Spring - 没有可用于当前线程的实际事务的 EntityManager - 无法可靠地处理“持久"调用 [英] Spring - No EntityManager with actual transaction available for current thread - cannot reliably process 'persist' call
问题描述
在 Spring MVC Web 应用程序中尝试调用persist"方法将实体模型保存到数据库时出现此错误.无法在互联网上真正找到与此特定错误相关的任何帖子或页面.EntityManagerFactory bean 似乎有问题,但我对 Spring 编程还很陌生,所以对我来说,似乎一切都初始化得很好,并且根据网络中的各种教程文章.
I get this error when trying to invoke "persist" method to save entity model to database in my Spring MVC web application. Can't really find any post or page in internet that can relate to this particular error. It seems like something's wrong with EntityManagerFactory bean but i'm fairly new to Spring programming so for me it seems like everything is initialized fine and according to various tutorial articles in web.
dispatcher-servlet.xml
dispatcher-servlet.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:mvc="http://www.springframework.org/schema/mvc"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:jpa="http://www.springframework.org/schema/data/jpa"
xsi:schemaLocation="
http://www.springframework.org/schema/mvc
http://www.springframework.org/schema/mvc/spring-mvc-4.0.xsd
http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-4.0.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context-4.0.xsd
http://www.springframework.org/schema/jdbc
http://www.springframework.org/schema/jdbc/spring-jdbc-3.2.xsd
http://www.springframework.org/schema/data/jpa
http://www.springframework.org/schema/data/jpa/spring-jpa-1.3.xsd
http://www.springframework.org/schema/data/repository
http://www.springframework.org/schema/data/repository/spring-repository-1.5.xsd
http://www.springframework.org/schema/jee
http://www.springframework.org/schema/jee/spring-jee-3.2.xsd">
<context:component-scan base-package="wymysl.Controllers" />
<jpa:repositories base-package="wymysl.repositories"/>
<context:component-scan base-package="wymysl.beans" />
<context:component-scan base-package="wymysl.Validators" />
<bean
class="org.springframework.orm.jpa.support.PersistenceAnnotationBeanPostProcessor" />
<bean class="org.springframework.orm.hibernate4.HibernateExceptionTranslator"/>
<bean id="passwordValidator" class="wymysl.Validators.PasswordValidator"></bean>
<bean id="dataSource"
class="org.springframework.jdbc.datasource.DriverManagerDataSource">
<property name="driverClassName" value="oracle.jdbc.driver.OracleDriver" />
<property name="url" value="jdbc:oracle:thin:@localhost:1521:xe" />
<property name="username" value="system" />
<property name="password" value="polskabieda1" />
</bean>
<bean id="entityManagerFactory" class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
<property name="persistenceXmlLocation" value="classpath:./META-INF/persistence.xml" />
<property name="dataSource" ref="dataSource" />
<property name="jpaVendorAdapter">
<bean class="org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter">
<property name="databasePlatform" value="org.hibernate.dialect.H2Dialect" />
<property name="showSql" value="true" />
<property name="generateDdl" value="false" />
</bean>
</property>
<property name="jpaProperties">
<props>
<prop key="hibernate.max_fetch_depth">3</prop>
<prop key="hibernate.jdbc.fetch_size">50</prop>
<prop key="hibernate.jdbc.batch_size">10</prop>
</props>
</property>
</bean>
<mvc:annotation-driven />
<bean id="messageSource" class="org.springframework.context.support.ReloadableResourceBundleMessageSource">
<property name="basename" value="classpath:messages" />
</bean>
<bean name="transactionManager" class="org.springframework.orm.jpa.JpaTransactionManager">
<property name="entityManagerFactory" ref="entityManagerFactory"/>
</bean>
<bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<property name="prefix">
<value>/WEB-INF/jsp/</value>
</property>
<property name="suffix">
<value>.jsp</value>
</property>
</bean>
<mvc:resources mapping="/resources/**" location="/resources/" />
<mvc:resources mapping="/resources/*" location="/resources/css/"
cache-period="31556926"/>
</beans>
注册控制器.java
@Controller
public class RegisterController {
@PersistenceContext
EntityManager entityManager;
@Autowired
PasswordValidator passwordValidator;
@InitBinder
private void initBinder(WebDataBinder binder) {
binder.setValidator(passwordValidator);
}
@RequestMapping(value = "/addUser", method = RequestMethod.GET)
public String register(Person person) {
return "register";
}
@RequestMapping(value = "/addUser", method = RequestMethod.POST)
public String register(@ModelAttribute("person") @Valid @Validated Person person, BindingResult result) {
if(result.hasErrors()) {
return "register";
} else {
entityManager.persist(person);
return "index";
}
}
推荐答案
我遇到了同样的问题,我将该方法注释为 @Transactional
并且它起作用了.
I had the same problem and I annotated the method as @Transactional
and it worked.
更新:检查 spring 文档,默认情况下 PersistenceContext 的类型是事务,所以这就是方法必须是事务性的(http://docs.spring.io/spring/docs/current/spring-framework-reference/html/orm.html):
UPDATE: checking the spring documentation it looks like by default the PersistenceContext is of type Transaction, so that's why the method has to be transactional (http://docs.spring.io/spring/docs/current/spring-framework-reference/html/orm.html):
@PersistenceContext 注解有一个可选的属性类型,默认为 PersistenceContextType.TRANSACTION.这个默认是接收共享 EntityManager 代理需要什么.这替代方案,PersistenceContextType.EXTENDED,是一个完全不同的事情:这导致了所谓的扩展 EntityManager,这不是线程安全的,因此不能同时使用访问组件,例如 Spring 管理的单例 bean.扩展EntityManagers 只应该用在有状态的组件中例如,驻留在会话中,具有生命周期EntityManager 与当前事务无关,而是与当前事务相关联完全取决于应用程序.
The @PersistenceContext annotation has an optional attribute type, which defaults to PersistenceContextType.TRANSACTION. This default is what you need to receive a shared EntityManager proxy. The alternative, PersistenceContextType.EXTENDED, is a completely different affair: This results in a so-called extended EntityManager, which is not thread-safe and hence must not be used in a concurrently accessed component such as a Spring-managed singleton bean. Extended EntityManagers are only supposed to be used in stateful components that, for example, reside in a session, with the lifecycle of the EntityManager not tied to a current transaction but rather being completely up to the application.
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