Question

我在互联网上读过这么多关于这个问题的文章，但似乎没有一个明确的解决方案。请有人给我一个明确的答案，为什么我得到数据库超时。该应用程序是一个GWT应用程序，托管在Tomcat 5.5服务器上。我使用spring，会话工厂在applicationContext.xml中创建，如下所示

<bean id="sessionFactory"
      class="org.springframework.orm.hibernate3.annotation.AnnotationSessionFactoryBean">
    <property name="hibernateProperties">
        <props>
            <prop key="hibernate.dialect">${connection.dialect}</prop>
            <prop key="hibernate.connection.username">${connection.username}</prop>
            <prop key="hibernate.connection.password">${connection.password}</prop>
            <prop key="hibernate.connection.url">${connection.url}</prop>
            <prop key="hibernate.connection.driver_class">${connection.driver.class}</prop>
            <prop key="hibernate.show_sql">${show.sql}</prop>
            <prop key="hibernate.hbm2ddl.auto">update</prop>
            <prop key="hibernate.c3p0.min_size">5</prop>
            <prop key="hibernate.c3p0.max_size">20</prop>
            <prop key="hibernate.c3p0.timeout">1800</prop>
            <prop key="hibernate.c3p0.max_statements">50</prop>
            <prop key="hibernate.c3p0.idle_test_period">300</prop>
        </props>
    </property>
    <property name="annotatedClasses">
        <list>
            <value>za.co.xxxx.traintrack.server.model.Answer</value>
            <value>za.co.xxxx.traintrack.server.model.Company</value>
            <value>za.co.xxxx.traintrack.server.model.CompanyRegion</value>
            <value>za.co.xxxx.traintrack.server.model.Merchant</value>
            <value>za.co.xxxx.traintrack.server.model.Module</value>
            <value>za.co.xxxx.traintrack.server.model.Question</value>
            <value>za.co.xxxx.traintrack.server.model.User</value>
            <value>za.co.xxxx.traintrack.server.model.CompletedModule</value>
        </list>
    </property>
</bean>

<bean id="dao" class="za.co.xxxx.traintrack.server.DAO">
    <property name="sessionFactory" ref="sessionFactory"/>
    <property name="adminUsername" value="${admin.user.name}"/>
    <property name="adminPassword" value="${admin.user.password}"/>
    <property name="godUsername" value="${god.user.name}"/>
    <property name="godPassword" value="${god.user.password}"/>
</bean>

第二天一切顺利无效：

INFO   | jvm 1    | 2010/06/15 14:42:27 | 2010-06-15 18:42:27,804 WARN 
[JDBCExceptionReporter] : SQL Error: 0, SQLState: 08S01
INFO   | jvm 1    | 2010/06/15 14:42:27 | 2010-06-15 18:42:27,821 ERROR 
[JDBCExceptionReporter] : The last packet successfully received from the server 
was 38729 seconds ago.The last packet sent successfully to the server was 38729
seconds ago, which  is longer than the server configured value of 'wait_timeout'.
You should consider either expiring and/or testing connection validity before 
use in your application, increasing the server configured values for client
timeouts, or using the Connector/J connection property 'autoReconnect=true' to
avoid this problem.
INFO   | jvm 1    | 2010/06/15 14:42:27 | Jun 15, 2010 6:42:27 PM 
org.apache.catalina.core.ApplicationContext log
INFO   | jvm 1    | 2010/06/15 14:42:27 | SEVERE: Exception while dispatching
incoming RPC call

我已经阅读了很多不同的东西（没有一个有效），请帮忙

Answer 1

请查看此链接http://www.databasesandlife.com/automatic-reconnect-from-hibernate-to-mysql/

 In “hibernate.cfg.xml”:

<!-- hibernate.cfg.xml -->
<property name="c3p0.min_size">5</property>
<property name="c3p0.max_size">20</property>
<property name="c3p0.timeout">1800</property>
<property name="c3p0.max_statements">50</property>
<property name="connection.provider_class">
   org.hibernate.connection.C3P0ConnectionProvider</property>
<!-- no "connection.pool_size" entry! -->

