spring+hibernate配置c3p0无法释放数据库连接

弄了3天，还是没有搞定。
配置：
winxp+tomcat5.0.28+hibernate3.1+spring1.2.6+struts1.0+mysql5.0.17,做了一个小blog。没有配置连接池时，运转良好。用c3p0配置后，每次都会出现3或者5个新连接。然后发现数据库连接不能释放。出现很多sleep连接。直到全部连接占满。
出现：错误表现：

javax.servlet.ServletException: Hibernate operation: Cannot open connection; uncategorized SQLException for SQL [???]; SQL state [null]; error code [0]; Connections could not be acquired from the underlying database!; nested exception is java.sql.SQLException: Connections could not be acquired from the underlying database

数据库的表现是：

类似的问题，但没有都没有很好的解决方法。

引用

06-21-2006 spring论坛一问题。
http://forum.springframework.org/showthread.php?t=26124
JavaEye
求助,Spring+Hibernate连接池无法释放问题,贴出详细代码
http://www.iteye.com/topic/32378

下面是applicationContext.xml的配置：

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE beans PUBLIC "-//SPRING//DTD BEAN//EN" "http://www.springframework.org/dtd/spring-beans.dtd">

<beans>

<!-- for properties files -->
 <bean id="propertyConfigurer"
  class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
  <property name="locations">
   <list>
    <value>classpath:c3p0.properties</value>
   </list>
  </property>
 </bean>

<!-- for dataSource -->
<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="properties">
   <props>
    <prop key="c3p0.minPoolSize">${hibernate.c3p0.minPoolSize}</prop>
    <prop key="hc3p0.maxPoolSize">${hibernate.c3p0.maxPoolSize}</prop>
    <prop key="hc3p0.timeout">${hibernate.c3p0.timeout}</prop>
    <prop key="c3p0.max_statement">${hibernate.c3p0.max_statement}</prop>
    <prop key="user">${jdbc.username}</prop>
    <prop key="password">${jdbc.password}</prop>
    <prop key="c3p0.testConnectionOnCheckout">true</prop>
   </props>
  </property>
 </bean>

	
	<bean id="sessionFactory"
		class="org.springframework.orm.hibernate3.LocalSessionFactoryBean">

		<property name="dataSource">
			<ref bean="dataSource" />
		</property>
		<property name="mappingResources">
            <list>
                <value>com/voff/hibernate/Blog.hbm.xml</value>
            </list>
        </property>
		<property name="hibernateProperties">
			<props>
				<prop key="hibernate.dialect">
					org.hibernate.dialect.MySQLDialect
				</prop>
				<prop key="hibernate.show_sql">
				true
				</prop>
				<prop key="hibernate.connection.provider_class">
                org.hibernate.connection.C3P0ConnectionProvider
               </prop>
			</props>
		</property>
	</bean>
	
	 <!-- transactionManager -->
	 <bean id="transactionManager" class="org.springframework.orm.hibernate3.HibernateTransactionManager">
        <property name="sessionFactory">
            <ref bean="sessionFactory"/>
        </property>
    </bean>
    
    <bean id="BlogDao" class="com.voff.dao.BlogDaoimpl">
        <property name="sessionFactory">
            <ref bean="sessionFactory"/>
        </property>
    </bean>
    
    	<!-- spring dao proxy -->
    <bean id="BlogDaoProxy" class="org.springframework.transaction.interceptor.TransactionProxyFactoryBean">
        <property name="transactionManager">
            <ref bean="transactionManager"/>
        </property>
        <property name="proxyInterfaces">
            <list>
                <value>com.voff.dao.BlogDao</value>
            </list>
        </property>
        <property name="target">
            <ref bean="BlogDao"/>
        </property>
        <property name="transactionAttributes">
            <props>
                <prop key="insert">PROPAGATION_REQUIRED</prop>
                <prop key="save*">PROPAGATION_REQUIRED</prop>
                <prop key="update*">PROPAGATION_REQUIRED</prop>
                <prop key="find*">PROPAGATION_REQUIRED</prop>
                <prop key="*">PROPAGATION_REQUIRED,readOnly</prop>   
            </props>
        </property>
    
