Spring 为什么我会得到;“没有可用的事务实体管理器”;关于em.persist(…)?
我有一个SpringMVC项目,正在读/写MySQL数据库 这是我的刀。。。Spring 为什么我会得到;“没有可用的事务实体管理器”;关于em.persist(…)?,spring,spring-mvc,spring-orm,Spring,Spring Mvc,Spring Orm,我有一个SpringMVC项目,正在读/写MySQL数据库 这是我的刀。。。getAll()和getlabbylabbid(…)工作正常 当我执行saveLab(…)时,我在em.persist(lab)上得到这个异常 javax.persistence.TransactionRequiredException: No transactional EntityManager available at org.springframework.orm.jpa.SharedEntityMana
getAll()
和getlabbylabbid(…)
工作正常
当我执行saveLab(…)
时,我在em.persist(lab)
上得到这个异常
javax.persistence.TransactionRequiredException: No transactional EntityManager available
at org.springframework.orm.jpa.SharedEntityManagerCreator$SharedEntityManagerInvocationHandler.invoke(SharedEntityManagerCreator.java:275)
at com.sun.proxy.$Proxy52.persist(Unknown Source)
at com.mycompany.ion.labutil.dao.LabDAOImpl.saveLab(LabDAOImpl.java:29)
at com.mycompany.ion.labutil.service.LabServiceImpl.saveLab(LabServiceImpl.java:52)
at com.mycompany.ion.labutil.controller.LabController.doSaveLab(LabController.java:110)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:497)
at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:221)
at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:137)
at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:110)
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandleMethod(RequestMappingHandlerAdapter.java:777)
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:706)
at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:85)
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:943)
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:877)
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:966)
at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:857)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:622)
at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:842)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:291)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:219)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:106)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:142)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79)
at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:617)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:88)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:518)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1091)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:668)
at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:279)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Thread.java:745)
这是刀
package com.mycompany.ion.labutil.dao;
import java.util.List;
import javax.persistence.EntityManager;
import javax.persistence.PersistenceContext;
import javax.transaction.Transactional;
import org.springframework.stereotype.Repository;
import com.mycompany.ion.labutil.domain.Lab;
@Repository
public class LabDAOImpl implements LabDAO {
@PersistenceContext(unitName = "JpaPersistenceUnit")
private EntityManager em;
public List<Lab> getAll() throws Exception {
return em.createQuery("FROM Lab").getResultList();
}
public Lab getLabByLabId(String labId) throws Exception {
return em.find(Lab.class, labId);
}
@Transactional
public Lab saveLab(Lab lab) throws Exception {
em.persist(lab);
return getLabByLabId(lab.getLab_id());
}
}
我将servlet context.xml
更改为:
<context:component-scan base-package="com.mycompany.myteam.myapp" >
<context:exclude-filter type="annotation" expression="org.springframework.stereotype.Controller"/>
</context:component-scan>
<context:component-scan base-package="com.mycompany.myteam.myapp.mycontrollers" />
谢谢malejpavouk 2个不同的上下文。Root是父上下文,dispatcher是子上下文。子(web)上下文应仅包含周界/www(控制器)的bean。 机制是子上下文从父上下文看到所有内容,但父上下文确实从子上下文看到bean。) 您可以在子上下文中扫描整个应用程序。所以我的猜测是tx:annotation-driven将只使用直接包含在给定上下文中的工具bean(而不是那些仅可见的工具bean)。
所以要进行两次扫描,一次扫描子/调度程序上下文中的控制器,第二次扫描父/根目录中的所有公共bean 让我猜猜。。。您还有另一个
*context.xml
,它还包含上下文:组件扫描
。。。请添加完整的堆栈跟踪,而不是代码片段。最有趣的信息是在堆栈跟踪的末尾,而不是顶部。@M.Deinum嗨,我在上面添加了完整的堆栈跟踪,是的,看起来有两个*context.xml文件。。。我把它们都包括在上面/webapp/WEB-INF/spring/root-context.xml
。。和/webapp/WEB-INF/spring/appservlet/servlet context.xml
。。。是的,有两个上下文:组件扫描部分。你很在行!我该怎么做才能修复它呢?进行大约14年的spring开发有助于:)。禁用servlet context.xml中的默认过滤器,并仅使用包含过滤器扫描@Controllers
。(您可能希望在根上下文中排除对@Controllers
的扫描).@M.Deinum Thx以获取帮助。我需要更多的人手。因此我(a)从servlet上下文
中删除上下文:组件扫描
部分;和(b)在根上下文中的上下文:组件扫描中添加正确的包含。是这样吗?不知道如何做第(b)部分。。。你有一个例子吗?没有,你留下两个,一个扫描除@Controller
以外的所有内容,另一个只扫描@Controller
。谢谢你的帮助!终于,我回到了这个问题上,用你的建议解决了它。
<?xml version="1.0" encoding="UTF-8"?>
<beans:beans xmlns="http://www.springframework.org/schema/mvc"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:beans="http://www.springframework.org/schema/beans"
xmlns:context="http://www.springframework.org/schema/context"
xsi:schemaLocation="http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc.xsd
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.xsd">
<!-- DispatcherServlet Context: defines this servlet's request-processing infrastructure -->
<!-- Enables the Spring MVC @Controller programming model -->
<annotation-driven />
<!-- Handles HTTP GET requests for /resources/** by efficiently serving up static resources in the ${webappRoot}/resources directory -->
<resources mapping="/resources/**" location="/resources/" />
<!-- Resolves views selected for rendering by @Controllers to .jsp resources in the /WEB-INF/views directory -->
<beans:bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<beans:property name="prefix" value="/WEB-INF/views/" />
<beans:property name="suffix" value=".jsp" />
</beans:bean>
<context:component-scan base-package="com.mycompany.ion" />
</beans:beans>
<context:component-scan base-package="com.mycompany.myteam.myapp" >
<context:exclude-filter type="annotation" expression="org.springframework.stereotype.Controller"/>
</context:component-scan>
<context:component-scan base-package="com.mycompany.myteam.myapp.mycontrollers" />