使用spring配置c3p0出问题，mysql和c3p0的jar包都导入了，没有语法错误，但是出问题了，配置文件为：
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异常：警告: Exception encountered during context initialization - cancelling refresh attempt: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'dataSource' defined in class path resource [bean-dataSource.xml]: Instantiation of bean failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [com.mchange.v2.c3p0.ComboPooledDataSource]: No default constructor found; nested exception is java.lang.NoClassDefFoundError: com/mchange/v2/ser/Indirector
