[英]Request processing failed; nested exception is javax.persistence.TransactionRequiredException: No transactional EntityManager available
An exception occurs while I'm trying to persist an object. 当我尝试保留对象时发生异常。
import org.springframework.transaction.annotation.Transactional;
@Repository("DBRepository")
@Transactional
public class DBRepository implements Repository {
@PersistenceContext
private EntityManager entityManager;
@Override
public void addElement(Element element) {
logger.debug("Element {} is going to be added to database", element);
entityManager.persist(element);
}
}
persistence.xml persistence.xml
<?xml version="1.0" encoding="UTF-8"?>
<persistence xmlns="http://java.sun.com/xml/ns/persistence"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/persistence http://java.sun.com/xml/ns/persistence/persistence_2_0.xsd"
version="2.0">
<persistence-unit name="p_unit" transaction-type="RESOURCE_LOCAL"/>
</persistence>
web.xml web.xml
<context-param>
<param-name>contextConfigLocation</param-name>
<param-value>/WEB-INF/config/jpa-config.xml</param-value>
</context-param>
<listener>
<listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
</listener>
jpa-config.xml jpa-config.xml
<?xml version="1.0" encoding="UTF-8"?>
<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.xsd
http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.0.xsd
http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.2.xsd">
<!-- Using annotation to configure application -->
<context:annotation-config/>
<context:component-scan base-package="web.tmh"/>
<!-- Tells Spring to use persistence context annotation -->
<bean class="org.springframework.orm.jpa.support.PersistenceAnnotationBeanPostProcessor"/>
<tx:annotation-driven mode="proxy" transaction-manager="transactionManager"/>
<bean id="transactionManager" class="org.springframework.orm.jpa.JpaTransactionManager">
<property name="entityManagerFactory" ref="entityManagerFactory"/>
</bean>
<bean id="entityManagerFactory" class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
<property name="persistenceUnitName" value="p_unit"/>
<property name="dataSource" ref="dataSource"/>
<property name="jpaVendorAdapter">
<bean class="org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter">
<property name="showSql" value="true"/>
</bean>
</property>
<property name="jpaPropertyMap">
<map>
<entry key="hibernate.dialect" value="org.hibernate.dialect.MySQL5InnoDBDialect"/>
<entry key="hibernate.hbm2ddl.auto" value="update"/>
</map>
</property>
</bean>
<bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
<property name="driverClassName" value="com.mysql.jdbc.Driver"/>
<!-- autoReconnect=true param allows our application to reconnect to base if connection was lost -->
<property name="url" value="jdbc:mysql://localhost:3306/TellMeHow?autoReconnect=true"/>
<property name="username" value="root"/>
<property name="password" value="root"/>
</bean>
</beans>
So as you can see I used right Transactional annotation, and have <tx:annotation-driven mode="proxy" transaction-manager="transactionManager"/>
in my jpa-config.xml. 因此,您可以看到我使用了正确的Transactional批注,并且在jpa-config.xml中具有
<tx:annotation-driven mode="proxy" transaction-manager="transactionManager"/>
。 So I don't really understand why it doesn't want do work 所以我真的不明白为什么它不想要工作
Ok, the problem was solved. 好的,问题解决了。 I've made a small mistake in my
dispatcher-config.xml
: 我在
dispatcher-config.xml
犯了一个小错误:
So instead of 所以代替
<mvc:annotation-driven/>
<context:component-scan base-package="web.tmh"/>
I had to write 我不得不写
<mvc:annotation-driven/>
<context:component-scan base-package="web.tmh.controller"/>
I thought that component-scan
worked recursively, but seems like it didn't... 我以为
component-scan
递归地工作,但似乎没有...
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