此操作时：

        configure.addAnnotatedClass(Product.class);
        configure.addAnnotatedClass(Manufacturer.class);

有效。但我想指出在xml文件中映射类。

我发现了几个与此相关的错误但发现没有解决方案解决了我的问题。我想我做错了。

错误的完整堆栈跟踪：

0    [main] ERROR edu.uci.ics.crawler4j.crawler.CrawlController  - Error happened
org.hibernate.MappingException: Unknown entity: br.com.alexpfx.supermarket.crawler.model.domain.Product
    at org.hibernate.internal.SessionFactoryImpl.getEntityPersister(SessionFactoryImpl.java:781)
    at org.hibernate.internal.SessionImpl.getEntityPersister(SessionImpl.java:1520)
    at org.hibernate.event.internal.AbstractSaveEventListener.saveWithGeneratedId(AbstractSaveEventListener.java:100)
    at org.hibernate.event.internal.DefaultSaveOrUpdateEventListener.saveWithGeneratedOrRequestedId(DefaultSaveOrUpdateEventListener.java:192)
    at org.hibernate.event.internal.DefaultSaveEventListener.saveWithGeneratedOrRequestedId(DefaultSaveEventListener.java:38)
    at org.hibernate.event.internal.DefaultSaveOrUpdateEventListener.entityIsTransient(DefaultSaveOrUpdateEventListener.java:177)
    at org.hibernate.event.internal.DefaultSaveEventListener.performSaveOrUpdate(DefaultSaveEventListener.java:32)
    at org.hibernate.event.internal.DefaultSaveOrUpdateEventListener.onSaveOrUpdate(DefaultSaveOrUpdateEventListener.java:73)
    at org.hibernate.internal.SessionImpl.fireSave(SessionImpl.java:679)
    at org.hibernate.internal.SessionImpl.save(SessionImpl.java:671)
    at org.hibernate.internal.SessionImpl.save(SessionImpl.java:666)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:497)
    at org.hibernate.context.internal.ThreadLocalSessionContext$TransactionProtectionWrapper.invoke(ThreadLocalSessionContext.java:338)
    at com.sun.proxy.$Proxy19.save(Unknown Source)
    at br.com.alexpfx.supermarket.crawler.crawler.mercadoribeirao.MercadoRibeiraoCrawler.init(MercadoRibeiraoCrawler.java:47)
    at br.com.alexpfx.supermarket.crawler.crawler.Crawler.<init>(Crawler.java:16)
    at br.com.alexpfx.supermarket.crawler.crawler.mercadoribeirao.MercadoRibeiraoCrawler.<init>(MercadoRibeiraoCrawler.java:26)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
    at java.lang.reflect.Constructor.newInstance(Constructor.java:422)
    at java.lang.Class.newInstance(Class.java:442)
    at edu.uci.ics.crawler4j.crawler.CrawlController.start(CrawlController.java:158)
    at edu.uci.ics.crawler4j.crawler.CrawlController.start(CrawlController.java:133)
    at br.com.alexpfx.supermarket.crawler.crawler.CrawlerStarter.start(CrawlerStarter.java:41)
    at br.com.alexpfx.supermarket.crawler.Main.save(Main.java:29)
    at br.com.alexpfx.supermarket.crawler.Main.main(Main.java:14)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:497)
    at com.intellij.rt.execution.application.AppMain.main(AppMain.java:144)

配置文件位于：project \ src \ main \ resources \ hibernate.cfg.xml 

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-configuration PUBLIC
    "-//Hibernate/Hibernate Configuration DTD 3.0//EN"
    "http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">
<hibernate-configuration>

    <session-factory>
        <property name="connection.driver_class">com.mysql.jdbc.Driver</property>
        <property name="dialect">org.hibernate.dialect.MySQLDialect</property>
        <property name="connection.url">jdbc:mysql://localhost:3306/smket</property>
        <property name="connection.username">alex</property>
        <property name="connection.password">123alex</property>
        <property name="connection.pool_size">5</property>
        <property name="hibernate.hbm2ddl.auto">update</property>
        <property name="show_sql">true</property>
        <property name="hibernate.current_session_context_class">thread</property>
        <mapping class="br.com.alexpfx.supermarket.crawler.model.domain.Product" />
       <mapping class="br.com.alexpfx.supermarket.crawler.model.domain.Manufacturer" />
    </session-factory>

