DEBUG -- CLOSE BY CLIENT STACK TRACE问题的两种解决方案，整理自网络

1.DEBUG -- CLOSE BY CLIENT STACK TRACE
最近用c3p0遇到各种奇怪的问题，也不知道是它不行还是我不行。
今天又遇到了一个“DEBUG -- CLOSE BY CLIENT STACK TRACE”这个错误。
在网上找了找，大家都是抄的一篇文章，也不知道问题解决没解决，反正很多人都抄了这篇文章：
http://hi.baidu.com/xhr8334/blog/item/cf15d1a6deb235fc9052ee9b.html

将日志级别提升，就算解决问题了吗？最多只能算是眼不见心不烦。

研究后我发现了一个不报这个错的方法：
<bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource" destroy-method="close">
        <property name="driverClass" value="${jdbc.driverClassName}"/>
        <property name="jdbcUrl" value="${jdbc.url}" />
        <property name="user" value="${jdbc.username}" />
        <property name="password" value="${jdbc.password}" />
        <property name="minPoolSize" value="${c3p0.minPoolSize}"/>
        <property name="maxPoolSize" value="${c3p0.maxPoolSize}"/>
        <property name="initialPoolSize" value="${c3p0.initialPoolSize}"/>
        <property name="maxIdleTime" value="${c3p0.maxIdleTime}"/>
        <property name="maxStatements" value="${c3p0.max_statement}"/>
    </bean>

将配置文件中的红字去掉就好了。
原理请看：http://blog.csdn.net/hallelujah_chen/article/details/6016132

2.ORACLE CLOSE BY CLIENT STACK TRACE

部署一个项目启动的时候debug打印出好多错误

其中，CLOSE BY CLIENT STACK TRACE 是第一错误
使用的是Myeclipse 8.5
框架： hibernate 3.0 ，spring 3.0 ，maven2 等
web服务器：resin3.1.10

错误信息如下所示：
Exception代码
java.lang.Exception: DEBUG -- CLOSE BY CLIENT STACK TRACE
    at com.mchange.v2.c3p0.impl.NewPooledConnection.close(NewPooledConnection.java:566)
    at com.mchange.v2.c3p0.impl.NewPooledConnection.close(NewPooledConnection.java:234)
    at com.mchange.v2.c3p0.impl.C3P0PooledConnectionPool$1PooledConnectionResourcePoolManager.destroyResource(C3P0PooledConnectionPool.java:470)
    at com.mchange.v2.resourcepool.BasicResourcePool$1DestroyResourceTask.run(BasicResourcePool.java:964)
    at com.mchange.v2.resourcepool.BasicResourcePool.destroyResource(BasicResourcePool.java:989)
    at com.mchange.v2.resourcepool.BasicResourcePool.access$100(BasicResourcePool.java:32)
    at com.mchange.v2.resourcepool.BasicResourcePool$5.run(BasicResourcePool.java:1174)
…………
Caused by: org.springframework.aop.framework.AopConfigException: Cannot proxy target class because CGLIB2 is not available.
Add CGLIB to the class path or specify proxy interfaces.

java.lang.Exception: DEBUG -- CLOSE BY CLIENT STACK TRACE
at com.mchange.v2.c3p0.impl.NewPooledConnection.close(NewPooledConnection.java:566)
at com.mchange.v2.c3p0.impl.NewPooledConnection.close(NewPooledConnection.java:234)
at com.mchange.v2.c3p0.impl.C3P0PooledConnectionPool$1PooledConnectionResourcePoolManager.destroyResource(C3P0PooledConnectionPool.java:470)
at com.mchange.v2.resourcepool.BasicResourcePool$1DestroyResourceTask.run(BasicResourcePool.java:964)
at com.mchange.v2.resourcepool.BasicResourcePool.destroyResource(BasicResourcePool.java:989)
at com.mchange.v2.resourcepool.BasicResourcePool.access$100(BasicResourcePool.java:32)
at com.mchange.v2.resourcepool.BasicResourcePool$5.run(BasicResourcePool.java:1174)
…………

Caused by: org.springframework.aop.framework.AopConfigException: Cannot proxy target class because CGLIB2 is not available.
Add CGLIB to the class path or specify proxy interfaces.

解决方法：

在maven2的配置文件中，初始化下载的一些jar包中，加入cglib2.2 jar包的下载

Xml代码
<dependency>
    <groupId>cglib</groupId>
    <artifactId>cglib</artifactId>
    <version>2.2</version>
</dependency>

<dependency>
<groupId>cglib</groupId>
<artifactId>cglib</artifactId>
<version>2.2</version>
</dependency>

再次启动时，debug报错消失

在resin服务器的lib下发现，当配置上面的xml时候，会有包 cglib-2.2.jar 加载过来

可见，以上的错误信息是由于缺少这个包造成的，在相应的 lib中加入该包，就不会有这个问题了。