c3p0数据源配置抛出Could not load driverClass com.mysql.jdbc.Driver的解决方案

1.0 配置c3p0数据源，一直提示 无法加载数据库驱动。

但是明明有驱动，非常疑惑。。。。。

com.mchange.v2.c3p0.DriverManagerDataSource ---- Could not load driverClass com.mysql.jdbc.Driver 

  java.lang.ClassNotFoundException: com.mysql.jdbc.Driver 
    at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1311)
    at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1145)
    at java.lang.Class.forName0(Native Method)
    at java.lang.Class.forName(Class.java:264)
    at com.mchange.v2.c3p0.DriverManagerDataSource.ensureDriverLoaded(DriverManagerDataSource.java:112)
    at com.mchange.v2.c3p0.DriverManagerDataSource.getConnection(DriverManagerDataSource.java:144)
    at com.mchange.v2.c3p0.WrapperConnectionPoolDataSource.getPooledConnection(WrapperConnectionPoolDataSource.java:195)
    at com.mchange.v2.c3p0.WrapperConnectionPoolDataSource.getPooledConnection(WrapperConnectionPoolDataSource.java:184)
    at com.mchange.v2.c3p0.impl.C3P0PooledConnectionPool$1PooledConnectionResourcePoolManager.acquireResource(C3P0PooledConnectionPool.java:200)
    at com.mchange.v2.resourcepool.BasicResourcePool.doAcquire(BasicResourcePool.java:1086)
    at com.mchange.v2.resourcepool.BasicResourcePool.doAcquireAndDecrementPendingAcquiresWithinLockOnSuccess(BasicResourcePool.java:1073)
    at com.mchange.v2.resourcepool.BasicResourcePool.access$800(BasicResourcePool.java:44)
    at com.mchange.v2.resourcepool.BasicResourcePool$ScatteredAcquireTask.run(BasicResourcePool.java:1810)
    at com.mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThread.run(ThreadPoolAsynchronousRunner.java:696)

com.mchange.v2.c3p0.DriverManagerDataSource ---- Could not load driverClass com.mysql.jdbc.Driver 

查看applicationcontext.xml

仔细观察，木有任何问题

<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}"/>
  <!--   初始化建立的连接数 -->
        <property name="initialPoolSize" value="10"/>
<!--         最大空闲时间，120秒内未被使用的连接将被丢弃 -->
        <property name="maxIdleTime" value="120"/>
    <!--     当连接池耗尽，且未达到最大连接数时，一次获取的连接数 -->
        <property name="acquireIncrement" value="2"/>
    <!--     空闲检查时间间隔， 每隔120秒检查连接池里的空闲连接 ，单位是秒 -->
        <property name="idleConnectionTestPeriod" value="60"/>
    
    </bean>

查看jdbc.properties

jdbc.driverClassName=com.mysql.jdbc.Driver 
jdbc.url=jdbc\:mysql\://localhost\:3306/dftsms?useUnicode\=true&characterEncoding\=UTF8
jdbc.username=root
jdbc.password=1234
jdbc.initialPoolSize=10
jdbc.maxIdleTime=120
jdbc.acquireIncrement=2
jdbc.idleConnectionTestPeriod=60

仔仔细细看完，木有任何问题啊 ，这他么怎么回事儿。。。。。。

最后，经过多方查证，原来是jdbc.properties 文件中jdbc.driverClassName=com.mysql.jdbc.Driver,这一句配置后面有个空格。。。。。。。