Hibernate org.hibernate.LazyInitializationException：未能延迟初始化角色集合： [英] Hibernate org.hibernate.LazyInitializationException: failed to lazily initialize a collection of role:

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问题描述

我有下面提到的实体类，当我执行我的应用程序时，我收到以下异常。一些其他类似的问题没有解决问题。

 警告：StandardWrapperValve [jersey-serlvet]：PWC1406：Servlet。 service（）
对于servlet jersey-serlvet抛出异常
 org.hibernate.LazyInitializationException：未能懒惰地初始化
a集合中的角色：test.entity.Dept.empDeptno，没有会话
或者会话在org.hibernate.collection.internal.AbstractPersistentCollection处关闭了
。 
 throwLazyInitializationException（AbstractPersistentCollection.java:393）$ or $ $ b $ org.hibernate.collection.internal.AbstractPersistentCollection。 
 throwLazyInitializationExceptionIfNotConnected 
（AbstractPersistentCollection.java:385）
位于org.hibernate.collection.internal.AbstractPersistentCollection。 
 initialize（AbstractPersistentCollection.java:378）

我该如何解决这个问题？ p>

雇主实体 

  @Entity 
 @Table（name =EMP，schema =SCOTT
）
 @XmlRootElement 
 @NamedQueries（{
 @NamedQuery（name =Emp.findAllEmployees， query =select e from emp e left 
 join fetch e.deptNo order by e.empno desc）
}）
 public class Emp implements java.io.Serializable {
 @I $ 
 @Column（name =EMPNO，unique = true，nullable = false，precision = 4，
 scale = 0）
 private short empno; 
 @ManyToOne 
 @JoinColumn（name =DEPTNO，referencedColumnName =DEPTNO）
 private Dept deptNo;

部门实体 

  @Entity 
 @Table（name =DEPT，schema =SCOTT
）
 @XmlRootElement 
 public class Dept实现java.io.Serializable {
 @Id 
 @Column（name =DEPTNO，unique = true，nullable = false，precision = 2，
 scale = 0）
私人短的deptno; 
 @OneToMany（fetch = FetchType.LAZY，mappedBy =deptNo）
 private Set< Emp> empDeptno;

DAOImpl 

  @Override 
 public List< Emp> findAllEmployees（）{
 return getEntityManager（）。createNamedQuery（Emp.findAllEmployees，
 Emp.class）.getResultList（）; 
}

泽西RESTful服务 

  @Component 
 @Path（/ employee）
 public class EmployeeRestService {
 
 @Autowired 
 EmployeeService employeeService; 
 
 @GET 
 @Produces（{MediaType.APPLICATION_JSON}）
 public List< Emp> getEmployees（）{
 List< Emp> emp = new ArrayList< Emp>（）; 
 emp.addAll（getEmployeeService（）。findAllEmployees（））; 
 return emp;

Spring applicationContext.xml 

 < beans xmlns =http://www.springframework.org/schema/beans
 xmlns：xsi =http： //www.w3.org/2001/XMLSchema-instancexmlns：tx =http://www.springframework.org/schema/tx
 xmlns：context =http：//www.springframework。 org / schema / context
 xsi：schemaLocation =http://www.springframework.org/schema/beans 
 http://www.springframework.org/schema/beans/spring-beans- 3.0.xsd 
 http://www.springframework.org/schema/tx 
 http://www.springframework.org/schema/tx/spring-tx-3.0.xsd 
 http ：//www.springframework.org/schema/context 
 http://www.springframework.org/schema/context/spring-context-3.0.xsd
> 
 <！ - 数据源声明 - > 
< bean id =DataSourceclass =org.springframework.jndi.JndiObjectFactoryBean> 
< property name =jndiNamevalue =jdbc / scottDS/> 
< / bean> 
 
< context：component-scan base-package =net.test/> 
< bean class =org.springframework.dao.annotation.PersistenceExceptionTranslationPostProcessor/> 
< bean id =entityManagerFactory
 class =org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean> 
< property name =dataSourceref =DataSource/> 
< property name =packagesToScanvalue =net.test/> 
< property name =jpaVendorAdapter> 
< bean class =org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter> 
< property name =showSqlvalue =false/> 
< property name =generateDdlvalue =false/> 
< property name =databasePlatformvalue =$ {jdbc.dialectClass}/> 
< / bean> 
< / property> 
< / bean> 
< bean id =defaultLobHandlerclass =org.springframework.jdbc.support.lob.DefaultLobHandler/> 
<！ - 交易配置 - > 
< bean id =transactionManagerclass =org.springframework.orm.jpa.JpaTransactionManager> 
< property name =entityManagerFactoryref =entityManagerFactory/> 
< / bean> 
< tx：注解驱动的事务管理器=transactionManager/> 
< context：annotation-config /> 
< bean id =hibernateStatisticsMBeanclass =org.hibernate.jmx.StatisticsService> 
< property name =statisticsEnabledvalue =true/> 
< property name =sessionFactoryvalue =＃{entityManagerFactory.sessionFactory}/> 
< / bean> 
< / beans>


解决方案

.xml 

 < filter> 
< filter-name> OpenEntityManagerInViewFilter< / filter-name> 
< filter-class> org.springframework.orm.jpa.support.OpenEntityManagerInViewFilter< / filter-class> 
< / filter> 
< filter-mapping> 
< filter-name> OpenEntityManagerInViewFilter< / filter-name> 
< url-pattern> / *< / url-pattern> 
< / filter-mapping>

礼貌这里和这里



谢谢


I have the below mentioned Entity classes, when I execute my application I am getting the following exception. Some of the other similar questions didn't solve the problem.

