java.lang.IllegalStateException：没有事务性的EntityManager可用 [英] java.lang.IllegalStateException: No transactional EntityManager available

问题描述

项目使用Hibernate（JPA），Spring和Maven。我的实体和DAO在单独的JAR中。

pom.xml：

 < project ...> 
 ... 
< artifactId>数据库< / artifactId> 
 
<依赖关系> 
< dependency> 
< groupId> org.hibernate< / groupId> 
< artifactId> hibernate-entitymanager< / artifactId> 
< version> 3.5.4-最终< / version> 
< /依赖关系> 
< /依赖关系> 
< / project> 
  

DAO：

  public class AbstractDAO< T extends BaseEntity>实现GenericDAO< T> {
 
 
 private final Class< T>对PersistentClass; 
 
私人EntityManager entityManager; 
 $ b $ public public AbstractDAO（Class< T> entityClass）{
 super（）; 
 this.persistentClass = entityClass; 
} 
 
 @PersistenceContext 
 public void setEntityManager（EntityManager entityManager）{
 this.entityManager = entityManager; 
} 
 
 
 public EntityManager getEntityManager（）{
 return entityManager; 
 
 
 
 $ b public void fooBar（）{
 //此行的异常
 Session session = getEntityManager（） .unwrap（Session.class）; 
 ... 
} 
 
 .... 
  

我有一个使用Spring的模块。

pom.xml：

 < project ...> 
 ... 
< artifactId> api< / artifactId> 
 
<依赖关系> 
< dependency> 
< groupId> org.springframework< / groupId> 
< artifactId> spring-core< / artifactId> 
< version> $ {spring.version}< / version> 
< /依赖关系> 
 
< dependency> 
< groupId> org.springframework< / groupId> 
< artifactId> spring-context< / artifactId> 
< version> $ {spring.version}< / version> 
< /依赖关系> 
 
< dependency> 
< groupId> org.springframework< / groupId> 
< artifactId> spring-orm< / artifactId> 
< version> $ {spring.version}< / version> 
< /依赖关系> 
 .... 
< /依赖关系> 
 
 ... 
< / project> 
  

AppContext.xml：

 < bean id =authServicescope =singletonclass =com.test.management.AuthServiceImpl/> 
 
< bean id =entityManagerFactoryclass =org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBeanname =EntityManagerFactory> 
< property name =persistenceUnitNamevalue =default>< / property> 
< property name =dataSourceref =dataSource>< / property> 
< property name =jpaVendorAdapter> 
< bean class =org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter> 
< property name =showSqlvalue =true/> 
< property name =generateDdlvalue =true/> 
< property name =databasePlatformvalue =$ {db.dialect}/> 
< / bean> 
< / property> 
< / bean> 
 
 <！ - 值在db.properties中定义 - > 
< bean id =dataSourceclass =org.apache.commons.dbcp.BasicDataSourcedestroy-method =close> 
< property name =driverClassNamevalue =$ {db.driver}/> 
< property name =urlvalue =$ {db.url}/> 
< property name =usernamevalue =$ {db.username}/> 
< property name =passwordvalue =$ {db.password}/> 
< / bean> 
 
< bean id =transactionManagerclass =org.springframework.orm.jpa.JpaTransactionManagername =TransactionManager> 
< property name =entityManagerFactoryref =entityManagerFactory>< / property> 
< / bean> 
 
< tx：annotation-driven /> 
 
< bean id =userDAOscope =singletonclass =com.test.database.dao.impl.UserDAOImpl> 
< / bean> 
 
 
< bean class =org.springframework.orm.jpa.support.PersistenceAnnotationBeanPostProcessor/> 
 
< / beans> 
  

服务：

  public class AuthServiceImpl implements AuthService {
 $ b $ @Autowired 
 private UserDAO userDAO; 
 
 
 @Override 
 public void authorization（）{
 userDAO.fooBar（）; 
 
 
 
 
 
 $ b当我试图获得来自EntityManager的会话，我发现了这个异常：
  java.lang.IllegalStateException：没有事务性EntityManager可用
 at org .springframework.orm.jpa.SharedEntityManagerCreator $ SharedEntityManagerInvocationHandler.invoke（SharedEntityManagerCreator.java:223）
 at $ Proxy121.unwrap（Unknown Source）
  
