2

我有一个使用 Hibernate 4.1.1 和 Spring 3.1.1 和 Postgres 9.2 的 Java/Wicket 网络应用程序。我还使用 spring transaction api 和 c3p0 连接池。

我的问题是未释放可用连接，并且在执行由 gui 引​​起的一些选择语句后，我得到以下异常

com.mchange.v2.resourcepool.CannotAcquireResourceException：ResourcePool 无法从其主要工厂或来源获取资源。执行SELECT * FROM pg_stat_activity;显示有很多这样的空闲查询：SELECT NULL AS TABLE_CAT, n.nspname AS TABLE_SCHEM, c.relname AS TABLE_NAME, CASE n.nspname ~ '^pg_' OR n.nspname = 'information_schema' WHEN true THEN CASE WHEN n.nspname = 'pg_catalog' OR n.nspname = 'information_schema' THEN CASE c.relkind WHEN 'r' THEN 'SYSTEM TABLE' WHEN 'v' THEN 'SYSTEM VIEW' WHEN 'i' THEN 'SYSTEM INDEX' ELSE NULL END WHEN n.nspname = 'pg_toast' THEN CASE c.relkind WHEN 'r' THEN 'SYSTEM TOAST TABLE' WHEN 'i' THEN 'SYSTEM TOAST INDEX' ELSE NULL END ELSE CASE c.relkind
WHEN 'r' THEN 'TEMPORARY TABLE' WHEN 'i' THEN 'TEMPORARY INDEX'
WHEN 'S' THEN 'TEMPORARY SEQUENCE' WHEN 'v' THEN 'TEMPORARY VIEW'
ELSE NULL END END WHEN false THEN CASE c.relkind WHEN 'r' THEN 'TABLE' WHEN 'i' THEN 'INDEX' WHEN 'S' THEN 'SEQUENCE' WHEN 'v' THEN 'VIEW' WHEN 'c' THEN 'TYPE' ELSE NULL END ELSE NULL END AS TABLE_TYPE, d.description AS REMARKS FROM pg_catalog.pg_namespace n, pg_catalog.pg_class c LEFT JOIN pg_catalog.pg_description d ON (c.oid = d.objoid AND d.ob

这是我的 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:util="http://www.springframework.org/schema/util"
       xmlns:tx="http://www.springframework.org/schema/tx"
       xmlns:aop="http://www.springframework.org/schema/aop"
       xmlns:lang="http://www.springframework.org/schema/lang"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.1.xsd
                           http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util-3.1.xsd
                           http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.1.xsd
                           http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.1.xsd
                           http://www.springframework.org/schema/lang http://www.springframework.org/schema/lang/spring-lang-3.1.xsd"
       default-autowire="byName">


    <bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource"
                    destroy-method="close">
           <property name="driverClass" value="org.postgresql.Driver"/>
           <property name="jdbcUrl" value="jdbc:postgresql://localhost:5432/mydatabase"/>
           <property name="user" value="myuser"/>
           <property name="password" value="mypassword"/>

           <!-- configuration pool via c3p0 -->
           <property name="initialPoolSize" value="3"/>
           <property name="minPoolSize" value="3"/>
           <property name="maxPoolSize" value="30"/>
           <property name="idleConnectionTestPeriod" value="600"/>
           <property name="maxIdleTime" value="0"/>
           <property name="maxStatements" value="0"/>
           <property name="maxStatementsPerConnection" value="0"/>
           <property name="acquireIncrement" value="1"/>
           <property name="acquireRetryAttempts" value="3"/>
           <property name="acquireRetryDelay" value="1000"/>
           <property name="autoCommitOnClose" value="false"/>
           <property name="maxConnectionAge" value="14400"/>
           <property name="forceIgnoreUnresolvedTransactions" value="false"/>
           <property name="numHelperThreads" value="20"/>
           <property name="testConnectionOnCheckin" value="false"/>
           <property name="testConnectionOnCheckout" value="false"/>
           <property name="maxAdministrativeTaskTime" value="0"/>
           <property name="debugUnreturnedConnectionStackTraces" value="false"/>
           <property name="maxIdleTimeExcessConnections" value="0"/>
           <property name="breakAfterAcquireFailure" value="false"/>
           <property name="checkoutTimeout" value="0"/>
           <property name="unreturnedConnectionTimeout" value="0"/>
           <property name="usesTraditionalReflectiveProxies" value="false"/>
      </bean>

    <bean id="exampleDao"
        class="com.mycompany.persistence.hibernate.daoimpl.ExampleDaoImpl">
        <property name="sessionFactory" ref="sessionFactory" />
    </bean>


    <bean id="sessionFactory"
        class="org.springframework.orm.hibernate4.LocalSessionFactoryBean">
      <property name="dataSource" ref="dataSource" />
      <property name="annotatedClasses">
        <list>
            <value>com.mycompany.model.Example</value>
        </list>
      </property>

      <property name="hibernateProperties">
        <props>
            <prop key="hibernate.dialect">org.hibernate.dialect.PostgreSQLDialect</prop>
            <prop key="hibernate.show_sql">true</prop>
            <prop key="hibernate.format_sql">true</prop>
            <prop key="hibernate.current_session_context_class">org.springframework.orm.hibernate4.SpringSessionContext</prop>
            <prop key="hibernate.auto_close_session">true</prop>
            <prop key="hibernate.c3p0.maxSize">30</prop>
            <prop key="hibernate.c3p0.minSize">1</prop>
            <prop key="hibernate.c3p0.acquireIncrement">1</prop>
            <prop key="hibernate.c3p0.idleTestPeriod">300</prop>
            <prop key="hibernate.c3p0.timeout">1800</prop>
            <prop key="hibernate.c3p0.maxStatements">0</prop>
            <prop key="hibernate.c3p0.unreturnedConnectionTimeout">30</prop> 
            <prop key="hibernate.c3p0.debugUnreturnedConnectionStackTraces">true</prop>
            <prop key="hibernate.c3p0.checkoutTimeout">0</prop>
            <prop key="hibernate.c3p0.preferredTestQuery">SELECT * FROM dual</prop>
        </props>
      </property>
    </bean>

   <!-- Transaction Management -->
   <tx:annotation-driven transaction-manager="transactionManager"/>
    <bean id="transactionManager"
    class="org.springframework.orm.hibernate4.HibernateTransactionManager">
        <property name="sessionFactory" ref="sessionFactory"/>
    </bean>
</beans>

配置是否正确？

我从数据库中检索数据的类是这样的：

@Repository
public class ExampleDaoImpl extends BaseDaoImpl implements ExampleDao {
...
    @Override
    @Transactional(readOnly=true)
    public List<Example> findExampleByCompanyAndType(Company company,
            int type) {
        return sessionFactory.getCurrentSession()
                .createCriteria(Example.class)
                .add(Restrictions.eq("company.companyId",
                        company.getCompanyId()))
                .add(Restrictions.eq("type", type)).list();

    }
...
}
4

1 回答 1

1

PostgreSQL 没有实现“双重”，因此您可能打算在那里使用 SELECT 1 之类的东西来进行测试查询。我不知道这是否会解决您的问题，但它应该有助于容器更好地自我管理。

于 2013-04-12T13:16:48.110 回答