java - MySQL 数据库连接几分钟后断开

Question

我正在使用 Spring+Hibernate+JSF，但是如果我在页面上工作几分钟，我在尝试一些数据库查询时会遇到异常

 The last packet successfully received from the server was 2,615,049 milliseconds ago.  The last packet sent successfully to the server was 27 milliseconds ago.

Caused by: org.hibernate.TransactionException: JDBC begin transaction failed: 
    at org.hibernate.engine.transaction.internal.jdbc.JdbcTransaction.doBegin(JdbcTransaction.java:76)
    at org.hibernate.engine.transaction.spi.AbstractTransactionImpl.begin(AbstractTransactionImpl.java:160)
    at org.hibernate.internal.SessionImpl.beginTransaction(SessionImpl.java:1309)
    at org.springframework.orm.hibernate4.HibernateTransactionManager.doBegin(HibernateTransactionManager.java:474)
    ... 46 more
Caused by: com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure

此问题是由于我的项目中的任何配置或其数据库供应商问题造成的吗 在 web.xml 中我做了这个条目

<session-config>
   <session-timeout>
          30
   </session-timeout>
 </session-config>

连接池

<bean id="DataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource" destroy-method="close">
        <property name="driverClass" value="com.mysql.jdbc.Driver" />
        <property name="jdbcUrl" value="jdbc:mysql://IP:3306/ccc" />
                <property name="user" value=" hariom" />
                <property name="password" value="password" />
        <property name="maxPoolSize" value="2" />
        <property name="maxStatements" value="0" />
        <property name="minPoolSize" value="1" />
</bean>

Answer 1

您应该添加此属性；

<property name="validationQuery" value="SELECT 1" />

这将验证连接，如果 mysql 关闭连接，您的应用程序将不会尝试发送数据包。