網上沒有找到比較合適的，自己看了看，然后放到項目中實驗的一下。
很多人都認為比DBCP優秀。

<bean id="c3p0DataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource" destroy-method="close">
      <property name="driverClass">
        <value>${jdbc.driverClassName}</value>
      </property>
      <property name="jdbcUrl">
        <value>${jdbc.url}</value>
      </property>
      <property name="user">
       <value>${jdbc.username}</value>
      </property>
      <property name="password">
       <value>${jdbc.password}</value>
      </property>
      <property name="initialPoolSize"><value>10</value></property>
      <property name="minPoolSize"><value>5</value></property>
      <property name="maxPoolSize"><value>30</value></property>
      <property name="acquireIncrement"><value>5</value></property>
      <property name="maxIdleTime"><value>10</value></property>
      <property name="maxStatements"><value>0</value></property>
    </bean>

以下幾個參數是使用的基本配置參數：
initialPoolSize：
Number of Connections a pool will try to acquire upon startup. Should be between minPoolSize and maxPoolSize
連接池初始化時獲取的鏈接數，介于minPoolSize和maxPoolSize之間

minPoolSize：
Minimum number of Connections a pool will maintain at any given time.
最小鏈接數

maxPoolSize：
Maximum number of Connections a pool will maintain at any given time.
最大連接數

acquireIncrement：
Determines how many connections at a time c3p0 will try to acquire when the pool is exhausted.
在當前連接數耗盡的時候，一次獲取的新的連接數

maxIdleTime：
Seconds a Connection can remain pooled but unused before being discarded. Zero means idle connections never expire.
最大空閑的時間，單位是秒，無用的鏈接再過時后會被回收