我一直在努力解决这个问题.我有一个使用Struts2,spring和Hibernate的基于Web的应用程序.我使用Spring将struts动作和业务以及dao层连接在一起.
    我正在使用JMeter加载测试应用程序.当我模拟1个用户反复发送get请求时,该应用程序运行良好,没有问题.但是当我添加几个用户时,一段时间后我收到以下错误：

Caused by: org.hibernate.exception.GenericJDBCException: Cannot open connection
    at org.hibernate.exception.SQLStateConverter.handledNonSpecificException(SQLStateConverter.java:140)
    at org.hibernate.exception.SQLStateConverter.convert(SQLStateConverter.java:128)
    at org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:66)
    at org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:52)
    at org.hibernate.jdbc.ConnectionManager.openConnection(ConnectionManager.java:449)
    at org.hibernate.jdbc.ConnectionManager.getConnection(ConnectionManager.java:167)
    at org.hibernate.jdbc.JDBCContext.connection(JDBCContext.java:160)
    at org.hibernate.transaction.JDBCTransaction.begin(JDBCTransaction.java:81)
    at org.hibernate.impl.SessionImpl.beginTransaction(SessionImpl.java:1473)
    at org.springframework.orm.hibernate3.HibernateTransactionManager.doBegin(HibernateTransactionManager.java:510)
    ... 104 more
Caused by: java.sql.SQLException: Listener refused the connection with the following error:
ORA-12519, TNS:no appropriate service handler found
The Connection descriptor used by the client was:
192.168.1.118:1521:BAADB

    at oracle.jdbc.driver.DatabaseError.throwSqlException(DatabaseError.java:112)
    at oracle.jdbc.driver.DatabaseError.throwSqlException(DatabaseError.java:261)
    at oracle.jdbc.driver.T4CConnection.logon(T4CConnection.java:387)
    at oracle.jdbc.driver.PhysicalConnection.<init>(PhysicalConnection.java:414)
    at oracle.jdbc.driver.T4CConnection.<init>(T4CConnection.java:165)
    at oracle.jdbc.driver.T4CDriverExtension.getConnection(T4CDriverExtension.java:35)
    at oracle.jdbc.driver.OracleDriver.connect(OracleDriver.java:801)
    at java.sql.DriverManager.getConnection(DriverManager.java:582)
    at java.sql.DriverManager.getConnection(DriverManager.java:154)
    at org.springframework.jdbc.datasource.DriverManagerDataSource.getConnectionFromDriverManager(DriverManagerDataSource.java:173)
    at org.springframework.jdbc.datasource.DriverManagerDataSource.getConnectionFromDriver(DriverManagerDataSource.java:164)
    at org.springframework.jdbc.datasource.AbstractDriverBasedDataSource.getConnectionFromDriver(AbstractDriverBasedDataSource.java:149)
    at org.springframework.jdbc.datasource.AbstractDriverBasedDataSource.getConnection(AbstractDriverBasedDataSource.java:119)
    at org.springframework.orm.hibernate3.LocalDataSourceConnectionProvider.getConnection(LocalDataSourceConnectionProvider.java:81)
    at org.hibernate.jdbc.ConnectionManager.openConnection(ConnectionManager.java:446)
    ... 109 more 

所以,我假设它的连接泄漏,但是当我模拟单个用户不断发送请求时,我不应该得到相同的错误(唯一的区别是,我稍后会得到错误).在执行任何dao请求之前,我启用了Hibernate stats来检查打开会话的数量.处理完请求后,所有会话都将关闭.我正在使用OpenSessionInViewFilter,因此每个请求都有一个会话.