WARNING: StandardWrapperValve[jersey-serlvet]: PWC1406: Servlet.service()
for servlet jersey-serlvet threw exception
org.hibernate.LazyInitializationException: failed to lazily initialize 
a collection of role: test.entity.Dept.empDeptno, no session
or session was closed
at org.hibernate.collection.internal.AbstractPersistentCollection.
throwLazyInitializationException(AbstractPersistentCollection.java:393)
       at    org.hibernate.collection.internal.AbstractPersistentCollection.
throwLazyInitializationExceptionIfNotConnected
(AbstractPersistentCollection.java:385)
    at org.hibernate.collection.internal.AbstractPersistentCollection.
initialize(AbstractPersistentCollection.java:378)

How can I solve this issue?

Emp Entity

@Entity
@Table(name = "EMP", schema = "SCOTT"
)
@XmlRootElement
@NamedQueries({
    @NamedQuery(name = "Emp.findAllEmployees", query = "select e from Emp e left 
    join fetch e.deptNo order by e.empno desc")
})
public class Emp implements java.io.Serializable {
@Id
@Column(name = "EMPNO", unique = true, nullable = false, precision = 4,
scale = 0)
private short empno;
@ManyToOne
@JoinColumn(name = "DEPTNO", referencedColumnName = "DEPTNO")
private Dept deptNo;

Dept Entity

@Entity
@Table(name = "DEPT", schema = "SCOTT"
)
@XmlRootElement
public class Dept implements java.io.Serializable {
@Id
@Column(name = "DEPTNO", unique = true, nullable = false, precision = 2,
scale = 0)
private short deptno;
@OneToMany(fetch=FetchType.LAZY,mappedBy = "deptNo")
private Set<Emp> empDeptno;

DAOImpl

@Override
public List<Emp> findAllEmployees() {
  return getEntityManager().createNamedQuery("Emp.findAllEmployees",
 Emp.class).getResultList();
}

Jersey RESTful service

 @Component
 @Path("/employee")
 public class EmployeeRestService {

 @Autowired
 EmployeeService employeeService;

 @GET
 @Produces({MediaType.APPLICATION_JSON})
 public List<Emp> getEmployees() {
 List<Emp> emp = new ArrayList<Emp>();
 emp.addAll(getEmployeeService().findAllEmployees());
 return emp;
 }

Spring applicationContext.xml

<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:tx="http://www.springframework.org/schema/tx"
       xmlns:context="http://www.springframework.org/schema/context"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
http://www.springframework.org/schema/tx
http://www.springframework.org/schema/tx/spring-tx-3.0.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context-3.0.xsd"
>
    <!-- Data Source Declaration -->    
    <bean id="DataSource" class="org.springframework.jndi.JndiObjectFactoryBean">
        <property name="jndiName" value="jdbc/scottDS"/>   
    </bean>

    <context:component-scan base-package="net.test" />
    <bean class="org.springframework.dao.annotation.PersistenceExceptionTranslationPostProcessor"/>
    <bean id="entityManagerFactory"
          class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
        <property name="dataSource" ref="DataSource" />
        <property name="packagesToScan" value="net.test" />
        <property name="jpaVendorAdapter">
            <bean class="org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter">
                <property name="showSql" value="false" />
                <property name="generateDdl" value="false" />
                <property name="databasePlatform" value="${jdbc.dialectClass}" />
            </bean>
        </property>
    </bean>
    <bean id="defaultLobHandler" class="org.springframework.jdbc.support.lob.DefaultLobHandler" />  
    <!-- Transaction Config -->
    <bean id="transactionManager" class="org.springframework.orm.jpa.JpaTransactionManager">
        <property name="entityManagerFactory" ref="entityManagerFactory" />
    </bean>
    <tx:annotation-driven transaction-manager="transactionManager"/>          
    <context:annotation-config/>
    <bean id="hibernateStatisticsMBean" class="org.hibernate.jmx.StatisticsService">
        <property name="statisticsEnabled" value="true" />
        <property name="sessionFactory" value="#{entityManagerFactory.sessionFactory}" />
    </bean>
</beans>

解决方案

I have resolved the issue by adding the following in web.xml

<filter>
<filter-name>OpenEntityManagerInViewFilter</filter-name>
<filter-class>org.springframework.orm.jpa.support.OpenEntityManagerInViewFilter</filter-class>
</filter>
<filter-mapping>
<filter-name>OpenEntityManagerInViewFilter</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>

courtesy here and here

Thanks

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