</hibernate-configuration>

Hibernate util：

public class HibernateUtil {
    private static final SessionFactory sessionFactory = buildSessionFactory();

    private static SessionFactory buildSessionFactory() {
        try {
            Configuration configure = new Configuration().configure("hibernate.cfg.xml");

            /*
            configure.addAnnotatedClass(Product.class);
            configure.addAnnotatedClass(Manufacturer.class);
            */

            ServiceRegistry serviceRegistry = new StandardServiceRegistryBuilder().applySettings(configure.getProperties()).build();
            return configure.buildSessionFactory(serviceRegistry);
        } catch (Throwable ex) {
            System.err.println("Initial SessionFactory creation failed." + ex);
            throw new ExceptionInInitializerError(ex);
        }
    }

    public static SessionFactory getSessionFactory() {
        return sessionFactory;
    }

    public static void shutdown() {
        getSessionFactory().close();
    }

}

pojo类：

package br.com.alexpfx.supermarket.crawler.model.domain;

import javax.persistence.*;

@Entity
@Table(name = "tb_produtos")
public class Product implements BaseEntity {


    public Product() {
    }

    Product(Integer id, Manufacturer manufacturer, String description, String url, Keywords keywords) {
        this.id = id;
        this.manufacturer = manufacturer;
        this.description = description;
        this.url = url;
        this.keywords = keywords;
    }

    @Id
    @GeneratedValue
    private Integer id;

    @ManyToOne
    @JoinColumn(name = "ID_FABRICANTE")
    private Manufacturer manufacturer;

    @Column(name = "DESCRICAO")
    private String description;

    @Column(name = "URL")
    private String url;

    @Transient
    private Keywords keywords;

    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public Manufacturer getManufacturer() {
        return manufacturer;
    }

    public void setManufacturer(Manufacturer manufacturer) {
        this.manufacturer = manufacturer;
    }

    public String getDescription() {
        return description;
    }

    public void setDescription(String description) {
        this.description = description;
    }

    public String getUrl() {
        return url;
    }

    public void setUrl(String url) {
        this.url = url;
    }

    public Keywords getKeywords() {
        return keywords;
    }

    public void setKeywords(Keywords keywords) {
        this.keywords = keywords;
    }
}

2 个答案:

答案 0 :(得分：2)

Hibernate 5配置构建已经是一个熟悉的问题了。你不能使用Hibernate 4配置方法来配置Hibernate 5.所以只需使用这个

private static SessionFactory buildSessionFactory() {
        try {
             return new Configuration().configure().buildSessionFactory();
        } catch (Throwable ex) {
            System.err.println("Initial SessionFactory creation failed." + ex);
            throw new ExceptionInInitializerError(ex);
        }
}

您可以参考this了解其他说明。我已经实现了一个适用于Hibernate 4和Hibernate 5的配置构建器，您也可以查看它ConfigurationBuilder。

答案 1 :(得分：1)

您没有指定hibernate配置文件hibernate.cfg.xml的位置。

hibernate.cfg.xml文件是设置与数据库交互所需的所有配置的位置。因此，数据库在那里定义，以及数据库用户凭据。方言设置为MySQL，驱动程序为com.mysql.jdbc.Driver。还有一个mapping属性，其中定义了实体类。 您还可以在那里设置特定的数据库选项，例如每次创建sessionFactory时是创建架构还是仅更新架构。这是在hibernate.hbm2ddl.auto属性中配置的，该属性设置为update。因此架构只会更新。如果将此属性设置为create，则每次运行应用程序时，都会重新创建架构，从而删除以前的数据。此处设置的另一个属性是show_sql，它指定sql查询是否将显示在控制台或记录器中。 首先，getSessionFactory()是一种方法，它提供SessionFactory，Session的创建者，Java应用程序和Hibernate之间的基本接口。 SessionFactory使用StandardServiceRegistryBuilder构建，使用Configuration。您可以在Configuration指定创建SessionFactory时要使用的属性和映射文档。 因此，与数据库交互的每个方法都会获得Session，使用getSessionFactory()，并使用openSession()的{​​{1}} API方法。

SessionFactory
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