以下是所有文件
web.xml中：

<?xml version="1.0" encoding="ISO-8859-1"?>
<!DOCTYPE web-app
    PUBLIC "-//Sun Microsystems, Inc.//DTD Web Application 2.2//EN"
    "http://java.sun.com/j2ee/dtds/web-app_2_2.dtd">
<web-app>
    <context-param>
        <param-name>contextConfigLocation</param-name>
        <param-value>
            /WEB-INF/applicationContext-security.xml
            /WEB-INF/spring-database.xml
            /WEB-INF/application-action.xml
            /WEB-INF/newbeans.xml
        </param-value>
    </context-param>
    <filter> <!-- Get spring to keep the session open for the whole request, so Hibernates lazy loads work -->
        <filter-name>openSessionInViewFilter</filter-name>
        <filter-class>org.springframework.orm.hibernate3.support.OpenSessionInViewFilter</filter-class>
    </filter>
    <filter-mapping>
        <filter-name>openSessionInViewFilter</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>

    <filter>
        <filter-name>springSecurityFilterChain</filter-name>
        <filter-class>org.springframework.web.filter.DelegatingFilterProxy</filter-class>
    </filter>
    <filter-mapping>
        <filter-name>springSecurityFilterChain</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>

    <!-- - Loads the root application context of this web app at startup. - 
        The application context is then available via - WebApplicationContextUtils.getWebApplicationContext(servletContext). -->
    <listener>
        <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
    </listener>

    <listener>
        <listener-class>
            net.sf.navigator.menu.MenuContextListener</listener-class>
    </listener>

    <context-param>
        <param-name>log4jConfigLocation</param-name>
        <param-value>/WEB-INF/classes/log4j.properties</param-value>
    </context-param>

    <listener>
        <listener-class>org.springframework.web.util.Log4jConfigListener</listener-class>
    </listener>
    <filter>
        <filter-name>struts2</filter-name>
        <filter-class>org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter</filter-class>
    </filter>
    <filter-mapping>
        <filter-name>struts2</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>
</web-app>

Spring和Hibernate文件

<beans xmlns="http://www.springframework.org/schema/beans"
               xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
               xmlns:aop="http://www.springframework.org/schema/aop"
               xmlns:tx="http://www.springframework.org/schema/tx"
               xsi:schemaLocation="
               http://www.springframework.org/schema/beans 
               http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
               http://www.springframework.org/schema/tx 
               http://www.springframework.org/schema/tx/spring-tx-3.0.xsd
               http://www.springframework.org/schema/aop 
               http://www.springframework.org/schema/aop/spring-aop-3.0.xsd">
    <tx:annotation-driven/>
    <bean id="myDataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
        <property name="driverClassName" value="oracle.jdbc.driver.OracleDriver" />
        <property name="url" value="jdbc:oracle:thin:@192.168.1.118:1521:BAADB" />
        <property name="username" value="htwork" />
        <property name="password" value="*****" />
    </bean>         
    <bean id="sessionFactory" class="org.springframework.orm.hibernate3.annotation.AnnotationSessionFactoryBean">
        <property name="dataSource" ref="myDataSource" />
        <property name="annotatedClasses">
            <list>
                <value>com.tda.ht.bean.SerialNumbers</value>
                <value>com.tda.ht.bean.Bunos</value>
                <value>com.tda.ht.bean.Tms</value>
                <value>com.tda.ht.bean.Custodian</value>
                <value>com.tda.ht.bean.CMISConfEntry</value>
                <value>com.tda.ht.bean.HeloTrackCurrentBunoConf</value>
                <value>com.tda.ht.bean.RepairBean</value>
                <value>com.tda.ht.bean.TDIncorporation</value>
                <value>com.tda.ht.bean.Miscellaneous</value>
                <value>com.tda.ht.bean.Inspection</value>
                <value>com.tda.ht.bean.HTComponentHistory</value>
                <value>com.tda.ht.bean.Component</value>
                <value>com.tda.baa.dao.TransferRequest</value>
                <value>com.tda.baa.dao.UsersTable</value>
                <value>com.tda.baa.dao.UserRoles</value>
                <value>com.tda.ht.bean.EHRCurrentBunoConf</value>
                <value>com.tda.ht.bean.SRCCurrentBunoConf</value>
                <value>com.tda.ht.bean.ASRCurrentBunoConf</value>
                <value>com.tda.ht.bean.ASRSubCurrentBunoConf</value>
                <value>com.tda.ht.bean.ASRTree</value>
                <value>com.tda.ht.bean.PMICTree</value>
            </list>
        </property>
        <property name="hibernateProperties">
            <props>
                <prop key="hibernate.dialect">org.hibernate.dialect.OracleDialect</prop>
                <prop key="hibernate.show_sql">true</prop>
                <prop key="hibernate.generate_statistics">true</prop>
                <prop key="hibernate.c3p0.min_size">5</prop>
                <prop key="hibernate.c3p0.max_size">20</prop>
                <prop key="hibernate.c3p0.timeout">300</prop>
                <prop key="hibernate.c3p0.max_statements">50</prop>
                <prop key="hibernate.c3p0.idle_test_period">3000</prop>
            </props>
        </property>
    </bean>
    <bean id="transactionManager" class="org.springframework.orm.hibernate3.HibernateTransactionManager">
        <property name="sessionFactory" ref="sessionFactory"/>
    </bean>

