项目结构是：springmvc +hibernate+mysql，
数据库连接池：C3P0
服务器使用的是tomcat7
出现的状况是：访问的时候经常出现404错误
实验的过程刚开始以为是数据库版本的问题，但是用过了各个版本，包括操作系统用windows,linux都试过，错误是一样的。
也试过网络上面讲的改变mysql的配置文件，增加连接时间，但是错误依旧。
在和我们公司的汪总和程序员沟通之后，终于得到解决。
原因是
HIBERNATE的配置不一定能管理动C3P0
出现的错误提示：
HTTP Status 500 - Request processing failed; nested exception is org.springframework.orm.hibernate3.HibernateSystemException: JDBC commit failed; nested exception is org.hibernate.TransactionException: JDBC commit failed type Exception report message Request processing failed; nested exception is org.springframework.orm.hibernate3.HibernateSystemException: JDBC commit failed; nested exception is org.hibernate.TransactionException: JDBC commit failed description The server encountered an internal error that prevented it from fulfilling this request. exception org.springframework.web.util.NestedServletException: Request processing failed; nested exception is org.springframework.orm.hibernate3.HibernateSystemException: JDBC commit failed; nested exception is org.hibernate.TransactionException: JDBC commit failed org.springframework.orm.hibernate3.HibernateSystemException: JDBC commit failed; nested exception is org.hibernate.TransactionException: JDBC commit failed com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException: No operations allowed after connection closed. com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure The last packet successfully received from the server was 149,464 milliseconds ago. The last packet sent successfully to the server was 18,923 milliseconds ago. java.net.SocketTimeoutException: Read timed out |
解决问题的办法是改变spring的配置文件applicationContext.xml，增加相关的配置
在<beans>标签内加入下面相关的配置：
<bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource" destroy-method="close"> <property name="driverClass" value="${jdbc.driver}" /> <property name="jdbcUrl" value="${jdbc.url}" /> <property name="user" value="${jdbc.username}" /> <property name="password" value="${jdbc.password}" /> <property name="initialPoolSize" value="${connection_pools.initial_pool_size}" /> <property name="minPoolSize" value="${connection_pools.min_pool_size}" /> <property name="maxPoolSize" value="${connection_pools.max_pool_size}" /> <property name="maxIdleTime" value="${connection_pools.max_idle_time}" /> <property name="acquireIncrement" value="${connection_pools.acquire_increment}" /> <property name="checkoutTimeout" value="${connection_pools.checkout_timeout}" /> <property name="testConnectionOnCheckin" value="false"/> <property name="testConnectionOnCheckout" value="true"/> <property name="preferredTestQuery" value="SELECT 1"/> </bean> |
配置完重启服务器就可以了