 
 
解决方案
您必须使用@Transactional注解来包围该方法： 
 
 
  @Transactional 
 public void fooBar（）{
 //此行的异常
 Session session = getEntityManager（）。unwrap（Session.class）; 
 ... 
} 
  
并启用spring @Transactional处理在你的spring的xml配置文件中声明下面的代码（txManager是你的管理器的id）。 
 
 
 < tx：annotation-driven transaction-manager =txManager/> 
  
 
Project use Hibernate (JPA), Spring and Maven. My entity and DAO in a separate JAR.


pom.xml:
<project ...>
    ...
    <artifactId>database</artifactId>

    <dependencies>
        <dependency>
            <groupId>org.hibernate</groupId>
            <artifactId>hibernate-entitymanager</artifactId>
            <version>3.5.4-Final</version>
        </dependency>
    </dependencies>    
</project>
DAO:
public class AbstractDAO<T extends BaseEntity> implements GenericDAO<T> {


    private final Class<T> persistentClass;

    private EntityManager entityManager;

    public AbstractDAO(Class<T> entityClass) {
        super();
        this.persistentClass = entityClass;
    }

    @PersistenceContext
    public void setEntityManager(EntityManager entityManager) {
        this.entityManager = entityManager;
    }


    public EntityManager getEntityManager() {
        return entityManager;
    }

    ...

    public void fooBar() {
       //Exception from this line
       Session session = getEntityManager().unwrap(Session.class);
       ...
    }

    ....
}

I have a module, which use Spring.

pom.xml:
<project ...>
...
<artifactId>api</artifactId>

<dependencies>
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-core</artifactId>
        <version>${spring.version}</version>
    </dependency>

    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-context</artifactId>
        <version>${spring.version}</version>
    </dependency>

    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-orm</artifactId>
        <version>${spring.version}</version>
    </dependency>
    ....
</dependencies>

 ...    
</project>
AppContext.xml:
<bean id="authService" scope="singleton" class="com.test.management.AuthServiceImpl" />

    <bean id="entityManagerFactory" class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean" name="EntityManagerFactory">
        <property name="persistenceUnitName" value="default"></property>
        <property name="dataSource" ref="dataSource"></property>
        <property name="jpaVendorAdapter">
            <bean class="org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter">
                <property name="showSql" value="true" />
                <property name="generateDdl" value="true" />
                <property name="databasePlatform" value="${db.dialect}" />
            </bean>
        </property>     
    </bean>

    <!-- Values are defined in db.properties -->
    <bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close">
        <property name="driverClassName" value="${db.driver}" />
        <property name="url" value="${db.url}" />
        <property name="username" value="${db.username}" />
        <property name="password" value="${db.password}" />
    </bean>

    <bean id="transactionManager" class="org.springframework.orm.jpa.JpaTransactionManager" name="TransactionManager">
        <property name="entityManagerFactory" ref="entityManagerFactory"></property>
    </bean>

    <tx:annotation-driven />

    <bean id="userDAO" scope="singleton" class="com.test.database.dao.impl.UserDAOImpl">
    </bean>


    <bean class="org.springframework.orm.jpa.support.PersistenceAnnotationBeanPostProcessor" />

</beans> 
Service:
public class AuthServiceImpl implements AuthService {

    @Autowired
    private UserDAO userDAO;


    @Override
    public void authorization() {
        userDAO.fooBar();

    }
}
When I'm trying to get the session from EntityManager, I catch this exception:
java.lang.IllegalStateException: No transactional EntityManager available
    at org.springframework.orm.jpa.SharedEntityManagerCreator$SharedEntityManagerInvocationHandler.invoke(SharedEntityManagerCreator.java:223)
    at $Proxy121.unwrap(Unknown Source) 

解决方案
You must surround the method with the @Transactional annotation: 
@Transactional
public void fooBar() {
   //Exception from this line
   Session session = getEntityManager().unwrap(Session.class);
   ...
}
And enable the spring @Transactional processing with the following declaration in your spring's xml configuration file (txManager is the id of the your manager).
<tx:annotation-driven transaction-manager="txManager" />


                        
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