Hibernate4.3.8.Final在配置c3p0时，报错

Initial SessionFactory creation failed.org.hibernate.service.spi.ServiceException: Unable to create requested service [org.hibernate.engine.jdbc.connections.spi.ConnectionProvider]

在配置文件里的配置是这样的，

<!-- C3P0连接池设定-->

<!-- 使用c3p0连接池  配置连接池提供的供应商-->

<property name="connection.provider_class">org.hibernate.connection.C3P0ConnectionProvider</property>

<!--在连接池中可用的数据库连接的最少数目 -->

<property name="c3p0.min_size">5</property>

<!--在连接池中所有数据库连接的最大数目  -->

<property name="c3p0.max_size">20</property>

<!--设定数据库连接的过期时间,以秒为单位,

如果连接池中的某个数据库连接处于空闲状态的时间超过了timeout时间,就会从连接池中清除 -->

<property name="c3p0.timeout">120</property>

<!--每3000秒检查所有连接池中的空闲连接 以秒为单位-->

<property name="c3p0.idle_test_period">3000</property>

注释掉这一行，错误没有了。

<property name="connection.provider_class">org.hibernate.connection.C3P0ConnectionProvider</property>

查看Hibernate4.3.8的手册，是这么表述的：

Hibernate‘s own connection pooling algorithm is, however, quite rudimentary. It is intended to help you get started and is not intended for use in a production system, or even for performance testing. You should use a third party pool for best performance and stability. Just replace thehibernate.connection.pool_size property with connection pool specific settings. This will turn off Hibernate‘s internal pool. For example, you might like to use c3p0.

hibernate.connection.driver_class = org.postgresql.Driver
hibernate.connection.url = jdbc:postgresql://localhost/mydatabase
hibernate.connection.username = myuser
hibernate.connection.password = secret
hibernate.c3p0.min_size=5
hibernate.c3p0.max_size=20
hibernate.c3p0.timeout=1800
hibernate.c3p0.max_statements=50
hibernate.dialect = org.hibernate.dialect.PostgreSQL82Dialect

意思是，只需要将 

hibernate.connection.pool_size替换为

hibernate.c3p0.min_size=5
hibernate.c3p0.max_size=20
hibernate.c3p0.timeout=1800
hibernate.c3p0.max_statements=50

这几个属性就ok了，没有说配置 connection.provider_class这个属性。

来自为知笔记(Wiz)