    <bean id="componentDAO" class="com.tda.ht.dao.component.ComponentDAOImpl">
        <property name="sessionFactory" ref="sessionFactory"></property>
    </bean>

    <bean id="componentBusiness" class="com.tda.ht.business.component.ComponentBusinessImpl">
        <property name="iCompDAO" ref="componentDAO"></property>
    </bean>
</beans>

请求componentBusiness的Action方法调用 – 由spring管理

public String displayHeader() {
    Component c = componentBusiness.getComponentByPartNumber(partNumber);
    return SUCCESS;
}

业务层

package com.tda.ht.business.component;
import java.util.List;
import org.springframework.transaction.annotation.Transactional;
import com.tda.ht.bean.Component;
import com.tda.ht.dao.component.IComponentDAO;

public class ComponentBusinessImpl implements IComponentBusiness {
    private IComponentDAO iCompDAO;

    //service layer method, transactions handled by spring
    @Transactional(readOnly = true)
    public Component getComponentByPartNumber(String partNumber) {
        // TODO Auto-generated method stub
        return iCompDAO.getComponentByPartNumber(partNumber);
    }
}

DAO层

public class ComponentDAOImpl implements IComponentDAO {

SessionFactory sessionFactory;

protected static org.apache.log4j.Logger log = Logger
                .getLogger(ComponentDAOImpl.class);

//dao method called from service layer

@Override
public Component getComponentByPartNumber(String partNumber) {
    String[] arguments = { partNumber };

    long open = sessionFactory.getStatistics().getSessionOpenCount();
    long close = sessionFactory.getStatistics().getSessionCloseCount();

        log.error("Open " + open + " Close " + close);
        Session s = sessionFactory.getCurrentSession();

        log.error(" SESSION IS " + s.hashCode());

        try {
            Query q = s.createQuery("Select entry from Component as entry where entry.partNumber = ?");

            q.setParameter(0, partNumber);
            List<Component> list = q.list();

            if (list.size() > 0)
                return list.get(0);

            return null;
        }catch (Exception e) {
            e.printStackTrace();
        }finally {
            //s.close();
        }
    return null;
    }        
}

在dao层,我收集有关打开和关闭会话的统计信息,因为我模拟了4个用户,所以差异从不超过4.看起来所有会话都被关闭了.处理请求时.如果我不使用spring并使用自己的SessionFactory自己管理Hibernate,打开和关闭会话,一切正常并且没有错误.
我很困惑,因为我没有看到任何Sessions被泄露,任何指针将不胜感激.

解决方法:

DriverManagerDataSource不打算用于生产,在生产中你想要使用连接池,DriverManagerDataSource不是连接池,我建议使用像Tomcat JDBC或Commons DBCP这样的连接池.

您的hibernate.c3p0设置是无用的,因为您正在使用Spring配置和注入数据源,因此将忽略这些属性.

最后你DAO代码(可能)有缺陷,你不应该抓住并吞下Exception,因为这可能会破坏正确的tx管理.

如果希望Log4j正确初始化,则应在ContextLoaderListener之前配置Log4jConfigListener的最终,无关的提示.虽然我怀疑你需要它,因为log4j.xml在yuor类路径上,所以可能Log4J已经初始化了.