就我所知,SSH框架配置的开源数据库连接池有4种,分别是DBCP、C3P0、Proxool、BoneCP。工作中最先接触使用的是DBCP,之后又使用了C3P0。最近在使用hibernate分页功能时,发现重复频繁的使用分页查询时数据库连接会得不到释放!!!我的分页查询使用的语句是:
Query query = getSession().createQuery(hql);
Pager pager = pageHelper.getPager(getRows(pageHelper.getHql()));
query.setFirstResult(pager.getStartRow());
query.setMaxResults(pager.getPageSize());
return query.list();
在网上查了查,一种方案说是使用getSession()造成的,建议利用HibernateTemplate替换,想想改动太大而且本人习惯传hql,只好舍弃(是否有效还需要验证)。
另外有方案说是在配置C3P0方面有问题,我检查了多遍,也尝试诸多修改方案,未见效果,实在不知道问题出在哪里!如果哪位大虾看到还请帮忙!我的C3P0配置如下:
<bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource" destroy-method="close">
<property name="maxPoolSize" value="${c3p0.maxPoolSize}" />
<property name="minPoolSize" value="${c3p0.minPoolSize}" />
<property name="maxIdleTime" value="${c3p0.maxIdleTime}" />
<property name="maxStatements" value="${c3p0.maxStatements}" />
<property name="acquireIncrement" value="${c3p0.acquireIncrement}" />
<property name="idleConnectionTestPeriod" value="${c3p0.idleConnectionTestPeriod}" />
<property name="acquireRetryAttempts" value="${c3p0.acquireRetryAttempts}" />
<property name="breakAfterAcquireFailure" value="${c3p0.breakAfterAcquireFailure}" />
<property name="testConnectionOnCheckout" value="${c3p0.testConnectionOnCheckout}" />
<property name="driverClass" value="${jdbc.driverClassName}" />
<property name="jdbcUrl" value="${jdbc.url}" />
<property name="user" value="${jdbc.username}" />
<property name="password" value="${jdbc.password}" />
</bean>
<bean id="sessionFactory" class="org.springframework.orm.hibernate3.LocalSessionFactoryBean">
<property name="dataSource">
<ref local="dataSource" />
</property>
<property name="mappingResources">
<list>
<value>model/TSysUser.hbm.xml</value>
</list>
</property>
<property name="hibernateProperties">
<props>
<prop key="hibernate.dialect">${hibernate.dialect}</prop>
<prop key="hibernate.show_sql">${hibernate.show_sql}</prop>
<prop key="hibernate.format_sql">${hibernate.format_sql}</prop>
<prop key="hibernate.jdbc.batch_size">${hibernate.jdbc.batch_size}</prop>
<prop key="hibernate.connection.release_mode">auto</prop>
<prop key="hibernate.autoReconnect">true</prop>
<prop key="hibernate.connection.provider_class">org.hibernate.connection.C3P0ConnectionProvider</prop>
</props>
</property>
</bean>
<bean id="transactionManager" class="org.springframework.orm.hibernate3.HibernateTransactionManager">
<property name="sessionFactory" ref="sessionFactory"/>
</bean>
<!-- service manager Template-->
<bean id="transactionProxyTemplate"
class="org.springframework.transaction.interceptor.TransactionProxyFactoryBean" lazy-init="true"
abstract="true">
<property name="transactionManager" ref="transactionManager"/>
<property name="transactionAttributes">
<props>
<prop key="save*">PROPAGATION_REQUIRED</prop>
<prop key="delete*">PROPAGATION_REQUIRED</prop>
<prop key="remove*">PROPAGATION_REQUIRED</prop>
<prop key="update*">PROPAGATION_REQUIRED</prop>
<prop key="*">PROPAGATION_REQUIRED,readOnly</prop>
</props>
</property>
</bean>
<!-- service manager -->
<bean id="userService" parent="transactionProxyTemplate">
<property name="target">
<bean class="user.service.impl.UserServiceImpl">
<property name="dao" ref="dao"/>
</bean>
</property>
<property name="proxyInterfaces">
<value>user.service.IUserService</value>
</property>
</bean>
<bean id="daoTemplate" class="dao.BaseDAO" abstract="true" lazy-init="true">
<property name="sessionFactory" ref="sessionFactory"/>
</bean>
<bean id="dao" class="dao.Dao" parent="daoTemplate"/>
不得以根据修改连接池配置这个思路,想想干脆换一个连接池试试,于是找上了Proxool。经过重新配置并作了测试,发现问题解决,不再发现有数据库连接不释放的情况!有机会再试试BoneCP,听说这个性能是最优的!?
在此推荐一篇博客,虽然也是转载的,但里面对这几种连接池介绍的都比较详细,另外还作了测试对比,厉害。
http://ahcaizhiming.blog.163.com/blog/static/136765452201342185929695/