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

Posted 2023-02-26

【中文标题】休眠：没有找到查询类的持久类：SELECT p FROM entity.Presentation p

【英文标题】：Hibernate: no persistent classes found for query class: SELECT p FROM entity.Presentation p

【发布时间】：2014-04-02 16:34:27

【问题描述】：

我正在尝试坚持我的课程，但它总是抛出这个错误。

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>

这就是我要坚持的课程

/*
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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;

我正在尝试执行的查询：

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

这就是我让会话执行查询的方式

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

错误信息的堆栈跟踪：

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

我一直在寻找解决这个问题的方法，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。

【问题讨论】：

粘贴异常的准确和完整的堆栈跟踪。请注意，这样的查询返回 List<Presentation>，而不是 List<Object[]>。

我添加了堆栈跟踪，我将其更改为 List 但结果保持不变

【参考方案1】：

如 here 所记录的，实体的名称默认为简单的类名称。它不包含包的名称。在这种情况下，实体的名称是 Presentation。

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

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

附带说明，可能没有理由使用 org.hibernate.annotations.Entity 代替 javax.persistence.Entity。

【讨论】：

实际上，您的旁注是问题的真正答案：该类不是实体，因为它没有使用 javax.persistence.Entity 进行注释。使用完全限定名称不是强制性的，但它是允许的并且可以正常工作。

这确实解决了 :) 感谢您的帮助和详细解释的信息

@JBNizet 你能详细说明一下吗？ “它没有用 javax.persistence.Entity 注释”是什么意思？这是否意味着他应该做类似@Entity(name="full.package.name.with.class.name") 这样的事情才能使用class.getName()？

@Pere 不，我的意思是 OP 使用了注释 org.hibernate.annotations.Entity，而不是 javax.persistence.Entity，这就是他出错并问这个的真正原因题。这不仅仅是一个旁注。这是答案中最重要的部分。