    </bean>
    
	</beans>

c3p0.properties的配置是：

jdbc.driver=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql://localhost/spring?useUnicode=true&characterEncoding=UTF-8
jdbc.username=root
jdbc.password=

hibernate.c3p0.minPoolSize=5
hibernate.c3p0.maxPoolSize=20
hibernate.c3p0.timeout=100
hibernate.c3p0.max_statement=50

BlogDaoimpl的代码是：

package com.voff.dao;

import java.util.ArrayList;
import java.util.List;

import org.hibernate.Query;
import org.hibernate.Session;
import org.springframework.orm.hibernate3.support.HibernateDaoSupport;

import com.voff.hibernate.Blog;



public class BlogDaoimpl extends HibernateDaoSupport implements BlogDao{

	public void addblog(Blog blog) {
		getHibernateTemplate().save(blog);
		
		
	}

	public void delblog(int id) {

		Object blog=getHibernateTemplate().load(Blog.class,id);    
		 getHibernateTemplate().delete(blog); 

		
	}

	public void updateblog(Blog blog) {
		getHibernateTemplate().update(blog);

		
	}
	
	public Blog getblog(int id){
		return (Blog) getHibernateTemplate().get(Blog.class,id);
	}
	
	
   public int Totallimitblog(int caid,String bauthor){
	   String sql = "from Blog where cateid='"+caid+"' and bauthor ='"+bauthor+"'";
		  List total = getHibernateTemplate().find(sql);

		return total.size();
   }
	
	public ArrayList showblog(int firstRow,int maxRow,int caid,String bauthor){
		List   list=new   ArrayList();   

		  Session   session  =  getHibernateTemplate().getSessionFactory().openSession();   
		  Query   query   =session.createQuery("from Blog where cateid='"+caid+"' and bauthor ='"+bauthor+"' order by blogid desc");   
		  query.setFirstResult(firstRow);   
		  query.setMaxResults(maxRow);   
		  list=query.list();  
		  session.flush();
		  session.close();
		  return   (ArrayList) list;
	}




}

请各位高手帮我看看，到底是什么原因（连接池问题，还是代码问题（不用连接池运转良好）导致数据库sleep连接不能释放。谢谢！

评论

2 楼 voff12 2007-06-06  

tonyyl 写道

数据源配的有问题，应该用spring的数据源，由于hibernate本身支持c3p0，你只要在sessionFactory的hibernateProperties里配c3p0的属性即可。

楼主是新手吧？此帖应该发在新手区

谢谢回复。为何直接c3p0的数据源不行？按你的方法配置，MySQL Administator检测不出数据库连接。连接数量只有一个！

<bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource" >
     <property name="driverClassName">
			<value>com.mysql.jdbc.Driver</value>
		</property>
		<property name="url">
			<value>jdbc:mysql://localhost/spring?useUnicode=true&characterEncoding=UTF-8</value>
		</property>
		<property name="username">
			<value>root</value>
		</property>
	</bean>


	
	<bean id="sessionFactory"
		class="org.springframework.orm.hibernate3.LocalSessionFactoryBean">

		<property name="dataSource">
			<ref bean="dataSource" />
		</property>
		<property name="mappingResources">
            <list>
                <value>com/voff/hibernate/Blog.hbm.xml</value>
            </list>
        </property>
		<property name="hibernateProperties">
			<props>
				<prop key="hibernate.dialect">
					org.hibernate.dialect.MySQLDialect
				</prop>
				<prop key="hibernate.show_sql">
				true
				</prop>
				<prop key="hibernate.connection.provider_class">
                org.hibernate.connection.C3P0ConnectionProvider
               </prop>
               <prop  key="hibernate.c3p0.max_size">20</prop>
               <prop key="hibernate.c3p0.min_size">5</prop>
               <prop  key="hibernate.c3p0.timeout">15000</prop>
               <prop key="hibernate.c3p0.max_statements">100</prop>
               <prop  key="hibernate.c3p0.idle_test_period">120</prop>
               <prop  key="hibernate.c3p0.acquire_increment">2</prop>
			</props>
		</property>
	</bean>

1 楼 tonyyl 2007-06-06  

数据源配的有问题，应该用spring的数据源，由于hibernate本身支持c3p0，你只要在sessionFactory的hibernateProperties里配c3p0的属性即可。

楼主是新手吧？此帖应该发在新手区