Java Hibernate：没有找到查询类的持久类：SELECT p FROM entity.Presentation p

Hibernate: no persistent classes found for query class: SELECT p FROM entity.Presentation p

提问by Maxim Geerinck

I am trying to persist my classes but it always throws me this error.

我试图坚持我的课程，但它总是向我抛出这个错误。

This is my hibernate.cfg.xml

这是我的 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>
    <!-- SQL dialect -->
    <property name="hibernate.dialect">org.hibernate.dialect.MySQLDialect</property>

    <!-- Database connection settings -->
    <property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property>
    <property name="hibernate.connection.url">jdbc:mysql://localhost:3306/Projecten2?zeroDateTimeBehavior=convertToNull</property>
    <property name="hibernate.connection.username">MyUser</property>
    <property name="hibernate.connection.password">MyPass</property>
    <property name="hibernate.current_session_context_class">org.hibernate.context.ThreadLocalSessionContext</property>

    <!-- Echo all executed SQL to stdout -->
    <property name="show_sql">false</property>

    <!-- Mappings -->
    <mapping class="entity.Presentation"/>
  </session-factory>
</hibernate-configuration>

And this is the class i am trying to persist

这是我试图坚持的课程

/*
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 * To change this template file, choose Tools | Templates
 * and open the template in the editor.
 */

package entity;


import java.util.List;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.ManyToMany;
import javax.persistence.ManyToOne;
import javax.persistence.Temporal;
import javax.persistence.TemporalType;
import org.eclipse.persistence.jpa.jpql.parser.DateTime;
import org.hibernate.annotations.Entity;

/**
 *
 * @author authorName
 */
@Entity
public class Presentation 
{
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Id
    private int id;
    @Temporal(TemporalType.TIMESTAMP)
    private DateTime beginTime;
    @Temporal(TemporalType.TIMESTAMP)
    private DateTime endTime;

    @ManyToOne
    private Location location;
    private int locationId;

    @ManyToMany
    private List<User> users;

    @ManyToMany(mappedBy = "presentations")
    private List<Planning> plannings;

}

The query i am trying to execute:

我试图执行的查询：

Query q = session.createQuery("SELECT p FROM " + Presentation.class.getName() + " p");
presentationModel = new PresentationTableModel((List<Object[]>)q.list());

And this is how i get the session to execute queries

这就是我如何让会话执行查询

Session session = HibernateUtil.getSessionFactory().getCurrentSession();

stacktrace of the error message:

错误消息的堆栈跟踪：

56 [AWT-EventQueue-0] INFO org.hibernate.annotations.common.Version - Hibernate Commons Annotations 3.2.0.Final
59 [AWT-EventQueue-0] INFO org.hibernate.cfg.Environment - Hibernate 3.6.10.Final
60 [AWT-EventQueue-0] INFO org.hibernate.cfg.Environment - hibernate.properties not found
61 [AWT-EventQueue-0] INFO org.hibernate.cfg.Environment - Bytecode provider name : javassist
63 [AWT-EventQueue-0] INFO org.hibernate.cfg.Environment - using JDK 1.4 java.sql.Timestamp handling
93 [AWT-EventQueue-0] INFO org.hibernate.cfg.Configuration - configuring from resource: /hibernate.cfg.xml
93 [AWT-EventQueue-0] INFO org.hibernate.cfg.Configuration - Configuration resource: /hibernate.cfg.xml
123 [AWT-EventQueue-0] WARN org.hibernate.util.DTDEntityResolver - recognized obsolete hibernate namespace http://hibernate.sourceforge.net/. Use namespace http://www.hibernate.org/dtd/ instead. Refer to Hibernate 3.6 Migration Guide!
141 [AWT-EventQueue-0] INFO org.hibernate.cfg.Configuration - Configured SessionFactory: null
167 [AWT-EventQueue-0] INFO org.hibernate.cfg.Configuration - Hibernate Validator not found: ignoring
169 [AWT-EventQueue-0] INFO org.hibernate.cfg.search.HibernateSearchEventListenerRegister - Unable to find org.hibernate.search.event.FullTextIndexEventListener on the classpath. Hibernate Search is not enabled.
171 [AWT-EventQueue-0] INFO org.hibernate.connection.DriverManagerConnectionProvider - Using Hibernate built-in connection pool (not for production use!)
171 [AWT-EventQueue-0] INFO org.hibernate.connection.DriverManagerConnectionProvider - Hibernate connection pool size: 20
171 [AWT-EventQueue-0] INFO org.hibernate.connection.DriverManagerConnectionProvider - autocommit mode: false
175 [AWT-EventQueue-0] INFO org.hibernate.connection.DriverManagerConnectionProvider - using driver: com.mysql.jdbc.Driver at URL: jdbc:mysql://localhost:3306/Projecten2?zeroDateTimeBehavior=convertToNull
175 [AWT-EventQueue-0] INFO org.hibernate.connection.DriverManagerConnectionProvider - connection properties: {user=root, password=****}
340 [AWT-EventQueue-0] INFO org.hibernate.dialect.Dialect - Using dialect: org.hibernate.dialect.MySQLDialect
346 [AWT-EventQueue-0] INFO org.hibernate.cfg.SettingsFactory - Database ->
       name : MySQL
    version : 5.6.14
      major : 5
      minor : 6
347 [AWT-EventQueue-0] INFO org.hibernate.cfg.SettingsFactory - Driver ->
       name : MySQL-AB JDBC Driver
    version : mysql-connector-java-5.1.23 ( Revision: ${bzr.revision-id} )
      major : 5
      minor : 1
347 [AWT-EventQueue-0] INFO org.hibernate.transaction.TransactionFactoryFactory - Using default transaction strategy (direct JDBC transactions)
348 [AWT-EventQueue-0] INFO org.hibernate.transaction.TransactionManagerLookupFactory - No TransactionManagerLookup configured (in JTA environment, use of read-write or transactional second-level cache is not recommended)
348 [AWT-EventQueue-0] INFO org.hibernate.cfg.SettingsFactory - Automatic flush during beforeCompletion(): disabled
348 [AWT-EventQueue-0] INFO org.hibernate.cfg.SettingsFactory - Automatic session close at end of transaction: disabled
348 [AWT-EventQueue-0] INFO org.hibernate.cfg.SettingsFactory - JDBC batch size: 15
348 [AWT-EventQueue-0] INFO org.hibernate.cfg.SettingsFactory - JDBC batch updates for versioned data: disabled
348 [AWT-EventQueue-0] INFO org.hibernate.cfg.SettingsFactory - Scrollable result sets: enabled
348 [AWT-EventQueue-0] INFO org.hibernate.cfg.SettingsFactory - JDBC3 getGeneratedKeys(): enabled
348 [AWT-EventQueue-0] INFO org.hibernate.cfg.SettingsFactory - Connection release mode: auto
348 [AWT-EventQueue-0] INFO org.hibernate.cfg.SettingsFactory - Maximum outer join fetch depth: 2
348 [AWT-EventQueue-0] INFO org.hibernate.cfg.SettingsFactory - Default batch fetch size: 1
348 [AWT-EventQueue-0] INFO org.hibernate.cfg.SettingsFactory - Generate SQL with comments: disabled
348 [AWT-EventQueue-0] INFO org.hibernate.cfg.SettingsFactory - Order SQL updates by primary key: disabled
348 [AWT-EventQueue-0] INFO org.hibernate.cfg.SettingsFactory - Order SQL inserts for batching: disabled
348 [AWT-EventQueue-0] INFO org.hibernate.cfg.SettingsFactory - Query translator: org.hibernate.hql.ast.ASTQueryTranslatorFactory
