<!-- 引入外部文件：jdbc.properties -->

<context:property-placeholder location="classpath:jdbc.properties"/>

<!-- 配置连接池 -->

<bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">

<property name="driverClass" value="${jdbc.driverClass}"/>

<property name="url" value="${jdbc.url}"/>

<property name="user" value="${jdbc.username}"/>

<property name="password" value="${jdbc.password}"/>

</bean>

错入如下：

Error creating bean with name 'dataSource' defined in class path resource [applicationContext.xml]: Error setting property values; nested exception is org.springframework.beans.NotWritablePropertyException: Invalid property 'url' of bean class [com.mchange.v2.c3p0.ComboPooledDataSource]: Bean property 'url' is not writable or has an invalid setter method. Does the parameter type of the setter match the return type of the getter?

Invalid property 'url' of bean class [com.mchange.v2.c3p0.ComboPooledDataSource]: Bean property 'url' is not writable or has an invalid setter method. Does the parameter type of the setter match the return type of the getter?