Could not open JPA EntityManager for transaction; nested exception is javax.pers

Spring MVC + JPA(Hibernate) + Mysql, Tomcat 运行一段时间就会出现数据库连接有问题导致系统不能正常使用，报错
Could not open JPA EntityManager for transaction; nested exception is javax.persistence.PersistenceException: org.hibernate.TransactionException: JDBC begin transaction failed

配置文件如下：

web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee"
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" version="2.5">

<display-name>Zanwo Web Application</display-name>

<filter>
<filter-name>CharacterEncodingFilter</filter-name>
<filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>
<init-param>
<param-name>encoding</param-name>
<param-value>utf-8</param-value>
</init-param>
</filter>
<filter-mapping>
<filter-name>CharacterEncodingFilter</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>

<servlet>
<servlet-name>zanwo</servlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
<load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name>zanwo</servlet-name>
<url-pattern>/</url-pattern>
</servlet-mapping>

<welcome-file-list>
<welcome-file>index.html</welcome-file>
</welcome-file-list>
</web-app>
---------------------------------------------------------------------------------------------------------------------------------------------

xxxx-sevlet.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:p="http://www.springframework.org/schema/p" 
xmlns:mvc="http://www.springframework.org/schema/mvc" 
xmlns:context="http://www.springframework.org/schema/context"
xmlns:util="http://www.springframework.org/schema/util" 
xmlns:tx="http://www.springframework.org/schema/tx"
xsi:schemaLocation="http://www.springframework.org/schema/beans 
http://www.springframework.org/schema/beans/spring-beans-3.0.xsd  
            http://www.springframework.org/schema/context 
            http://www.springframework.org/schema/context/spring-context-3.0.xsd  
            http://www.springframework.org/schema/mvc 
            http://www.springframework.org/schema/mvc/spring-mvc-3.0.xsd              
            http://www.springframework.org/schema/util 
            http://www.springframework.org/schema/util/spring-util-3.0.xsd
            http://www.springframework.org/schema/tx 
     http://www.springframework.org/schema/tx/spring-tx.xsd">

<context:annotation-config />

<!-- active @Controller mode -->
<mvc:annotation-driven/>

<!-- static resource begin -->
<mvc:default-servlet-handler />
<mvc:resources mapping="/images/**" location="/images/" />
<mvc:resources mapping="/js/**" location="/js/"/>
<mvc:resources mapping="/css/**" location="/css/"/>
<!-- static resource end -->

<context:component-scan base-package="com.zanwo" />

<!-- transaction begin -->
<bean id="entityManagerFactory" class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
<property name="persistenceUnitName" value="zanwoPU" />
<property name="persistenceXmlLocation" value="classpath:META-INF/persistence.xml"></property>
</bean>
<bean id="transactionManager" class="org.springframework.orm.jpa.JpaTransactionManager">
<property name="entityManagerFactory" ref="entityManagerFactory" />
</bean>
<tx:annotation-driven transaction-manager="transactionManager" />
<!-- transaction end -->

<!-- for Ajax begin -->
<bean class="org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter"/>
<!-- for Ajax end -->

<!-- for message resource begin -->
<bean id="messageSource" class="org.springframework.context.support.ReloadableResourceBundleMessageSource">
<property name="basename" value="classpath:i18n/messages" />
<property name="defaultEncoding" value="UTF-8" />
</bean>
<!-- for message resource end -->

<!-- for upload begin -->
<bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver">  
        <property name="maxUploadSize" value="800000"/>  
    </bean>
<bean id="exceptionResolver" class="org.springframework.web.servlet.handler.SimpleMappingExceptionResolver">
<property name="exceptionMappings">
<props>
<prop key="org.springframework.web.multipart.MaxUploadSizeExceededException">error</prop>
</props>
</property>
</bean>
<!-- for upload end -->

<bean id="viewResolver" class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<property name="prefix">
<value>/WEB-INF/pages/</value>
</property>
<property name="suffix">
<value>.jsp</value>
</property>
</bean>

</beans>

---------------------------------------------------------------------------------------------------------------------------------------------
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_1_0.xsd"
version="1.0">

<persistence-unit name="zanwoPU" transaction-type="RESOURCE_LOCAL">
<provider>org.hibernate.ejb.HibernatePersistence</provider>
<properties>
<property name="hibernate.connection.driver_class" value="com.mysql.jdbc.Driver" />
<property name="hibernate.connection.url" value="jdbc:mysql://localhost:3306/zanwo" />
<property name="hibernate.connection.username" value="zanwo" />
<property name="hibernate.connection.password" value="zanwo888" />
<property name="hibernate.show_sql" value="true" />
<property name="hibernate.format_sql" value="false" />
<property name="hibernate.hbm2ddl.auto" value="update" />
</properties>
</persistence-unit>

</persistence>

2 个解决方案

#1

数据库相应字段有 null 值？

#2

jdbc 连接数据库默认时长为6小时。长时间不访问数据库 会发现JDBC 连接中断。
方案一：设置连接属性为autoReconnect=true；
方案二：写个定时器 没六小时去 访问下数据库（访问数据库任何表）；
希望能够帮到你。