然后创建一个文件“c3p0.properties”，它必须位于类路径的根目录中（即无法为应用程序的特定部分覆盖它）：

# c3p0.properties
c3p0.testConnectionOnCheckout=true

Answer 2

Romain，我没有hibernate.cfg.xml（全部在applicationContext.XML中完成）

c3p0.properties

c3p0.testConnectionOnCheckout=true

的applicationContext.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:tx="http://www.springframework.org/schema/tx"
       xsi:schemaLocation="
           http://www.springframework.org/schema/context
           http://www.springframework.org/schema/context/spring-context-2.5.xsd
           http://www.springframework.org/schema/beans
           http://www.springframework.org/schema/beans/spring-beans-2.0.xsd
           http://www.springframework.org/schema/tx
           http://www.springframework.org/schema/tx/spring-tx-2.0.xsd
           ">

    <context:annotation-config/>

    <context:component-scan base-package="za.co.cmsoftware.traintrack.server"/>

    <!-- Application properties -->
    <bean id="propertyConfigurer" class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
        <property name="locations">
            <list>
                <value>file:${user.dir}/@propertiesFile@</value>
            </list>
        </property>
    </bean>

    <bean id="sessionFactory"
          class="org.springframework.orm.hibernate3.annotation.AnnotationSessionFactoryBean">
        <property name="hibernateProperties">
            <props>
                <prop key="hibernate.dialect">${connection.dialect}</prop>
                <prop key="hibernate.connection.username">${connection.username}</prop>
                <prop key="hibernate.connection.password">${connection.password}</prop>
                <prop key="hibernate.connection.url">${connection.url}</prop>
                <prop key="hibernate.connection.driver_class">${connection.driver.class}</prop>
                <prop key="hibernate.show_sql">${show.sql}</prop>
                <prop key="hibernate.hbm2ddl.auto">update</prop>
                <prop key="hibernate.c3p0.min_size">5</prop>
                <prop key="hibernate.c3p0.max_size">20</prop>
                <prop key="hibernate.c3p0.timeout">1800</prop>
                <prop key="hibernate.c3p0.max_statements">50</prop>
                <prop key="hibernate.c3p0.idle_test_period">300</prop>
                <prop key="connection.provider_class">org.hibernate.connection.C3P0ConnectionProvider</prop>
            </props>
        </property>
        <property name="annotatedClasses">
            <list>
                <value>za.co.xxxx.traintrack.server.model.Answer</value>
                <value>za.co.xxxx.traintrack.server.model.Company</value>
                <value>za.co.xxxx.traintrack.server.model.CompanyRegion</value>
                <value>za.co.xxxx.traintrack.server.model.Merchant</value>
                <value>za.co.xxxx.traintrack.server.model.Module</value>
                <value>za.co.xxxx.traintrack.server.model.Question</value>
                <value>za.co.xxxx.traintrack.server.model.User</value>
                <value>za.co.xxxx.traintrack.server.model.CompletedModule</value>
            </list>
        </property>
    </bean>

    <bean id="dao" class="za.co.xxxx.traintrack.server.DAO">
        <property name="sessionFactory" ref="sessionFactory"/>
        <property name="adminUsername" value="${admin.user.name}"/>
        <property name="adminPassword" value="${admin.user.password}"/>
        <property name="godUsername" value="${god.user.name}"/>
        <property name="godPassword" value="${god.user.password}"/>
    </bean>

    <bean id="transactionManager"
          class="org.springframework.orm.hibernate3.HibernateTransactionManager">
        <property name="sessionFactory">
            <ref local="sessionFactory"/>
        </property>
    </bean>

    <!-- enable the configuration of transactional behavior based on annotations -->
    <tx:annotation-driven transaction-manager="transactionManager"/>

</beans>

数据库连接超时

2 个答案: