JSF2.0+SPRING target unreachable identifier resolved to null

类似于这样的异常：

javax.el.PropertyNotFoundException: /customer/add.xhtml @11,70 value="#{customerBean.firstName}": Target Unreachable, identifier 'customerBean' resolved to null

在faces-config.xml中添加配置：

<application>
    <el-resolver>org.springframework.web.jsf.el.SpringBeanFacesELResolver</el-resolver>
    </application>