您好我面临以下问题：我有一个带有以下配置文件的 spring mvc 应用程序。有两个单独的 spring 配置文件，一个用于 jpa，一个用于 spring mvc 问题是当我尝试在数据库中保留某些内容时出现错误：
消息请求处理失败；嵌套异常是 javax.persistence.TransactionRequiredException: No EntityManager with actual transaction available for current thread - 无法可靠地处理“持久”调用
（我在服务类上有@Transactional）如果我将 jpaConfig.xml 移动到 servlet-config.xml 应用程序工作正常。我不知道为什么会发生这种情况，并且我发现将此标签移动到 mvc 配置文件是错误的。你能帮我理解为什么会这样吗？
Web.xml：
<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee
http://xmlns.jcp.org/xml/ns/javaee/web-app_4_0.xsd"
version="4.0">
<context-param>
<param-name>contextConfigLocation</param-name>
<param-value>classpath:jpaContext.xml</param-value>
</context-param>
<listener>
<listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
</listener>
<servlet>
<servlet-name>fitTrackerServlet</servlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
<init-param>
<param-name>contextConfigLocation</param-name>
<param-value>/WEB-INF/config/servlet-config.xml</param-value>
</init-param>
<load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name>fitTrackerServlet</servlet-name>
<url-pattern>/app/*</url-pattern>
</servlet-mapping>
<servlet-mapping>
<servlet-name>fitTrackerServlet</servlet-name>
<url-pattern>/pdfs/**</url-pattern>
</servlet-mapping>
servlet-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:context="http://www.springframework.org/schema/context"
xmlns:mvc="http://www.springframework.org/schema/mvc"
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.xsd
http://www.springframework.org/schema/mvc
http://www.springframework.org/schema/mvc/spring-mvc.xsd">
<mvc:annotation-driven/>
<context:component-scan base-package="com.example"/>
<mvc:interceptors>
<bean class="org.springframework.web.servlet.i18n.LocaleChangeInterceptor">
<property name="paramName" value="language"/>
</bean>
</mvc:interceptors>
<mvc:resources mapping="pdfs" location="/pdfs/**"/>
<bean class="org.springframework.web.servlet.view.ContentNegotiatingViewResolver" >
<property name="order" value="1" />
<property name="contentNegotiationManager" >
<bean class="org.springframework.web.accept.ContentNegotiationManager">
<constructor-arg>
<bean class="org.springframework.web.accept.PathExtensionContentNegotiationStrategy" >
<constructor-arg>
<map>
<entry key="json" value="application/json" />
<entry key="xml" value="application/xml" />
</map>
</constructor-arg>
</bean>
</constructor-arg>
</bean>
</property>
<property name="defaultViews">
<list>
<bean class="org.springframework.web.servlet.view.json.MappingJackson2JsonView" />
<bean class="org.springframework.web.servlet.view.xml.MarshallingView" >
<constructor-arg>
<bean class="org.springframework.oxm.jaxb.Jaxb2Marshaller">
<property name="classesToBeBound">
<list>
<value>com.example.domain.Activity</value>
</list>
</property>
</bean>
</constructor-arg>
</bean>
</list>
</property>
</bean>
<bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<property name="prefix" value="/WEB-INF/jsp/"/>
<property name="suffix" value=".jsp"/>
<property name="order" value="2" />
</bean>
<bean id="messageSource" class="org.springframework.context.support.ResourceBundleMessageSource">
<property name="basename" value="messages"/>
</bean>
<bean id="localeResolver" class="org.springframework.web.servlet.i18n.SessionLocaleResolver">
<property name="defaultLocale" value="en"/>
</bean>
和 jpaContext.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"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx.xsd">
<bean id="entityManagerFactoryBean" class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
<property name="dataSource" ref="dataSource"/>
<property name="packagesToScan" value="com.example.domain"/>
<property name="jpaVendorAdapter">
<bean class="org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter"/>
</property>
<property name="jpaProperties">
<props>
<prop key="hibernate.hbm2ddl.auto">create</prop>
<prop key="hibernate.dialect">org.hibernate.dialect.MySQL5Dialect</prop>
</props>
</property>
</bean>
<bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
<property name="driverClassName" value="com.mysql.jdbc.Driver"/>
<property name="url" value="jdbc:mysql://localhost:3306/fitness_tracker?autoReconnect=true"/>
<property name="username" value="root"/>
<property name="password" value="password"/>
</bean>
<bean id="transactionManager" class="org.springframework.orm.jpa.JpaTransactionManager">
<property name="entityManagerFactory" ref="entityManagerFactoryBean"/>
</bean>
<tx:annotation-driven/>
道：
@Repository
public class GoalRepositoryImpl implements GoalRepository {
@PersistenceContext
private EntityManager em;
@Override
@Transactional
public Goal save(Goal goal) {
em.persist(goal);
em.flush();
return goal;
}
}