349 [AWT-EventQueue-0] INFO org.hibernate.hql.ast.ASTQueryTranslatorFactory - Using ASTQueryTranslatorFactory
349 [AWT-EventQueue-0] INFO org.hibernate.cfg.SettingsFactory - Query language substitutions: {}
349 [AWT-EventQueue-0] INFO org.hibernate.cfg.SettingsFactory - JPA-QL strict compliance: disabled
349 [AWT-EventQueue-0] INFO org.hibernate.cfg.SettingsFactory - Second-level cache: enabled
349 [AWT-EventQueue-0] INFO org.hibernate.cfg.SettingsFactory - Query cache: disabled
349 [AWT-EventQueue-0] INFO org.hibernate.cfg.SettingsFactory - Cache region factory : org.hibernate.cache.impl.NoCachingRegionFactory
350 [AWT-EventQueue-0] INFO org.hibernate.cfg.SettingsFactory - Optimize cache for minimal puts: disabled
350 [AWT-EventQueue-0] INFO org.hibernate.cfg.SettingsFactory - Structured second-level cache entries: disabled
353 [AWT-EventQueue-0] INFO org.hibernate.cfg.SettingsFactory - Statistics: disabled
353 [AWT-EventQueue-0] INFO org.hibernate.cfg.SettingsFactory - Deleted entity synthetic identifier rollback: disabled
353 [AWT-EventQueue-0] INFO org.hibernate.cfg.SettingsFactory - Default entity-mode: pojo
353 [AWT-EventQueue-0] INFO org.hibernate.cfg.SettingsFactory - Named query checking : enabled
353 [AWT-EventQueue-0] INFO org.hibernate.cfg.SettingsFactory - Check Nullability in Core (should be disabled when Bean Validation is on): enabled
364 [AWT-EventQueue-0] INFO org.hibernate.impl.SessionFactoryImpl - building session factory
367 [AWT-EventQueue-0] INFO org.hibernate.type.BasicTypeRegistry - Type registration [clob] overrides previous : org.hibernate.type.ClobType@38701425
367 [AWT-EventQueue-0] INFO org.hibernate.type.BasicTypeRegistry - Type registration [java.sql.Clob] overrides previous : org.hibernate.type.ClobType@38701425
367 [AWT-EventQueue-0] INFO org.hibernate.type.BasicTypeRegistry - Type registration [wrapper_characters_clob] overrides previous : org.hibernate.type.CharacterArrayClobType@463aa615
367 [AWT-EventQueue-0] INFO org.hibernate.type.BasicTypeRegistry - Type registration [materialized_clob] overrides previous : org.hibernate.type.MaterializedClobType@346dd0b8
367 [AWT-EventQueue-0] INFO org.hibernate.type.BasicTypeRegistry - Type registration [characters_clob] overrides previous : org.hibernate.type.PrimitiveCharacterArrayClobType@15a1faec
367 [AWT-EventQueue-0] INFO org.hibernate.type.BasicTypeRegistry - Type registration [blob] overrides previous : org.hibernate.type.BlobType@3d60a70c
367 [AWT-EventQueue-0] INFO org.hibernate.type.BasicTypeRegistry - Type registration [java.sql.Blob] overrides previous : org.hibernate.type.BlobType@3d60a70c
367 [AWT-EventQueue-0] INFO org.hibernate.type.BasicTypeRegistry - Type registration [materialized_blob] overrides previous : org.hibernate.type.MaterializedBlobType@1477244f
367 [AWT-EventQueue-0] INFO org.hibernate.type.BasicTypeRegistry - Type registration [wrapper_materialized_blob] overrides previous : org.hibernate.type.WrappedMaterializedBlobType@19f0c908
390 [AWT-EventQueue-0] INFO org.hibernate.impl.SessionFactoryObjectFactory - Not binding factory to JNDI, no JNDI name configured
438 [AWT-EventQueue-0] WARN org.hibernate.hql.QuerySplitter - no persistent classes found for query class: SELECT p FROM entity.Presentation p

I've been searching for quite a bit to fix this but i am not used to using hibernate and i followed their documentation article about mapping but it didn't seem to work.

我一直在寻找很多来解决这个问题，但我不习惯使用休眠，我遵循了他们关于映射的文档文章，但它似乎没有用。

采纳答案by Mikko Maunu

As documented for example here, name of the entity defaults to the simple class name. It does not contain name of the package. In this case name of the entity is Presentation.

作为记录例如这里，实体默认为简单的类名的名称。它不包含包的名称。在这种情况下，实体的名称是Presentation。

Method getNamein java.lang.Class returns also package, so it is not useful in this case. Better ?ethod for this case is getSimpleName():

java.lang.Class 中的方法getName也返回包，所以在这种情况下它没有用。对于这种情况，更好的方法是getSimpleName()：

session.createQuery("SELECT p FROM " + Presentation.class.getSimpleName() + " p");

As a side note, likely there is no reason to use org.hibernate.annotations.Entityinstead of javax.persistence.Entity.

作为旁注，可能没有理由使用org.hibernate.annotations.Entity而不是javax.persistence.Entity。